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Berendam SJ, Morgan-Asiedu PK, Mangan RJ, Li SH, Heimsath H, Luo K, Curtis AD, Eudailey JA, Fox CB, Tomai MA, Phillips B, Itell HL, Kunz E, Hudgens M, Cronin K, Wiehe K, Alam SM, Van Rompay KKA, De Paris K, Permar SR, Moody MA, Fouda GG. Different adjuvanted pediatric HIV envelope vaccines induced distinct plasma antibody responses despite similar B cell receptor repertoires in infant rhesus macaques. PLoS One 2022; 16:e0256885. [PMID: 34972105 PMCID: PMC8719683 DOI: 10.1371/journal.pone.0256885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022] Open
Abstract
Different HIV vaccine regimens elicit distinct plasma antibody responses in both human and nonhuman primate models. Previous studies in human and non-human primate infants showed that adjuvants influenced the quality of plasma antibody responses induced by pediatric HIV envelope vaccine regimens. We recently reported that use of the 3M052-SE adjuvant and longer intervals between vaccinations are associated with higher magnitude of antibody responses in infant rhesus macaques. However, the impact of different adjuvants in HIV vaccine regimens on the developing infant B cell receptor (BCR) repertoire has not been studied. This study evaluated whether pediatric HIV envelope vaccine regimens with different adjuvants induced distinct antigen-specific memory B cell repertoires and whether specific immunoglobulin (Ig) immunogenetic characteristics are associated with higher magnitude of plasma antibody responses in vaccinated infant rhesus macaques. We utilized archived preclinical pediatric HIV vaccine studies PBMCs and tissue samples from 19 infant rhesus macaques immunized either with (i) HIV Env protein with a squalene adjuvant, (ii) MVA-HIV and Env protein co-administered using a 3-week interval, (iii) MVA-HIV prime/ protein boost with an extended 6-week interval between immunizations, or (iv) with HIV Env administered with 3M-052-SE adjuvant. Frequencies of vaccine-elicited HIV Env-specific memory B cells from PBMCs and tissues were similar across vaccination groups (frequency range of 0.06–1.72%). There was no association between vaccine-elicited antigen-specific memory B cell frequencies and plasma antibody titer or avidity. Moreover, the epitope specificity and Ig immunogenetic features of vaccine-elicited monoclonal antibodies did not differ between the different vaccine regimens. These data suggest that pediatric HIV envelope vaccine candidates with different adjuvants that previously induced higher magnitude and quality of plasma antibody responses in infant rhesus macaques were not driven by distinct antigen-specific memory BCR repertoires.
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Affiliation(s)
- Stella J. Berendam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Papa K. Morgan-Asiedu
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Riley J. Mangan
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Shuk Hang Li
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Holly Heimsath
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kan Luo
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alan D. Curtis
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Joshua A. Eudailey
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pediatrics, Weill Cornell College of Medicine, New York City, New York, United States of America
| | - Christopher B. Fox
- Infectious Disease Research Institute (IDRI), Seattle, Washington State, United States of America
- Department of Global Health, University of Washington, Seattle, Washington State, United States of America
| | - Mark A. Tomai
- 3M Center, 3 M Drug Delivery Systems, St. Paul, Minnesota, United States of America
| | - Bonnie Phillips
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hannah L. Itell
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Erika Kunz
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Michael Hudgens
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kenneth Cronin
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Koen K. A. Van Rompay
- California National Primate Research Center, University of California at Davis, Davis, California, United States of America
| | - Kristina De Paris
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sallie R. Permar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pediatrics, Weill Cornell College of Medicine, New York City, New York, United States of America
| | - M. Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Genevieve G. Fouda
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Abstract
Advances in perinatal HIV management have averted a significant number of infections in neonates and have made the possibility of elimination of mother-to-child transmission a reality; however, significant gaps in implementation of early testing programs as well as the expansion of therapeutic strategies to neonates are hindering prevention efforts and access to safer, more effective and easier to administer treatment. This article provides insights on the current state of perinatal HIV, recent advances, and future needs.
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Affiliation(s)
- Andres F Camacho-Gonzalez
- Division of Pediatric Infectious Diseases, Children's Healthcare of Atlanta, Emory University School of Medicine, 2015 Uppergate Drive, Suite 500, Atlanta, GA 30322, USA.
| | - Paul Palumbo
- Section of Infectious Diseases and International Health, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Lebanon, NH 03756, USA
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Han Q, Bradley T, Williams WB, Cain DW, Montefiori DC, Saunders KO, Parks RJ, Edwards RW, Ferrari G, Mueller O, Shen X, Wiehe KJ, Reed S, Fox CB, Rountree W, Vandergrift NA, Wang Y, Sutherland LL, Santra S, Moody MA, Permar SR, Tomaras GD, Lewis MG, Van Rompay KKA, Haynes BF. Neonatal Rhesus Macaques Have Distinct Immune Cell Transcriptional Profiles following HIV Envelope Immunization. Cell Rep 2021; 30:1553-1569.e6. [PMID: 32023469 PMCID: PMC7243677 DOI: 10.1016/j.celrep.2019.12.091] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/16/2019] [Accepted: 12/24/2019] [Indexed: 12/30/2022] Open
Abstract
HIV-1-infected infants develop broadly neutralizing antibodies (bnAbs) more rapidly than adults, suggesting differences in the neonatal versus adult responses to the HIV-1 envelope (Env). Here, trimeric forms of HIV-1 Env immunogens elicit increased gp120- and gp41-specific antibodies more rapidly in neonatal macaques than adult macaques. Transcriptome analyses of neonatal versus adult immune cells after Env vaccination reveal that neonatal macaques have higher levels of the apoptosis regulator BCL2 in T cells and lower levels of the immunosuppressive interleukin-10 (IL-10) receptor alpha (IL10RA) mRNA transcripts in T cells, B cells, natural killer (NK) cells, and monocytes. In addition, immunized neonatal macaques exhibit increased frequencies of activated blood T follicular helper-like (Tfh) cells compared to adults. Thus, neonatal macaques have transcriptome signatures of decreased immunosuppression and apoptosis compared with adult macaques, providing an immune landscape conducive to early-life immunization prior to sexual debut.
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Affiliation(s)
- Qifeng Han
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Todd Bradley
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Wilton B Williams
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Derek W Cain
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - David C Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Robert J Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Regina W Edwards
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Guido Ferrari
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Olaf Mueller
- Center for Genomics of Microbial Systems, Duke University Medical Center, Durham, NC, USA
| | - Xiaoying Shen
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Kevin J Wiehe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | | | | | - Wes Rountree
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Nathan A Vandergrift
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Yunfei Wang
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Laura L Sutherland
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Sampa Santra
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Sallie R Permar
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | | | - Koen K A Van Rompay
- California National Primate Research Center, University of California, Davis, Davis, CA, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA.
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Dispinseri S, Cavarelli M, Tolazzi M, Plebani AM, Jansson M, Scarlatti G. Continuous HIV-1 Escape from Autologous Neutralization and Development of Cross-Reactive Antibody Responses Characterizes Slow Disease Progression of Children. Vaccines (Basel) 2021; 9:vaccines9030260. [PMID: 33799407 PMCID: PMC7999787 DOI: 10.3390/vaccines9030260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 11/16/2022] Open
Abstract
The antibodies with different effector functions evoked by Human Immunodeficiency Virus type 1 (HIV-1) transmitted from mother to child, and their role in the pathogenesis of infected children remain unresolved. So, too, the kinetics and breadth of these responses remain to be clearly defined, compared to those developing in adults. Here, we studied the kinetics of the autologous and heterologous neutralizing antibody (Nab) responses, in addition to antibody-dependent cellular cytotoxicity (ADCC), in HIV-1 infected children with different disease progression rates followed from close after birth and five years on. Autologous and heterologous neutralization were determined by Peripheral blood mononuclear cells (PBMC)- and TZMbl-based assays, and ADCC was assessed with the GranToxiLux assay. The reactivity to an immunodominant HIV-1 gp41 epitope, and childhood vaccine antigens, was assessed by ELISA. Newborns displayed antibodies directed towards the HIV-1 gp41 epitope. However, antibodies neutralizing the transmitted virus were undetectable. Nabs directed against the transmitted virus developed usually within 12 months of age in children with slow progression, but rarely in rapid progressors. Thereafter, autologous Nabs persisted throughout the follow-up of the slow progressors and induced a continuous emergence of escape variants. Heterologous cross-Nabs were detected within two years, but their subsequent increase in potency and breadth was mainly a trait of slow progressors. Analogously, titers of antibodies mediating ADCC to gp120 BaL pulsed target cells increased in slow progressors during follow-up. The kinetics of antibody responses to the immunodominant viral antigen and the vaccine antigens were sustained and independent of disease progression. Persistent autologous Nabs triggering viral escape and an increase in the breadth and potency of cross-Nabs are exclusive to HIV-1 infected slowly progressing children.
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Affiliation(s)
- Stefania Dispinseri
- Viral Evolution and Transmission Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS Ospedale San Raffaele, 20132 Milan, Italy; (S.D.); (M.T.)
| | - Mariangela Cavarelli
- Inserm, CEA, Center for Immunology of Viral, Auto-Immune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), University Paris-Saclay, 92265 Fontenay-aux-Roses & Le Kremlin-Bicêtre, France;
| | - Monica Tolazzi
- Viral Evolution and Transmission Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS Ospedale San Raffaele, 20132 Milan, Italy; (S.D.); (M.T.)
| | - Anna Maria Plebani
- Pediatric Emergency Unit, Filippo Del Ponte Hospital, ASST-Settelaghi, 21100 Varese, Italy;
| | - Marianne Jansson
- Department of Laboratory Medicine, Lund University, 22242 Lund, Sweden;
| | - Gabriella Scarlatti
- Viral Evolution and Transmission Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS Ospedale San Raffaele, 20132 Milan, Italy; (S.D.); (M.T.)
