1
|
Johnson AMF, Hager K, Alameh MG, Van P, Potchen N, Mayer-Blackwell K, Fiore-Gartland A, Minot S, Lin PJC, Tam YK, Weissman D, Kublin JG. The Regulation of Nucleic Acid Vaccine Responses by the Microbiome. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:1680-1692. [PMID: 37850965 PMCID: PMC10656434 DOI: 10.4049/jimmunol.2300196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 09/19/2023] [Indexed: 10/19/2023]
Abstract
Nucleic acid vaccines, including both RNA and DNA platforms, are key technologies that have considerable promise in combating both infectious disease and cancer. However, little is known about the extrinsic factors that regulate nucleic acid vaccine responses and which may determine their effectiveness. The microbiome is recognized as a significant regulator of immune development and response, whose role in regulating some traditional vaccine platforms has recently been discovered. Using germ-free and specific pathogen-free mouse models in combination with different protein, DNA, and mRNA vaccine regimens, we demonstrate that the microbiome is a significant regulator of nucleic acid vaccine immunogenicity. Although the presence of the microbiome enhances CD8+ T cell responses to mRNA lipid nanoparticle immunization, the microbiome suppresses Ig and CD4+ T cell responses to DNA-prime, DNA-protein-boost immunization, indicating contrasting roles for the microbiome in the regulation of these different nucleic acid vaccine platforms. In the case of mRNA lipid nanoparticle vaccination, germ-free mice display reduced dendritic cell/macrophage activation that may underlie the deficient vaccine response. Our study identifies the microbiome as a relevant determinant of nucleic acid vaccine response with implications for continued therapeutic development and deployment of these vaccines.
Collapse
Affiliation(s)
- Andrew M. F. Johnson
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| | - Kevin Hager
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| | | | - Phuong Van
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| | - Nicole Potchen
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| | | | | | - Samuel Minot
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| | | | | | - Drew Weissman
- Penn Institute for RNA Innovation, University of Pennsylvania, Philadelphia, PA
| | - James G. Kublin
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA
| |
Collapse
|
2
|
Johnson AMF, Hager K, Alameh MG, Van P, Potchen N, Mayer-Blackwell K, Fiore-Gartland A, Minot S, Lin PJC, Tam YK, Weissman D, Kublin JG. The Regulation of Nucleic Acid Vaccine Responses by the Microbiome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.18.529093. [PMID: 36824851 PMCID: PMC9949122 DOI: 10.1101/2023.02.18.529093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Nucleic acid vaccines, including both RNA and DNA platforms, are key technologies that have considerable promise in combating both infectious disease and cancer. However, little is known about the extrinsic factors that regulate nucleic acid vaccine responses and which may determine their effectiveness. The microbiome is recognized as a significant regulator of immune development and response, whose role in regulating some traditional vaccine platforms has recently been discovered. Using germ-free and specific-pathogen-free mouse models in combination with different protein, DNA, and mRNA vaccine regimens, we demonstrate that the microbiome is a significant regulator of nucleic acid vaccine immunogenicity. While the presence of the microbiome enhances CD8+ T cell responses to mRNA lipid nanoparticle (LNP) immunization, the microbiome suppresses immunoglobulin and CD4+ T cell responses to DNA-prime, DNA-protein-boost immunization, indicating contrasting roles for the microbiome in the regulation of these different nucleic acid vaccine platforms. In the case of mRNA-LNP vaccination, germ-free mice display reduced dendritic cell/macrophage activation that may underlie the deficient vaccine response. Our study identifies the microbiome as a relevant determinant of nucleic acid vaccine response with implications for their continued therapeutic development and deployment.