- Correspondence: ; Tel.: +39-022643-4906; Fax: +39-022643-4905
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5
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Harnessing early life immunity to develop a pediatric HIV vaccine that can protect through adolescence. PLoS Pathog 2020; 16:e1008983. [PMID: 33180867 PMCID: PMC7660516 DOI: 10.1371/journal.ppat.1008983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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AIDS Vaccine Research Subcommittee (AVRS) Consultation: Early-Life Immunization Strategies against HIV Acquisition. mSphere 2019; 4:4/4/e00320-19. [PMID: 31315966 PMCID: PMC6637046 DOI: 10.1128/msphere.00320-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This report summarizes a consultation meeting convened by the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), on 12 September 2017 to discuss the scientific rationale for selectively testing relevant HIV vaccine candidates in early life that are designed to initiate immune responses for lifelong protective immunity. The urgent need to develop interventions providing durable protective immunity to HIV before sexual debut coupled with the practicality of infant vaccine schedules supports optimizing infant HIV vaccines as a high priority. The panelists discussed the unique opportunities and challenges of testing candidate HIV vaccines in the context of distinct early-life immunity. Key developments providing rationale and grounds for cautious optimism regarding evaluation of early-life HIV vaccines include recent studies of early-life immune ontogeny, studies of HIV-infected infants demonstrating relatively rapid generation of broadly neutralizing antibodies (bNAbs), discovery of novel adjuvants active in early life, and cutting-edge sample-sparing systems biology and immunologic assays promising deep insight into vaccine action in infants. Multidisciplinary efforts toward the goal of an infant HIV vaccine are under way and should be nurtured and amplified.IMPORTANCE Young adults represent one of the highest-risk groups for new HIV infections and the only group in which morbidity continues to increase. Therefore, an HIV vaccine to prevent HIV acquisition in adolescence is a top priority. The introduction of any vaccine during adolescence is challenging. This meeting discussed the opportunities and challenges of testing HIV vaccine candidates in the context of the infant immune system given recent advances in our knowledge of immune ontogeny and adjuvant design and studies demonstrating that HIV-infected infants generate broadly neutralizing antibodies, a main target of HIV vaccines, more rapidly than adults. Considering the global success of pediatric vaccines, the concept of an HIV vaccine introduced in early life holds merit and warrants testing.
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7
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Itell HL, McGuire EP, Muresan P, Cunningham CK, McFarland EJ, Borkowsky W, Permar SR, Fouda GG. Development and application of a multiplex assay for the simultaneous measurement of antibody responses elicited by common childhood vaccines. Vaccine 2018; 36:5600-5608. [PMID: 30087048 PMCID: PMC6130906 DOI: 10.1016/j.vaccine.2018.07.048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/10/2018] [Accepted: 07/18/2018] [Indexed: 11/18/2022]
Abstract
Because vaccine co-administration can affect elicited immune responses, it is important to evaluate new vaccines in the context of pre-existing vaccination schedules. This is particularly necessary for new pediatric vaccines, as the World Health Organization's infant immunization program already schedules several vaccines to be administered during the first months of life. To facilitate the assessment of inter-vaccine interference, we developed a pediatric vaccine multiplex assay (PVMA) to simultaneously measure antibodies against vaccines commonly administered to infants, including hepatitis B, Haemophilus influenzae type B, diphtheria, tetanus, pertussis, rubella, and respiratory syncytial virus (RSV). Comparison of antibody concentrations determined by enzyme-linked immunosorbent assays (ELISAs) and the PVMA demonstrated that the PVMA is highly sensitive, specific, reproducible, and accurate. Moreover, the PVMA requires half the time to assess a cohort compared to ELISAs, and only costs marginally more. Demonstrating the utility of the assay, we employed the PVMA to assess vaccine interference in the setting of a candidate vaccine, using the infant HIV vaccines from the completed Pediatric AIDS Clinical Trials Group (PACTG) protocols 230 and 326 as examples. There was no substantial difference in antibody concentrations between vaccine and placebo recipients, which suggests that HIV vaccination did not disrupt antibody responses elicited by routine pediatric vaccines. Thus, the PVMA is a reliable, high-throughput technique that requires minimal sample volume to measure multiple antibody concentrations concurrently, and is an efficient alternative to ELISAs for the measurement of vaccine-elicited antibody responses in large cohorts.
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Affiliation(s)
| | | | - Petronella Muresan
- Center for Biostatistics in AIDS Research, T.H. Chan Harvard School of Public Health, Boston, MA, USA
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HIV-1 Subtype C-Infected Children with Exceptional Neutralization Breadth Exhibit Polyclonal Responses Targeting Known Epitopes. J Virol 2018; 92:JVI.00878-18. [PMID: 29950423 PMCID: PMC6096808 DOI: 10.1128/jvi.00878-18] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 06/14/2018] [Indexed: 02/01/2023] Open
Abstract
An HIV vaccine is likely to require bNAbs, which have been shown to prevent HIV acquisition in nonhuman primates. Recent evidence suggests that HIV-infected children are inherently better at generating bNAbs than adults. Here, we show that exceptional neutralization breadth in a group of viremic HIV-1 subtype C-infected children was due to the presence of polyclonal bNAb responses. These bNAbs targeted multiple epitopes on the HIV envelope glycoprotein previously defined in adult infection, suggesting that the immature immune system recognizes HIV antigens similarly. Since elicitation of a polyclonal bNAb response is the basis of next-generation HIV envelope vaccines, further studies of how bNAb lineages are stimulated in children is warranted. Furthermore, our findings suggest that children may respond particularly well to vaccines designed to elicit antibodies to multiple bNAb epitopes. We have previously shown that HIV-1-infected children develop broader and more potent neutralizing antibody responses than adults. This study aimed to determine the antibody specificities in 16 HIV-1 subtype C-infected children who displayed exceptional neutralization breadth on a 22-multisubtype virus panel. All children were antiretroviral treatment (ART) naive with normal CD4 counts despite being infected for a median of 10.1 years with high viral loads. The specificity of broadly neutralizing antibodies (bNAbs) was determined using epitope-ablating mutants, chimeric constructs, and depletion or inhibition of activity with peptides and glycoproteins. We found that bNAbs in children largely targeted previously defined epitopes, including the V2-glycan, V3-glycan, CD4bs, and gp120-gp41 interface. Remarkably, 63% of children had antibodies targeting 2 or 3 and, in one case, 4 of these bNAb epitopes. Longitudinal analysis of plasma from a mother-child pair over 9 years showed that while they both had similar neutralization profiles, the antibody specificities differed. The mother developed antibodies targeting the V2-glycan and CD4bs, whereas bNAb specificities in the child could not be mapped until 6 years, when a minor V2-glycan response appeared. The child also developed high-titer membrane-proximal external region (MPER) binding antibodies not seen in the mother, although these were not a major bNAb specificity. Overall, exceptional neutralization breadth in this group of children may be the result of extended exposure to high antigenic load in the context of an intact immune system, which allowed for the activation of multiple B cell lineages and the generation of polyclonal responses targeting several bNAb epitopes. IMPORTANCE An HIV vaccine is likely to require bNAbs, which have been shown to prevent HIV acquisition in nonhuman primates. Recent evidence suggests that HIV-infected children are inherently better at generating bNAbs than adults. Here, we show that exceptional neutralization breadth in a group of viremic HIV-1 subtype C-infected children was due to the presence of polyclonal bNAb responses. These bNAbs targeted multiple epitopes on the HIV envelope glycoprotein previously defined in adult infection, suggesting that the immature immune system recognizes HIV antigens similarly. Since elicitation of a polyclonal bNAb response is the basis of next-generation HIV envelope vaccines, further studies of how bNAb lineages are stimulated in children is warranted. Furthermore, our findings suggest that children may respond particularly well to vaccines designed to elicit antibodies to multiple bNAb epitopes.
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HIV-Exposed Infants Vaccinated with an MF59/Recombinant gp120 Vaccine Have Higher-Magnitude Anti-V1V2 IgG Responses than Adults Immunized with the Same Vaccine. J Virol 2017; 92:JVI.01070-17. [PMID: 29021402 DOI: 10.1128/jvi.01070-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/20/2017] [Indexed: 01/23/2023] Open
Abstract
In the RV144 vaccine trial, IgG responses against the HIV envelope variable loops 1 and 2 (V1V2) were associated with decreased HIV acquisition risk. We previously reported that infants immunized with an MF59-adjuvanted rgp120 vaccine developed higher-magnitude anti-V1V2 IgG responses than adult RV144 vaccinees. To determine whether the robust antibody response in infants is due to differences in vaccine regimens or to inherent differences between the adult and infant immune systems, we compared Env-specific IgG responses in adults and infants immunized with the same MF59- and alum-adjuvanted HIV envelope vaccines. At peak immunogenicity, the magnitudes of the gp120- and V1V2-specific IgG responses were comparable between adults and infants immunized with the alum/MNrgp120 vaccine (gp120 median fluorescence intensities [FIs] in infants = 7,118 and in adults = 11,510, P = 0.070; V1V2 median MFIs of 512 [infants] and 804 [adults], P = 0.50), whereas infants immunized with the MF59/SF-2 rgp120 vaccine had higher-magnitude antibody levels than adults (gp120 median FIs of 15,509 [infants] and 2,290 [adults], P < 0.001; V1V2 median FIs of 23,926 [infants] and 1,538 [adults]; P < 0.001). Six months after peak immunogenicity, infants maintained higher levels Env-specific IgG than adults. Anti-V1V2 IgG3 antibodies that were associated with decreased HIV-1 risk in RV144 vaccinees were present in 43% of MF59/rgp120-vaccinated infants but only in 12% of the vaccinated adults (P = 0.0018). Finally, in contrast to the rare vaccine-elicited Env-specific IgA in infants, rgp120 vaccine-elicited Env-specific IgA was frequently detected in adults. Our results suggest that vaccine adjuvants differently modulate gp120-specific antibody responses in adults and infants and that infants can robustly respond to HIV Env immunization.IMPORTANCE More than 150,000 pediatric HIV infections occur yearly, despite the availability of antiretroviral prophylaxis. A pediatric HIV vaccine could reduce the number of these ongoing infant infections and also prime for long-term immunity prior to sexual debut. We previously reported that immunization of infants with an MF59-adjuvanted recombinant gp120 vaccine induced higher-magnitude, potentially protective anti-V1V2 IgG responses than in adult vaccinees receiving the moderately effective RV144 vaccine. In the present study, we demonstrate that the robust response observed in infants is not due to differences in vaccine regimen or vaccine dose between adults and infants. Our results suggest that HIV vaccine adjuvants may differentially modulate immune responses in adults and infants, highlighting the need to conduct vaccine trials in pediatric populations.
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Impact of Poxvirus Vector Priming, Protein Coadministration, and Vaccine Intervals on HIV gp120 Vaccine-Elicited Antibody Magnitude and Function in Infant Macaques. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00231-17. [PMID: 28814388 DOI: 10.1128/cvi.00231-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 08/12/2017] [Indexed: 12/13/2022]
Abstract
Despite success in reducing vertical HIV transmission by maternal antiretroviral therapy, several obstacles limit its efficacy during breastfeeding, and breast-milk transmission is now the dominant mode of mother-to-child transmission (MTCT) of HIV in infants. Thus, a pediatric vaccine is needed to eradicate oral HIV infections in newborns and infants. Utilizing the infant rhesus macaque model, we compared 3 different vaccine regimens: (i) HIV envelope (Env) protein only, (ii) poxvirus vector (modified vaccinia virus Ankara [MVA])-HIV Env prime and HIV Env boost, and (iii) coadministration of HIV Env and MVA-HIV Env at all time points. The vaccines were administered with an accelerated, 3-week-interval regimen starting at birth for early induction of highly functional HIV Env-specific antibodies. We also tested whether an extended, 6-week immunization interval using the same vaccine regimen as in the coadministration group would enhance the quality of antibody responses. We found that pediatric HIV vaccines administered at birth are effective in inducing HIV Env-specific plasma IgG. The vaccine regimen consisting of only HIV Env protein induced the highest levels of variable region 1 and 2 (V1V2)-specific antibodies and tier 1 neutralizing antibodies, whereas the extended-interval regimen induced both persistent Env-specific systemic IgG and mucosal IgA responses. Antibody-dependent cell-mediated cytotoxicity (ADCC) antibodies in plasma were elicited by all vaccine regimens. These data suggest that infant immunizations beginning at birth are effective for the induction of functional HIV Env-specific antibodies that could potentially protect against breast milk transmission of HIV and set the stage for immunity prior to sexual debut.
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Muturi-Kioi V, Lewis D, Launay O, Leroux-Roels G, Anemona A, Loulergue P, Bodinham CL, Aerssens A, Groth N, Saul A, Podda A. Neutropenia as an Adverse Event following Vaccination: Results from Randomized Clinical Trials in Healthy Adults and Systematic Review. PLoS One 2016; 11:e0157385. [PMID: 27490698 PMCID: PMC4974007 DOI: 10.1371/journal.pone.0157385] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND In the context of early vaccine trials aimed at evaluating the safety profile of novel vaccines, abnormal haematological values, such as neutropenia, are often reported. It is therefore important to evaluate how these trials should be planned not to miss potentially important safety signals, but also to understand the implications and the clinical relevance. METHODOLOGY We report and discuss the results from five clinical trials (two with a new Shigella vaccine in the early stage of clinical development and three with licensed vaccines) where the absolute neutrophil counts (ANC) were evaluated before and after vaccination. Additionally, we have performed a systematic review of the literature on cases of neutropenia reported during vaccine trials to discuss our results in a more general context. PRINCIPAL FINDINGS Both in our clinical trials and in the literature review, several cases of neutropenia have been reported, in the first two weeks after vaccination. However, neutropenia was generally transient and had a benign clinical outcome, after vaccination with either multiple novel candidates or well-known licensed vaccines. Additionally, the vaccine recipients with neutropenia frequently had lower baseline ANC than non-neutropenic vaccinees. In many instances neutropenia occurred in subjects of African descent, known to have lower ANC compared to western populations. CONCLUSIONS It is important to include ANC and other haematological tests in early vaccine trials to identify potential safety signals. Post-vaccination neutropenia is not uncommon, generally transient and clinically benign, but many vaccine trials do not have a sampling schedule that allows its detection. Given ethnic variability in the level of circulating neutrophils, normal ranges taking into account ethnicity should be used for determination of trial inclusion/exclusion criteria and classification of neutropenia related adverse events. TRIAL REGISTRATION ClinicalTrials.gov NCT02017899, NCT02034500, NCT01771367, NCT01765413, NCT02523287.
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Affiliation(s)
| | - David Lewis
- Surrey Clinical Research Centre, University of Surrey, Guildford, United Kingdom
| | - Odile Launay
- Université Paris Descartes, Sorbonne Paris cité, and Inserm CIC 1417, F-CRIN I-Reivac, Assistance Publique Hôpitaux de Paris, CIC Cochin-Pasteur, Paris, France
| | | | | | - Pierre Loulergue
- Université Paris Descartes, Sorbonne Paris cité, and Inserm CIC 1417, F-CRIN I-Reivac, Assistance Publique Hôpitaux de Paris, CIC Cochin-Pasteur, Paris, France
| | - Caroline L. Bodinham
- Surrey Clinical Research Centre, University of Surrey, Guildford, United Kingdom
| | | | | | - Allan Saul
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Audino Podda
- Novartis Vaccines Institute for Global Health, Siena, Italy
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13
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Lee KL, Twyman RM, Fiering S, Steinmetz N. Virus-based nanoparticles as platform technologies for modern vaccines. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2016; 8:554-78. [PMID: 26782096 PMCID: PMC5638654 DOI: 10.1002/wnan.1383] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/11/2015] [Indexed: 12/25/2022]
Abstract
Nanoscale engineering is revolutionizing the development of vaccines and immunotherapies. Viruses have played a key role in this field because they can function as prefabricated nanoscaffolds with unique properties that are easy to modify. Viruses are immunogenic via multiple pathways, and antigens displayed naturally or by engineering on the surface can be used to create vaccines against the cognate virus, other pathogens, specific molecules or cellular targets such as tumors. This review focuses on the development of virus-based nanoparticle systems as vaccines indicated for the prevention or treatment of infectious diseases, chronic diseases, cancer, and addiction. WIREs Nanomed Nanobiotechnol 2016, 8:554-578. doi: 10.1002/wnan.1383 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Karin L. Lee
- Department of Biomedical Engineering, Case Western Reserve University Schools of Engineering and Medicine, Cleveland, OH 44106
| | | | - Steven Fiering
- Department of Microbiology and Immunology and Norris Cotton Cancer Center, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03756
| | - Nicole Steinmetz
- Departments of Biomedical Engineering, Radiology, Materials Science and Engineering, and Macromolecular Science and Engineering, Case Western Reserve University and Medicine, Cleveland, OH 44106;
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Abstract
PURPOSE OF REVIEW The known timing of HIV infection in perinatal transmission, combined with the capacity for early antiretroviral therapy (ART) initiation and immune reconstitution, can provide unique insights into HIV persistence. The scientific basis for a pediatric-specific research agenda aimed at HIV remission and cure is discussed. RECENT FINDINGS Accumulating evidence supports a favorable biomarker profile for immunotherapeutic interventions in early treated, perinatally infected individuals. HIV DNA concentrations in infected cells of early treated infants decrease over the first few years of life and, after more than 10 years of ART, the overwhelming majority of noninduced proviral genomes are replication-deficient. With early ART initiation, approximately half of perinatally infected individuals become seronegative. Studies of untreated infants and vaccine trials indicate that infected infants can generate HIV-specific humoral responses. Taken together, this evidence suggests that early treatment results in low levels of replication-competent provirus, an absence of HIV-specific immunity, and the capacity to generate immune responses to potential immunotherapeutic interventions. SUMMARY Perinatally HIV-infected individuals require lifelong ART because of the prompt establishment of viral latency in long-lived resting memory CD4 T cells that rekindle viremia upon treatment cessation. However, intense research efforts are ongoing to perturb HIV latency toward reservoir clearance for virologic remission and cure in which perinatally infected individuals can discontinue ART.
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Abstract
PURPOSE OF REVIEW Although antiretroviral (ARV) prophylaxis can reduce mother-to-child transmission (MTCT) of HIV-1 to less than 2%, one-quarter of a million infants continue to be infected with HIV-1 annually. ARV prophylaxis alone will fail to eliminate infant HIV-1 infection because of issues of maternal adherence, toxicities, ARV-resistant virus strains, and acute maternal infection. Effective maternal and/or infant immunization will likely be required to achieve the goal of an HIV-free generation. RECENT FINDINGS This article describes recent studies of antibody responses that protect against vertical HIV-1 transmission. Studies have shown that maternal neutralization breadth is not a critical factor in MTCT, yet the ability of maternal plasma to neutralize autologous virus variants may be important in infant protection. There is also new evidence that infants mount robust and durable antibody responses to HIV-1 envelope following vaccination and can develop broad neutralization during infection. Finally, passive immunization of infants with highly potent and broad neutralizing antibodies may be an effective strategy to protect infants against infection with postnatally transmitted variants. SUMMARY Defining the characteristics of maternal and infant antibody responses that protect against MTCT will inform development of effective passive and active immunization strategies that will likely be required to eliminate pediatric HIV-1.
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Contrasting Adult and Infant Immune Responses to HIV Infection and Vaccination. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 23:84-94. [PMID: 26656117 DOI: 10.1128/cvi.00565-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Extensive studies have demonstrated that infant immune responses are distinct from those of adults. Despite these differences, infant immunization can elicit protective immune responses at levels comparable to or, in some cases, higher than adult immune responses to many vaccines. To date, only a few HIV vaccine candidates have been tested in infant populations, and none of them evaluated vaccine efficacy. Recent exciting studies showing that HIV-infected infants can develop broad neutralizing antibody responses and that some HIV vaccine regimens can elicit high levels of potentially protective antibodies in infants provide support for the development and testing of HIV vaccines in pediatric populations. In this review, we discuss the differences in adult and infant immune responses in the setting of HIV infection and vaccination.
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Karasavvas N, Karnasuta C, Savadsuk H, Madnote S, Inthawong D, Chantakulkij S, Rittiroongrad S, Nitayaphan S, Pitisuttithum P, Thongcharoen P, Siriyanon V, Andrews CA, Barnett SW, Tartaglia J, Sinangil F, Francis DP, Robb ML, Michael NL, Ngauy V, de Souza MS, Paris RM, Excler JL, Kim JH, O'Connell RJ. IgG Antibody Responses to Recombinant gp120 Proteins, gp70V1/V2 Scaffolds, and a CyclicV2 Peptide in Thai Phase I/II Vaccine Trials Using Different Vaccine Regimens. AIDS Res Hum Retroviruses 2015; 31:1178-86. [PMID: 26234467 PMCID: PMC4651018 DOI: 10.1089/aid.2015.0034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
RV144 correlates of risk analysis showed that IgG antibodies to gp70V1V2 scaffolds inversely correlated with risk of HIV acquisition. We investigated IgG antibody responses in RV135 and RV132, two ALVAC-HIV prime-boost vaccine trials conducted in Thailand prior to RV144. Both trials used ALVAC-HIV (vCP1521) at 0, 1, 3, and 6 months and HIV-1 gp120MNgD and gp120A244gD in alum (RV135) or gp120SF2 and gp120CM235 in MF59 (RV132) at 3 and 6 months. We assessed ELISA binding antibodies to the envelope proteins (Env) 92TH023, A244gD and MNgD, cyclicV2, and gp70V1V2 CaseA2 (subtype B) and 92TH023 (subtype CRF01_AE), and Env-specific IgG1 and IgG3. Antibody responses to gp120 A244gD, MNgD, and gp70V1V2 92TH023 scaffold were significantly higher in RV135 than in RV132. Antibodies to gp70V1V2 CaseA2 were detected only in RV135 vaccine recipients and IgG1 and IgG3 antibody responses to A244gD were significantly higher in RV135. IgG binding to gp70V1V2 CaseA2 and CRF01_AE scaffolds was higher with the AIDSVAX®B/E boost but both trials showed similar rates of antibody decline post-vaccination. MF59 did not result in higher IgG antibody responses compared to alum with the antigens tested. However, notable differences in the structure of the recombinant proteins and dosage used for immunizations may have contributed to the magnitude and specificity of IgG induced by the two trials.
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Affiliation(s)
- Nicos Karasavvas
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chitraporn Karnasuta
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Hathairat Savadsuk
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Sirinan Madnote
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Dutsadee Inthawong
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Somsak Chantakulkij
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Surawach Rittiroongrad
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Sorachai Nitayaphan
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | | | - Vinai Siriyanon
- Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand
| | | | - Susan W. Barnett
- Novartis Vaccines and Diagnostics, Inc., Cambridge, Massachusetts
| | | | - Faruk Sinangil
- Global Solutions for Infectious Diseases (GSID), South San Francisco, California
| | - Donald P. Francis
- Global Solutions for Infectious Diseases (GSID), South San Francisco, California
| | - Merlin L. Robb
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Nelson L. Michael
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Viseth Ngauy
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Mark S. de Souza
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Robert M. Paris
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jean-Louis Excler
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Jerome H. Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - Robert J. O'Connell
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
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Klein N, Palma P, Luzuriaga K, Pahwa S, Nastouli E, Gibb DM, Rojo P, Borkowsky W, Bernardi S, Zangari P, Calvez V, Compagnucci A, Wahren B, Foster C, Munoz-Fernández MÁ, De Rossi A, Ananworanich J, Pillay D, Giaquinto C, Rossi P. Early antiretroviral therapy in children perinatally infected with HIV: a unique opportunity to implement immunotherapeutic approaches to prolong viral remission. THE LANCET. INFECTIOUS DISEASES 2015; 15:1108-1114. [PMID: 26187030 DOI: 10.1016/s1473-3099(15)00052-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 05/04/2015] [Accepted: 05/08/2015] [Indexed: 02/02/2023]
Abstract
From the use of antiretroviral therapy to prevent mother-to-child transmission to the possibility of HIV cure hinted at by the Mississippi baby experience, paediatric HIV infection has been pivotal to our understanding of HIV pathogenesis and management. Daily medication and indefinite antiretroviral therapy is recommended for children infected with HIV. Maintenance of life-long adherence is difficult and the incidence of triple-class virological failure after initiation of antiretroviral therapy increases with time. This challenge shows the urgent need to define novel strategies to provide long-term viral suppression that will allow safe interruption of antiretroviral therapy without viral rebound and any associated complications. HIV-infected babies treated within a few days of birth have a unique combination of a very small pool of integrated viruses, a very high proportion of relatively HIV resistant naive T cells, and an unparalleled capacity to regenerate an immune repertoire. These features make this group the optimum model population to investigate the potential efficacy of immune-based therapies. If successful, these investigations could change the way we manage HIV infection.
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Affiliation(s)
- Nigel Klein
- Institute of Child Health, University College London, London, UK.
| | - Paolo Palma
- University Department of Pediatrics, Unit of Immune and Infectious Diseases, Children's Hospital Bambino Gesù, Rome, Italy
| | - Katherine Luzuriaga
- Program in Molecular Medicine, University of Massachusetts Medical School Worcester, MA, USA
| | - Savita Pahwa
- Miami Center for AIDS Research Department of Microbiology and Immunology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Eleni Nastouli
- Department of Virology, University College London, London, UK
| | - Diane M Gibb
- Medical Research Council Clinical Trials Unit, London, UK
| | - Pablo Rojo
- Department of Pediatrics, Hospital 12 de Octubre, Madrid, Spain
| | | | - Stefania Bernardi
- University Department of Pediatrics, Unit of Immune and Infectious Diseases, Children's Hospital Bambino Gesù, Rome, Italy
| | - Paola Zangari
- University Department of Pediatrics, Unit of Immune and Infectious Diseases, Children's Hospital Bambino Gesù, Rome, Italy
| | - Vincent Calvez
- Pierre et Marie Curie University and Pitié-Salpêtrière Hospital, Paris, France
| | - Alexandra Compagnucci
- Institut National de la Santé et de la Recherche Médicale SC10-US019 Clinical Trials and Infectious Diseases, Villejuif, Paris, France
| | - Britta Wahren
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Caroline Foster
- Imperial College Healthcare National Health Service Trust, London, UK
| | | | - Anita De Rossi
- Section of Oncology and Immunology, Department of Surgery, Oncology and Gastroenterology-DiSCOG, University of Padova, and Istituto Oncologico Veneto, Padova, Italy
| | - Jintanat Ananworanich
- US Military HIV Research Program, Walter Reed Army Institute of Research and Henry M Jackson Foundation for the Advancement of Military Medicine, Silver Spring, MD, USA
| | - Deenan Pillay
- Africa Centre, Mtubatuba, KwaZulu Natal, South Africa
| | - Carlo Giaquinto
- Department of Women's and Children's Health, University of Padova, and Penta Foundation, Padova, Italy
| | - Paolo Rossi
- University Department of Pediatrics, Unit of Immune and Infectious Diseases, Children's Hospital Bambino Gesù, Rome, Italy.
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Fouda GG, Cunningham CK, Permar SR. Infant HIV-1 vaccines: supplementing strategies to reduce maternal-child transmission. JAMA 2015; 313:1513-4. [PMID: 25898044 PMCID: PMC4520313 DOI: 10.1001/jama.2015.1382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Genevieve G Fouda
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina2Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina
| | - Coleen K Cunningham
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina
| | - Sallie R Permar
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina2Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina
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20
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Fouda GG, Permar SR. Immune-based interventions to prevent postnatal HIV-1 transmission. Trends Microbiol 2015; 22:425-7. [PMID: 25086471 DOI: 10.1016/j.tim.2014.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/11/2014] [Accepted: 04/17/2014] [Indexed: 02/04/2023]
Abstract
Despite global scale-up in antiretroviral-based prevention of mother-to-child transmission services, more than 250 000 infants become infected with HIV-1 each year. Breast milk transmission is responsible for almost half of these infections. The development of alternative strategies to prevent postnatal HIV-1 transmission is imperative to achieve a generation free of HIV-1.
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Affiliation(s)
- Genevieve G Fouda
- Department of Pediatrics and Human Vaccine Institute, Duke University Medical Center, Durham, NC 27705, USA
| | - Sallie R Permar
- Department of Pediatrics and Human Vaccine Institute, Duke University Medical Center, Durham, NC 27705, USA.
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21
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Hurst SA, Appelgren KE, Kourtis AP. Prevention of mother-to-child transmission of HIV type 1: the role of neonatal and infant prophylaxis. Expert Rev Anti Infect Ther 2015; 13:169-81. [PMID: 25578882 PMCID: PMC4470389 DOI: 10.1586/14787210.2015.999667] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The prevention of mother-to-child transmission (PMTCT) of HIV is one of the great public health successes of the past 20 years. Much concerted research efforts and dedicated work have led to the achievement of very low rates of PMTCT of HIV in settings that can implement optimal prophylaxis. Though several implementation challenges remain, global elimination of pediatric HIV infection seems now more than ever to be an attainable goal. Often overlooked, the role of prophylaxis of the newborn is nevertheless a very important component of PMTCT. In this paper, we focus on the role of neonatal and infant prophylaxis, discuss mechanisms of protection, and present the clinical trial-generated evidence that led to the current recommendations for preventing infections in breastfed and non-breastfed infants. PMTCT of HIV should not end at birth; a continuum of care extending postpartum and postnatally is required to minimize the risk of new pediatric HIV infections.
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Affiliation(s)
- Stacey A. Hurst
- Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Kristie E. Appelgren
- Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Athena P. Kourtis
- Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
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22
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Njuguna IN, Ambler G, Reilly M, Ondondo B, Kanyugo M, Lohman-Payne B, Gichuhi C, Borthwick N, Black A, Mehedi SR, Sun J, Maleche-Obimbo E, Chohan B, John-Stewart GC, Jaoko W, Hanke T. PedVacc 002: a phase I/II randomized clinical trial of MVA.HIVA vaccine administered to infants born to human immunodeficiency virus type 1-positive mothers in Nairobi. Vaccine 2014; 32:5801-8. [PMID: 25173484 PMCID: PMC4414927 DOI: 10.1016/j.vaccine.2014.08.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/07/2014] [Accepted: 08/15/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND A safe, effective vaccine for breastfeeding infants born to HIV-1-positive mothers could complement antiretroviral therapy (ART) for prevention of mother-to-child transmission of HIV-1. To date, only a few HIV-1 vaccine candidates have been tested in infants. TRIAL DESIGN A phase I/II randomized controlled trial PedVacc 002 was conducted to determine the safety and immunogenicity of a single, low dose of MVA.HIVA vaccine delivered intramuscularly to healthy 20-week-old infants born to HIV-1-positive mothers in Nairobi, Kenya. METHODS Pregnant HIV-1-positive women in the 2nd/3rd trimester of gestation were enrolled, provided with ART and self-selected their infant-feeding modality. Infants received nevirapine and cotrimoxazole prophylaxis. At 20 weeks of age, eligible HIV-1-negative infants were randomized to vaccine versus no-treatment arms and followed to 48 weeks of age for assessments of vaccine safety, HIV-1-specific T-cell responses and antibodies to routine childhood vaccines. RESULTS Between February and November 2010, 182 mothers were screened, 104 were eligible and followed on ART during pregnancy/postpartum, of whom 73 had eligible infants at 20 weeks postpartum. Thirty-six infants were randomized to vaccine and 37 to no treatment. Eighty-four percent of infants breastfed, and retention at 48 weeks was 99%. Adverse events were rare and similar between the two arms. HIV-1-specific T-cell frequencies in interferon-γ ELISPOT assay were transiently higher in the MVA.HIVA arm (p=0.002), but not above the threshold for a positive assay. Protective antibody levels were adequate and similar between arms for all routine childhood vaccines except HBV, where 71% of MVA.HIVA subjects compared to 92% of control subjects were protected (p=0.05). CONCLUSIONS This trial tested for the first time an MVA-vectored candidate HIV-1 vaccine in HIV-1-exposed infants in Africa, demonstrating trial feasibility and vaccine safety, low immunogenicity, and compatibility with routine childhood vaccinations. These results are reassuring for use of the MVA vector in more potent prime-boost regimens.
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Affiliation(s)
- Irene N Njuguna
- Department of Pediatrics and Child Health, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Gwen Ambler
- Department of Global Health, University of Washington, Seattle, WA 98104, USA
| | - Marie Reilly
- Department of Medical Epidemiology and Biostatistics, Karolinska Institute, SE-17177 Stockholm, Sweden
| | | | - Mercy Kanyugo
- Department of Pediatrics and Child Health, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Barbara Lohman-Payne
- Department of Pediatrics and Child Health, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Christine Gichuhi
- Department of Clinical Medicine and Therapeutics, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | | | - Antony Black
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Shams-Rony Mehedi
- Statistics and Data Management Department, Medical Research Council Unit, Fajara, The Gambia
| | - Jiyu Sun
- Department of Medical Epidemiology and Biostatistics, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - Elizabeth Maleche-Obimbo
- Department of Pediatrics and Child Health, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Bhavna Chohan
- Department of Pediatrics and Child Health, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Grace C John-Stewart
- Departments of Pediatrics, Medicine, Epidemiology, and Global Health, University of Washington, Seattle, WA 98104, USA
| | - Walter Jaoko
- KAVI-Institute of Clinical Research, University of Nairobi, PO Box 19676, 00202 Nairobi, Kenya
| | - Tomáš Hanke
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK; The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
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23
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Fouda GG, Cunningham CK, McFarland EJ, Borkowsky W, Muresan P, Pollara J, Song LY, Liebl BE, Whitaker K, Shen X, Vandergrift NA, Overman RG, Yates NL, Moody MA, Fry C, Kim JH, Michael NL, Robb M, Pitisuttithum P, Kaewkungwal J, Nitayaphan S, Rerks-Ngarm S, Liao HX, Haynes BF, Montefiori DC, Ferrari G, Tomaras GD, Permar SR. Infant HIV type 1 gp120 vaccination elicits robust and durable anti-V1V2 immunoglobulin G responses and only rare envelope-specific immunoglobulin A responses. J Infect Dis 2014; 211:508-17. [PMID: 25170104 DOI: 10.1093/infdis/jiu444] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Infant responses to vaccines can be impeded by maternal antibodies and immune system immaturity. It is therefore unclear whether human immunodeficiency virus type 1 (HIV-1) vaccination would elicit similar responses in adults and infants. METHOD HIV-1 Env-specific antibody responses were evaluated in 2 completed pediatric vaccine trials. In the Pediatric AIDS Clinical Trials Group (PACTG) 230 protocol, infants were vaccinated with 4 doses of Chiron rgp120 with MF59 (n=48), VaxGen rgp120 with aluminum hydroxide (alum; n=49), or placebo (n=19) between 0 and 20 weeks of age. In PACTG 326, infants received 4 doses of ALVAC-HIV-1/AIDSVAX B/B with alum (n=9) or placebo (n=13) between 0 and 12 weeks of age. RESULTS By 52 weeks of age, the majority of maternally acquired antibodies had waned and vaccine Env-specific immunoglobulin G (IgG) responses in vaccinees were higher than in placebo recipients. Chiron vaccine recipients had higher and more-durable IgG responses than VaxGen vaccine recipients or ALVAC/AIDSVAX vaccinees, with vaccine-elicited IgG responses still detectable in 56% of recipients at 2 years of age. Remarkably, at peak immunogenicity, the concentration of anti-V1V2 IgG, a response associated with a reduced risk of HIV-1 acquisition in the RV144 adult vaccine trial, was 22-fold higher in Chiron vaccine recipients, compared with RV144 vaccinees. CONCLUSION As exemplified by the Chiron vaccine regimen, vaccination of infants against HIV-1 can induce robust, durable Env-specific IgG responses, including anti-V1V2 IgG.
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Affiliation(s)
| | | | | | | | - Petronella Muresan
- Frontier Science and Technology Research Foundation Statistical and Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts
| | | | - Lin Ye Song
- Statistical and Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts
| | | | | | | | | | | | | | | | - Carrie Fry
- Frontier Science and Technology Research Foundation Statistical and Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts
| | - Jerome H Kim
- Military HIV Research Program, Bethesda, Maryland
| | | | - Merlin Robb
- Military HIV Research Program, Bethesda, Maryland
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Kaleebu P, Njai HF, Wang L, Jones N, Ssewanyana I, Richardson P, Kintu K, Emel L, Musoke P, Fowler MG, Ou SS, Guay L, Andrew P, Baglyos L, team HC. Immunogenicity of ALVAC-HIV vCP1521 in infants of HIV-1-infected women in Uganda (HPTN 027): the first pediatric HIV vaccine trial in Africa. J Acquir Immune Defic Syndr 2014; 65:268-77. [PMID: 24091694 PMCID: PMC4171956 DOI: 10.1097/01.qai.0000435600.65845.31] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Maternal-to-child-transmission of HIV-1 infection remains a significant cause of HIV-1 infection despite successful prevention strategies. Testing protective HIV-1 vaccines remains a critical priority. The immunogenicity of ALVAC-HIV vCP1521 (ALVAC) in infants born to HIV-1-infected women in Uganda was evaluated in the first pediatric HIV-1 vaccine study in Africa. DESIGN HIV Prevention Trials Network 027 was a randomized, double-blind, placebo-controlled phase I trial to evaluate the safety and immunogenicity of ALVAC in 60 infants born to HIV-1-infected mothers with CD4 counts of >500 cells per microliter, which were randomized to the ALVAC vaccine or placebo. ALVAC-HIV vCP1521 is an attenuated recombinant canarypox virus expressing HIV-1 clade E env, clade B gag, and protease gene products. METHODS Infants were vaccinated at birth and 4, 8, and 12 weeks of age with ALVAC or placebo. Cellular and humoral immune responses were evaluated using interferon-γ enzyme-linked immunosorbent spot, carboxyfluorescein diacetate succinimidyl ester proliferation, intracellular cytokine staining, and binding and neutralizing antibody assays. Fisher exact test was used to compare positive responses between the study arms. RESULTS Low levels of antigen-specific CD4 and CD8 T-cell responses (intracellular cytokine assay) were detected at 24 months (CD4-6/36 vaccine vs. 1/9 placebo; CD8-5/36 vaccine vs. 0/9 placebo) of age. There was a nonsignificant trend toward higher cellular immune response rates in vaccine recipients compared with placebo. There were minimal binding antibody responses and no neutralizing antibodies detected. CONCLUSIONS HIV-1-exposed infants are capable of generating low levels of cellular immune responses to ALVAC vaccine, similar to responses seen in adults.
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Affiliation(s)
- Pontiano Kaleebu
- Medical Research Council/Uganda Virus Research Institute, Nakiwogo Road, PO Box 49 Entebbe, Uganda
| | - Harr Freeya Njai
- Medical Research Council/Uganda Virus Research Institute, Nakiwogo Road, PO Box 49 Entebbe, Uganda
| | - Lei Wang
- SCHARP, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, LE-400, PO Box 19024, Seattle, WA, USA 98109
| | - Norman Jones
- Viral and Rickettsial Disease Laboratory, 850 Marina Bay Parkway, Richmond, CA, USA 94804
| | - Isaac Ssewanyana
- Joint Clinical Research Center, Plot 101, Upper Lubowa Estates, PO Box 10005, Kampala, Uganda
| | - Paul Richardson
- Johns Hopkins University School of Medicine, 600 North Wolfe Street, Pathology 313, Baltimore, MD, USA 21287
| | - Kenneth Kintu
- Makerere University-Johns Hopkins University Research Collaboration, PO Box 7072, Kampala, Uganda
| | - Lynda Emel
- SCHARP, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, LE-400, PO Box 19024, Seattle, WA, USA 98109
| | - Philippa Musoke
- Makerere University-Johns Hopkins University Research Collaboration, PO Box 7072, Kampala, Uganda
- Department of Paediatrics and Child Health, College of Health Sciences, Makerere University, PO Box 7072, Kampala, Uganda
| | - Mary Glenn Fowler
- Johns Hopkins University School of Medicine, 600 North Wolfe Street, Pathology 313, Baltimore, MD, USA 21287
| | - San-San Ou
- SCHARP, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, LE-400, PO Box 19024, Seattle, WA, USA 98109
| | - Laura Guay
- George Washington University School of Public Health and Health Services, 2100 W. Pennsylvania Avenue N.W., 8th Floor, Washington DC, USA 20037
| | | | - Lynn Baglyos
- Sanofi Pasteur, Discovery Drive, Swiftwater, PA, USA 18370
| | - Huyen Cao team
- Viral and Rickettsial Disease Laboratory, 850 Marina Bay Parkway, Richmond, CA, USA 94804
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Abstract
PURPOSE OF REVIEW We review the broad spectrum of nonreplicating viral vectors which have been studied extensively, from preclinical studies through clinical efficacy trials, and include some of our most promising HIV vaccine candidates. RECENT FINDINGS The success of the RV144 trial, with a canarypox virus-based regimen, contrasts with the failures of the adenovirus-5 (Ad5)-based regimens in the Step study, the Phambili study [HIV Vaccine Trials Network (HVTN) 503], and the HVTN 505 study which was recently modified to halt vaccinations because of clinical futility. SUMMARY The safety profile, immunogenicity, and variety of available candidates make the nonreplicating viral vectors attractive in HIV vaccine development. Building from the success of the RV144 study, further studies of Orthopoxvirus-based vaccines, including vaccinia-based vaccines, are ongoing and planned for the future. Despite the failures of the Ad5-based vaccines in clinical efficacy trials, other adenovirus serotypes remain promising candidates, especially in prime-boost combination with other products, and with the potential use of mosaic inserts. Other nonreplicating viral vectors such as the rhabdoviruses, alphaviruses, and the nonhuman adenoviruses, provide additional avenues for exploration.
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Afolabi MO, Ndure J, Drammeh A, Darboe F, Mehedi SR, Rowland-Jones SL, Borthwick N, Black A, Ambler G, John-Stewart GC, Reilly M, Hanke T, Flanagan KL. A phase I randomized clinical trial of candidate human immunodeficiency virus type 1 vaccine MVA.HIVA administered to Gambian infants. PLoS One 2013; 8:e78289. [PMID: 24205185 PMCID: PMC3813444 DOI: 10.1371/journal.pone.0078289] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 09/07/2013] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND A vaccine to decrease transmission of human immunodeficiency virus type 1 (HIV-1) during breast-feeding would complement efforts to eliminate infant HIV-1 infection by antiretroviral therapy. Relative to adults, infants have distinct immune development, potentially high-risk of transmission when exposed to HIV-1 and rapid progression to AIDS when infected. To date, there have been only three published HIV-1 vaccine trials in infants. TRIAL DESIGN We conducted a randomized phase I clinical trial PedVacc 001 assessing the feasibility, safety and immunogenicity of a single dose of candidate vaccine MVA.HIVA administered intramuscularly to 20-week-old infants born to HIV-1-negative mothers in The Gambia. METHODS Infants were followed to 9 months of age with assessment of safety, immunogenicity and interference with Expanded Program on Immunization (EPI) vaccines. The trial is the first stage of developing more complex prime-boost vaccination strategies against breast milk transmission of HIV-1. RESULTS From March to October 2010, 48 infants (24 vaccine and 24 no-treatment) were enrolled with 100% retention. The MVA.HIVA vaccine was safe with no difference in adverse events between vaccinees and untreated infants. Two vaccine recipients (9%) and no controls had positive ex vivo interferon-γ ELISPOT assay responses. Antibody levels elicited to the EPI vaccines, which included diphtheria, tetanus, whole-cell pertussis, hepatitis B virus, Haemophilus influenzae type b and oral poliovirus, reached protective levels for the vast majority and were similar between the two arms. CONCLUSIONS A single low-dose of MVA.HIVA administered to 20-week-old infants in The Gambia was found to be safe and without interference with the induction of protective antibody levels by EPI vaccines, but did not alone induce sufficient HIV-1-specific responses. These data support the use of MVA carrying other transgenes as a boosting vector within more complex prime-boost vaccine strategies against transmission of HIV-1 and/or other infections in this age group. TRIAL REGISTRATION ClinicalTrials.gov NCT00982579. The Pan African Clinical Trials Registry PACTR2008120000904116.
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Affiliation(s)
| | - Jorjoh Ndure
- Vaccinology Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Abdoulie Drammeh
- Vaccinology Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Fatoumatta Darboe
- Vaccinology Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Shams-Rony Mehedi
- Statistics and Data Management Department, Medical Research Council Unit, Fajara, The Gambia
| | | | - Nicola Borthwick
- Departments of Biostatistics, Medicine, and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Antony Black
- Departments of Biostatistics, Medicine, and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Gwen Ambler
- Departments of Biostatistics, Medicine, and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Grace C. John-Stewart
- Departments of Biostatistics, Medicine, and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Marie Reilly
- Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden
| | - Tomáš Hanke
- Departments of Biostatistics, Medicine, and Epidemiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| | - Katie L. Flanagan
- Vaccinology Theme, Medical Research Council Unit, Fajara, The Gambia
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Feasibility and safety of ALVAC-HIV vCP1521 vaccine in HIV-exposed infants in Uganda: results from the first HIV vaccine trial in infants in Africa. J Acquir Immune Defic Syndr 2013; 63:1-8. [PMID: 23221981 DOI: 10.1097/qai.0b013e31827f1c2d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The development of a safe and effective vaccine against HIV type 1 for the prevention of mother-to-child transmission of HIV would significantly advance the goal of eliminating HIV infection in children. Safety and feasibility results from phase 1, randomized, double-blind, placebo-controlled trial of ALVAC-HIV vCP1521 in infants born to HIV type 1-infected women in Uganda are reported. METHODS HIV-exposed infants were enrolled at birth and randomized (4:1) to receive vaccine or saline placebo intramuscular injections at birth, 4, 8, and 12 weeks of age. Vaccine reactogenicity was assessed at vaccination and days 1 and 2 postvaccination. Infants were followed until 24 months of age. HIV infection status was determined by HIV DNA polymerase chain reaction. RESULTS From October 2006 to May 2007, 60 infants (48 vaccine and 12 placebo) were enrolled with 98% retention at 24 months. One infant was withdrawn, but there were no missed visits or vaccinations among the 59 infants retained. Immune responses elicited by diphtheria, polio, hepatitis B, haemophilus influenzae type B, and measles vaccination were similar in the 2 arms. The vaccine was well tolerated with no severe or life-threatening reactogenicity events. Adverse events were equally distributed across both study arms. Four infants were diagnosed as HIV infected [3 at birth (2 vaccine and 1 placebo) and 1 in vaccine arm at 2 weeks of age]. CONCLUSION The ALVAC-HIV vCP1521 vaccination was feasible and safe in infants born to HIV-infected women in Uganda. The conduct of high-quality infant HIV vaccine trials is achievable in Africa.
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Fouda GG, Mahlokozera T, Salazar-Gonzalez JF, Salazar MG, Learn G, Kumar SB, Dennison SM, Russell E, Rizzolo K, Jaeger F, Cai F, Vandergrift NA, Gao F, Hahn B, Shaw GM, Ochsenbauer C, Swanstrom R, Meshnick S, Mwapasa V, Kalilani L, Fiscus S, Montefiori D, Haynes B, Kwiek J, Alam SM, Permar SR. Postnatally-transmitted HIV-1 Envelope variants have similar neutralization-sensitivity and function to that of nontransmitted breast milk variants. Retrovirology 2013; 10:3. [PMID: 23305422 PMCID: PMC3564832 DOI: 10.1186/1742-4690-10-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 12/21/2012] [Indexed: 11/11/2022] Open
Abstract
Background Breastfeeding is a leading cause of infant HIV-1 infection in the developing world, yet only a minority of infants exposed to HIV-1 via breastfeeding become infected. As a genetic bottleneck severely restricts the number of postnatally-transmitted variants, genetic or phenotypic properties of the virus Envelope (Env) could be important for the establishment of infant infection. We examined the efficiency of virologic functions required for initiation of infection in the gastrointestinal tract and the neutralization sensitivity of HIV-1 Env variants isolated from milk of three postnatally-transmitting mothers (n=13 viruses), five clinically-matched nontransmitting mothers (n=16 viruses), and seven postnatally-infected infants (n = 7 postnatally-transmitted/founder (T/F) viruses). Results There was no difference in the efficiency of epithelial cell interactions between Env virus variants from the breast milk of transmitting and nontransmitting mothers. Moreover, there was similar efficiency of DC-mediated trans-infection, CCR5-usage, target cell fusion, and infectivity between HIV-1 Env-pseudoviruses from nontransmitting mothers and postnatal T/F viruses. Milk Env-pseudoviruses were generally sensitive to neutralization by autologous maternal plasma and resistant to breast milk neutralization. Infant T/F Env-pseudoviruses were equally sensitive to neutralization by broadly-neutralizing monoclonal and polyclonal antibodies as compared to nontransmitted breast milk Env variants. Conclusion Postnatally-T/F Env variants do not appear to possess a superior ability to interact with and cross a mucosal barrier or an exceptional resistance to neutralization that define their capability to initiate infection across the infant gastrointestinal tract in the setting of preexisting maternal antibodies.
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Affiliation(s)
- Genevieve G Fouda
- Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA
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Developing a neonatal HIV vaccine: insights from macaque models of pediatric HIV/AIDS. Curr Opin HIV AIDS 2012; 2:367-74. [PMID: 19372914 DOI: 10.1097/coh.0b013e3282cecf21] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW This review analyzes recent findings from nonhuman primate models of HIV/AIDS that are most relevant to developing active neonatal vaccine strategies against HIV breast milk transmission. We focus on studies published from 2005 to early 2007 that have characterized simian immunodeficiency virus or simian/human immunodeficiency virus transmission and the efficacy of HIV vaccine strategies in neonatal macaques. RECENT FINDINGS Nonhuman primate models of natural HIV breast milk transmission recapitulate many features of infection in human infants; however, the variation in timing and overall low rate of infection in these models precludes their use in conducting vaccine studies. Oral inoculation of infant macaques with defined viral inocula results in reliable transmission and is an efficient model for evaluating neonatal HIV vaccine strategies. All HIV vaccine strategies tested in neonatal macaques are immunogenic, but only a subset of these vaccines confer significant protection against virus acquisition or simian AIDS after oral challenge. SUMMARY Candidate HIV vaccine strategies can elicit virus-specific humoral and cell-mediated immune responses in newborn primates; however, vaccine immunogenicity in infant macaques is not a reliable criterion for predicting a vaccine's efficacy against oral virus challenge exposure.
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30
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Abstract
PURPOSE OF REVIEW This review outlines data available on HIV immunization for the interruption of mother-to-child transmission of HIV. There is a critical need for low cost, safe, and universally accessible methods to interrupt mother-to-child transmission of HIV in utero, intrapartum and though breastfeeding including when the mother acquires HIV infection while breastfeeding her child. Active immunization is the only strategy with this potential. RECENT FINDINGS There are recent findings in three major areas: studies in neonatal macaques, demonstrating encouraging results in terms of providing partial protection from repeat oral SIV and SHIV challenge with active or passive immunization but limited immunologic correlates of protection; safety and immunogenicity of three different canarypox HIV vaccine constructs with and without gp120 envelope subunit boost in infants and studies evaluating the importance of neutralizing antibody in mother-to-child transmission of HIV. SUMMARY To protect infants born to HIV-infected women completely an effective prophylactic vaccine is critical. Candidate vaccines tested in this population to date demonstrate safety, tolerability and immunogenicity. Based on the ongoing risk of infection and the tremendous potential for benefit, further studies of candidate vaccines should proceed in this population.
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Abstract
PURPOSE OF REVIEW The major target groups for an HIV vaccine include breastfeeding infants and adolescents. Differential immune maturity in these age groups may significantly impact vaccine efficacy, and should be taken into account when developing vaccines. Here we review these differences, with an emphasis on the immune response to vaccines for HIV and other pathogens. Recommendations for potential adaptation of current HIV vaccines are also made. RECENT FINDINGS An effective neonatal vaccine needs to be immunogenic in the presence of maternal antibody, and must induce cytotoxic T-lymphocyte responses, neutralizing antibody responses, both systemic and mucosal. There is renewed hope in the possibility of stimulating neutralizing antibodies with HIV vaccination. DNA vaccines are promising for neonates, but will need appropriate boosting. Certain adjuvants and vector delivery systems are more suitable for neonates. Adolescents may have stronger immune responses to HIV vaccines than adults, and will also require induction of mucosal neutralizing humoral and cellular immunity. SUMMARY Some current HIV vaccine strategies may need adaptation for neonates and suitable product development should be accelerated. Vaccines could induce better responses in adolescents and therefore should not be discarded prematurely. Development of vaccines that have potential for these age groups is an urgent global priority.
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Saubi N, Mbewe-Mvula A, Gea-Mallorqui E, Rosario M, Gatell JM, Hanke T, Joseph J. Pre-clinical development of BCG.HIVA(CAT), an antibiotic-free selection strain, for HIV-TB pediatric vaccine vectored by lysine auxotroph of BCG. PLoS One 2012; 7:e42559. [PMID: 22927933 PMCID: PMC3424164 DOI: 10.1371/journal.pone.0042559] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/09/2012] [Indexed: 01/13/2023] Open
Abstract
In the past, we proposed to develop a heterologous recombinant BCG prime-recombinant modified vaccinia virus Ankara (MVA) boost dual pediatric vaccine platform against transmission of breast milk HIV-1 and Mycobacterium tuberculosis (Mtb). In this study, we assembled an E. coli-mycobacterial shuttle plasmid pJH222.HIVACAT expressing HIV-1 clade A immunogen HIVA. This shuttle vector employs an antibiotic resistance-free mechanism based on Operator-Repressor Titration (ORT) system for plasmid selection and maintenance in E. coli and lysine complementation in mycobacteria. This shuttle plasmid was electroporated into parental lysine auxotroph (safer) strain of BCG to generate vaccine BCG.HIVACAT. All procedures complied with Good Laboratory Practices (GLPs). We demonstrated that the episomal plasmid pJH222.HIVACAT was stable in vivo over a 20-week period, and genetically and phenotypically characterized the BCG.HIVACAT vaccine strain. The BCG.HIVACAT vaccine in combination with MVA.HIVA induced HIV-1- and Mtb-specific interferon γ-producing T-cell responses in newborn and adult BALB/c mice. On the other hand, when adult mice were primed with BCG.HIVACAT and boosted with MVA.HIVA.85A, HIV-1-specific CD8+ T-cells producing IFN-γ, TNF-α, IL-2 and CD107a were induced. To assess the biosafety profile of BCG.HIVACAT-MVA.HIVA regimen, body mass loss of newborn mice was monitored regularly throughout the vaccination experiment and no difference was observed between the vaccinated and naïve groups of animals. Thus, we demonstrated T-cell immunogenicity of a novel, safer, GLP-compatible BCG-vectored vaccine using prototype immunogen HIVA. Second generation immunogens derived from HIV-1 as well as other major pediatric pathogens can be constructed in a similar fashion to prime protective responses soon after birth.
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Affiliation(s)
- Narcís Saubi
- AIDS Research Group, Hospital Clinic/IDIBAPS-HIVACAT, School of Medicine, University of Barcelona, Barcelona, Spain
| | | | - Ester Gea-Mallorqui
- AIDS Research Group, Hospital Clinic/IDIBAPS-HIVACAT, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Maximillian Rosario
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Josep Maria Gatell
- AIDS Research Group, Hospital Clinic/IDIBAPS-HIVACAT, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Tomáš Hanke
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Joan Joseph
- AIDS Research Group, Hospital Clinic/IDIBAPS-HIVACAT, School of Medicine, University of Barcelona, Barcelona, Spain
- * E-mail:
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Accelerated heterologous adenovirus prime-boost SIV vaccine in neonatal rhesus monkeys. J Virol 2012; 86:7829-35. [PMID: 22593160 DOI: 10.1128/jvi.00512-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A pediatric human immunodeficiency virus type 1 (HIV-1) vaccine would be desirable to protect infants against HIV-1 transmission from breast-feeding. Such a vaccine would need to induce protective immunity at mucosal surfaces in neonates as soon as possible after birth. Recombinant adenovirus (rAd) vectors have been shown to elicit potent systemic and mucosal virus-specific immune responses in adult nonhuman primates and humans, but these vectors have not previously been comprehensively studied in infants. In this study, we demonstrate that a single injection of rAd26 encoding simian immunodeficiency virus mac239 (SIVmac239) Gag on the day of birth elicited detectable Gag-specific cellular immune responses in rhesus monkeys, but these responses were transient and waned quickly. In contrast, an accelerated heterologous prime-boost regimen involving administration of rAd35 at birth and rAd26 at 4 weeks of life elicited potent and durable Gag-specific cellular and humoral immune responses in neonatal rhesus monkeys, including mucosal responses that remained detectable at 1 year of age. These results suggest the potential of an accelerated heterologous rAd prime-boost regimen as a candidate HIV-1 vaccine for newborns.
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34
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Lohman-Payne B, Slyker J, Rowland-Jones SL. Immune approaches for the prevention of breast milk transmission of HIV-1. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 743:185-95. [PMID: 22454350 DOI: 10.1007/978-1-4614-2251-8_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Barbara Lohman-Payne
- Department of Pediatrics and Child Health, University of Nairobi, Nairobi, Kenya, 00202.
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35
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Prevention of mother-to-child HIV-1 transmission--why we still need a preventive HIV immunization strategy. J Acquir Immune Defic Syndr 2011; 58:359-62. [PMID: 21909031 DOI: 10.1097/qai.0b013e318235517e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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36
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Rigato PO, Fusaro AE, Victor JR, Sato MN. Maternal immunization to modulate the development of allergic response and pathogen infections. Immunotherapy 2011; 1:141-56. [PMID: 20635979 DOI: 10.2217/1750743x.1.1.141] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This article reviews recent experimental approaches of preventive strategies regarding allergy and infections by pathogens, particularly in early childhood, by targeting maternal immunomodulation. Basic research is essential to understand maternal vaccination as a strategy to control allergic disease and bacterial and viral infections; thus, providing support for future translational research. The environmental stimuli and host genetic factors, along with maternal influences in early life when immune systems are developing and during postnatal life, are essential for the decision between tolerance induction or allergen sensitization. Maternal immunomodulation strategies should serve as a challenge when attempting to halt the spread of allergy responses and viral infections, until the innate and adaptive arms of the immune system of the neonates are competent.
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Affiliation(s)
- Paula Ordonhez Rigato
- Laboratório de Dermatologia e Imunodeficiências - LIM56, Faculdade de Medicina da Universidade de São Paulo, Instituto de Medicina Tropical - Prédio II, Av Dr Enéas de Carvalho Aguiar, 500, 3 masculine andar, 05403-05000, São Paulo, Brazil
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Immune-based approaches to the prevention of mother-to-child transmission of HIV-1: active and passive immunization. Clin Perinatol 2010; 37:787-805, ix. [PMID: 21078451 PMCID: PMC2998888 DOI: 10.1016/j.clp.2010.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Despite more than 2 decades of research, an effective vaccine that can prevent HIV-1 infection in populations exposed to the virus remains elusive. In the pursuit of an HIV-1 vaccine, does prevention of exposure to maternal HIV-1 in utero, at birth or in early life through breast milk require special consideration? This article reviews what is known about the immune mechanisms of susceptibility and resistance to mother-to-child transmission (MTCT) of HIV-1 and summarizes studies that have used passive or active immunization strategies to interrupt MTCT of HIV-1. Potentially modifiable infectious cofactors that may enhance transmission and/or disease progression (especially in the developing world) are described. An effective prophylactic vaccine against HIV-1 infection needs to be deployed as part of the Extended Program of Immunization recommended by the World Health Organization for use in developing countries, so it is important to understand how the infant immune system responds to HIV-1 antigens, both in natural infection and presented by candidate vaccines.
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38
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Abstract
PURPOSE OF REVIEW Major roadblocks persist in the development of vaccines that elicit potent neutralizing antibodies targeting diverse HIV-1 strains, similar to known broadly neutralizing HIV-1 human monoclonal antibodies. Alternatively, other types of anti-HIV-1 envelope antibodies that may not neutralize HIV-1 in traditional neutralization assays but have other anti-HIV-1 activities (hereafter termed HIV-1 inhibitory antibodies) can be elicited by current vaccine strategies, and numerous studies are exploring their roles in preventing HIV-1 acquisition. We review examples of strategies for eliciting potentially protective HIV-1 inhibitory antibodies. RECENT FINDINGS Heterologous prime-boost strategies can yield anti-HIV immune responses, although only one (canarypox prime, Env protein boost) has been tested and shown positive results in an efficacy trial (RV144). Although the immune correlates of protection are as yet undefined, the reduced rate of acquisition without a significant effect on initial viral loads or CD4 T-cell counts, have raised the hypothesis of an RV144 vaccine-elicited transient protective B-cell response. SUMMARY In light of the RV144 trial, there is a critical need to define the entire functional spectrum of anti-HIV-1 antibodies, how easily each can be elicited, and how effective different types of antibody effector mechanisms can be in prevention of HIV-1 transmission.
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Affiliation(s)
- Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA.
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Recombinant pro-apoptotic Mycobacterium tuberculosis generates CD8+ T cell responses against human immunodeficiency virus type 1 Env and M. tuberculosis in neonatal mice. Vaccine 2009; 28:152-61. [PMID: 19808028 DOI: 10.1016/j.vaccine.2009.09.087] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 07/29/2009] [Accepted: 09/23/2009] [Indexed: 12/18/2022]
Abstract
Mycobacterium bovis BCG is an attractive vaccine vector against breast milk HIV transmission because it elicits Th1-type responses in newborns. However, BCG causes disease in HIV-infected infants. Genetically attenuated Mycobacterium tuberculosis (Mtb) mutants represent a safer alternative for immunocompromised populations. In the current study, we compared the immunogenicity in mice of three different recombinant attenuated Mtb strains expressing an HIV envelope (Env) antigen construct. Two of these strains (DeltalysA DeltapanCD Mtb and DeltaRD1 DeltapanCD Mtb) failed to induce significant levels of HIV Env-specific CD8(+) T cell responses. In striking contrast, an HIV-1 Env-expressing attenuated DeltalysA Mtb containing a deletion in secA2, which encodes a virulence-related secretion system involved in evading adaptive immunity, generated consistently measurable Env-specific CD8(+) T cell responses that were significantly greater than those observed after immunization with BCG expressing HIV Env. Similarly, another strain of DeltalysA DeltasecA2 Mtb expressing SIV Gag induced Gag- and Mtb-specific CD8(+) T cells producing perforin or IFNgamma, and Gag-specific CD4(+) T cells producing IFNgamma within 3 weeks after immunization in adult mice; in addition, IFNgamma-producing Gag-specific CD8(+) T cells and Mtb-specific CD4(+) T cells were observed in neonatal mice within 1 week of immunization. We conclude that DeltalysA DeltasecA2 Mtb is a promising vaccine platform to construct a safe combination HIV-TB vaccine for use in neonates.
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Ersching J, Pinto AR. HIV-1 vaccine clinical trials: the Brazilian experience. Rev Med Virol 2009; 19:301-11. [DOI: 10.1002/rmv.625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pala P, Gomez-Roman VR, Gilmour J, Kaleebu P. An African perspective on mucosal immunity and HIV-1. Mucosal Immunol 2009; 2:300-14. [PMID: 19421180 DOI: 10.1038/mi.2009.23] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
HIV prevention mandates an understanding of the mechanisms of mucosal immunity with attention to some unique features of the epidemic and mucosal environment in the developing world. An effective vaccine will have to induce mucosal protection against a highly diverse virus, which is equipped with a number of immune evasion strategies. Its development will require assessment of mucosal immune responses, and it will have to protect a mucosal environment where inflammation and altered immune responses are common because of the presence of other mucosal infections, such as sexually transmitted infections and parasites, and where nutritional status may also be compromised. Ideally, not only prevention methods would protect adults but also provide cover against gastrointestinal transmission through maternal milk. Prevention might also be complemented by microbicides and circumcision, two alternative approaches to mucosal protection. It seems unlikely that a single solution will work in all instances and intervention might have to act at multiple levels and be tailored to local circumstances. We review here some of the mucosal events associated with HIV infection that are most relevant in an African setting.
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Affiliation(s)
- P Pala
- Medical Research Council-Uganda Virus Research Institute, Entebbe, Uganda
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Abel K. The rhesus macaque pediatric SIV infection model - a valuable tool in understanding infant HIV-1 pathogenesis and for designing pediatric HIV-1 prevention strategies. Curr HIV Res 2009; 7:2-11. [PMID: 19149549 DOI: 10.2174/157016209787048528] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Worldwide, the AIDS pandemic continues almost relentlessly. Women are now representing the fastest growing group of newly infected HIV-1 infected patients. The risk of mother-to-child-transmission (MTCT) of HIV-1 increases proportionally as many of these women are of childbearing age. The screening of pregnant women, the early diagnosis of HIV-1 infection, and the administration of antiretroviral therapy (ART) have helped to reduce MTCT significantly. However, this holds true only for developed countries. In many resource-poor countries, access to ART is limited, and breastfeeding, a major route of HIV-1 transmission, is essential to protect the infant from other infectious diseases preponderant in those geographic regions. HIV-1 infected children, in contrast to adult patients, have higher levels of virus replication that decline only slowly, and a subset progresses to AIDS within the first two years. Thus, it is imperative to understand pediatric HIV-1 pathogenesis to design effective prevention strategies and/or a successful pediatric HIV-1 vaccine. The review summarizes how MTCT of HIV-1 in humans can be modeled in the infant macaque model of SIV infection. Importantly, the infant macaque model of SIV infection provides the opportunity to study early virus-host interactions in multiple anatomic compartments. Furthermore, the review underlines the importance of evaluating SIV/HIV immune responses in the context of the normal developmental changes the immune system undergoes in the newborn. Thus, the pediatric SIV infection model provides a unique resource for preclinical studies of novel intervention therapies and vaccine strategies to stop MTCT of HIV-1.
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Affiliation(s)
- Kristina Abel
- California National Primate Research Center, and Department of Internal Medicine, Division of Infectious Diseases, School of Medicine, University of California Davis, CA, USA.
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Bråve A, Johansen K, Palma P, Benthin R, Hinkula J. Maternal immune status influences HIV-specific immune responses in pups after DNA prime protein boost using mucosal adjuvant. Vaccine 2008; 26:5957-66. [DOI: 10.1016/j.vaccine.2008.08.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 08/05/2008] [Accepted: 08/31/2008] [Indexed: 11/29/2022]
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Borkowsky W, Yogev R, Muresan P, McFarland E, Frenkel L, Fenton T, Capparelli E, Moye J, Harding P, Ellis N, Heckman B, Kraimer J. Planned multiple exposures to autologous virus in HIV type 1-infected pediatric populations increases HIV-specific immunity and reduces HIV viremia. AIDS Res Hum Retroviruses 2008; 24:401-11. [PMID: 18327977 DOI: 10.1089/aid.2007.0110] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We tested to determine if planned multiple exposures to autologous HIV in pediatric patients with HIV-1 infection will induce cellular immunity that controls viremia. A prospective multicenter study of aviremic pediatric patients on highly active antiretroviral therapy who underwent progressively longer antiretroviral treatment interruptions in cycles starting with 3 days, increasing by 2 days in length each consecutive cycle, was conducted. Eight individuals became viremic and reached Cycle 13 or greater with an "off-therapy" interval of >or=27 days. HIV-specific interferon-gamma (IFN-gamma) production to inactivated HIV and vaccinia vectors expressing gag, env, nef, and pol increased (>10-fold) from baseline in six of eight subjects. The HIV-specific lymphoproliferative response as measured by the median stimulation index (SI) increased in the treatment group from 1 at baseline to 16, 12, 4, and 3 at Cycles 7, 10, 13, and 17, respectively. Median plasma RNA levels peaked at Cycle 7 (4.45 log) and declined to levels <10(4) cp/ml after Cycle 10 (4.1, 3.5, and 3.4 at Cycles 10, 13, and 17). In a subset of five patients who reached Cycle 17, HIV-specific IFN-gamma frequencies were 4- to 30-fold higher and median RNA levels were 0.32-2.10 (median 1.3) log lower than at comparable days off treatment at Cycle 8 (17 days off therapy). A second group of children, not undergoing drug interruption, did not develop significant increases in either HIV-specific IFN-gamma production or SI. Increased HIV-specific immune responses and decreased HIV RNA were seen in those children who have had >10 cycles of antiretroviral discontinuations of increasing durations acting as autologous virus vaccinations. Other studies may have failed due to an insufficient number of exposures to HIV; most of the studies had fewer than six drug interruptions.
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Affiliation(s)
| | - Ram Yogev
- Chicago Children's Memorial Hospital, Chicago, Illinois 60614
| | | | | | - Lisa Frenkel
- University of Washington, Seattle, Washington 98103
| | - Terry Fenton
- FSTRF-Harvard School of Public Health, Boston, Massachusetts 02115
| | | | | | - Paul Harding
- University of Colorado Health Sciences Center, Denver, Colorado 80045
| | - Nina Ellis
- University of Washington, Seattle, Washington 98103
| | - Barbara Heckman
- Frontier Science & Technology Research Foundation–Data Management Center, Amherst, New York 14226
| | - Joyce Kraimer
- Social & Scientific Systems, Inc., Silver Springs, Maryland 20910
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Lehman DA, Farquhar C. Biological mechanisms of vertical human immunodeficiency virus (HIV-1) transmission. Rev Med Virol 2007; 17:381-403. [PMID: 17542053 DOI: 10.1002/rmv.543] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the absence of interventions, 30-45% of exposed infants acquire human immunodeficiency virus type 1 (HIV-1) through mother-to-child transmission. It remains unclear why some infants become infected while others do not, despite significant exposure to HIV-1 in utero, during delivery and while breastfeeding. Here we discuss the correlates of vertical transmission with an emphasis on factors that increase maternal HIV-1 levels, either systemically or locally in genital secretions and breast milk. Immune responses may influence maternal viral load, and data suggest that maternal neutralising antibodies reduce infection rates. In addition, infants may be capable of mounting HIV-specific cellular immune responses. We propose that both humoral and cellular responses are necessary to reduce infection because cell-free as well as cell-associated virus appears to play a role in vertical transmission. These distinct forms of the virus may be targeted most effectively by different components of the immune system. We also discuss the use of antiretrovirals to reduce transmission, focusing on the mechanisms of action of regimens currently used in developing country settings. We conclude that prevention relies not only on reducing maternal HIV-1 levels within blood, genital tract and breast milk, but also on pre- and/or post-exposure prophylaxis to the infant. However, HIV-1 has the capacity to mutate under drug pressure and rapidly acquires mutations conferring antiretroviral resistance. This review concludes with data on persistence of low-level resistance after delivery as well as recent guidelines for maternal and infant regimens designed to limit resistance.
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Affiliation(s)
- Dara A Lehman
- Department of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
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