Collapse
|
3
|
Hanass-Hancock J, Carpenter B, Reddy T, Nzuza A, Gaffoor Z, Goga A, Andrasik M. Participants' characteristics and motivations to screen for HIV vaccine and monoclonal antibody trials in KwaZulu-Natal, South Africa. Trials 2021; 22:897. [PMID: 34895272 PMCID: PMC8665490 DOI: 10.1186/s13063-021-05792-7] [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: 07/02/2020] [Accepted: 11/03/2021] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND HIV is one of the greatest public health challenges in South Africa. Potential HIV vaccines and antibodies are thought to be cost-effective biomedical HIV prevention methods and are currently under investigation in phase I, II, and III trials. Consequently, current and future clinical trials need to ensure sufficient recruitment and retention. To achieve this goal, clinical trial staff need to understand the socio-demographic and behavioural characteristics of people volunteering to screen for these trials and their reasons for volunteering. METHODS We conducted a secondary analysis of participant screening data across five vaccine and monoclonal antibody trials at four sites in KwaZulu-Natal, South Africa. Our study reviewed the demographic, behavioural, motivational, and health-related data from the case report forms and screening questionnaires. Descriptive statistics, chi-squared, and one-way ANOVA tests were used to analyse participants' characteristics and motivation to participate in HIV vaccine and monoclonal antibody trials. Analyses were conducted using R version 3.5.2. RESULTS Screening data from 1934 participants, including 79.2% of women, were obtained across all five trials (1034 enrolled, 900 screened out/declined). Screened participants predominately self-identified as black, heterosexual, cisgender women or men, many with lower educational backgrounds (43.9% did not complete secondary/high school), and several self-reported HIV-risk behaviours among themselves and their partners. 10.8% of the screened participants were living with HIV. Avoiding HIV risk was the main motivation to participate in clinical trials, followed by altruistic reasons such as a desire to help the community or helping to find a vaccine. DISCUSSION The current recruitment approach of these trials attracts heterosexual participants who seek to reduce HIV risk and support their community. Hence, the data suggest the need for and potential acceptance of continued ongoing HIV prevention efforts. Current trials attract participants with lower educational levels, which may be driven by the site locations, current community mobilisation strategies and research site opening hours. The sites could consider more flexible working hours to accommodate working participants and find ways to connect participants to educational support and opportunities to upgrade education levels for the current clientele. TRIAL REGISTRATION HVTN 100: A Safety and Immune Response Study of 2 Experimental HIV Vaccines, NCT02404311 . Registered on March 17, 2015. HVTN 111: Safety and Immune Response to a Clade C DNA HIV Vaccine, NCT02997969. Registered on December 16, 2016. HVTN 108: Evaluating the Safety and Immunogenicity of HIV Clade C DNA Vaccine and MF59- or AS01B-Adjuvanted Clade C Env Protein Vaccines in Various Combinations in Healthy, HIV-Uninfected Adults, NCT02915016. Registered on September 22, 2016. HVTN 702: Pivotal Phase 2b/3 ALVAC/Bivalent gp120/MF59 HIV Vaccine Prevention Safety and Efficacy Study in South Africa, NCT02968849. Registered on November 1, 2016. HVTN 703/HPTN 081: Evaluating the Safety and Efficacy of the VRC01 Antibody in Reducing Acquisition of HIV-1 Infection in Women, NCT02568215 . Registered on October 1, 2015.
Collapse
Affiliation(s)
- Jill Hanass-Hancock
- South African Medical Research Council, Gender and Health Research Unit, Cape Town, South Africa. .,University of KwaZulu Natal School of Health Science, Durban, South Africa.
| | - Bradley Carpenter
- South African Medical Research Council, Gender and Health Research Unit, Cape Town, South Africa.,University of KwaZulu Natal School of Health Science, Durban, South Africa
| | - Tarylee Reddy
- South African Medical Research Council, Biostatistics Research Unit, Seattle, USA
| | - Ayanda Nzuza
- South African Medical Research Council, Gender and Health Research Unit, Cape Town, South Africa
| | - Zakir Gaffoor
- South African Medical Research Council, HIV Prevention Research Unit, Seattle, USA
| | - Ameena Goga
- South African Medical Research Council, HIV Prevention Research Unit, Seattle, USA
| | - Michele Andrasik
- HIV Vaccine Trials Network, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA
| |
Collapse
|
4
|
Hokello J, Sharma AL, Tyagi M. An Update on the HIV DNA Vaccine Strategy. Vaccines (Basel) 2021; 9:vaccines9060605. [PMID: 34198789 PMCID: PMC8226902 DOI: 10.3390/vaccines9060605] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/26/2021] [Accepted: 06/01/2021] [Indexed: 01/24/2023] Open
Abstract
In 2020, the global prevalence of human immunodeficiency virus (HIV) infection was estimated to be 38 million, and a total of 690,000 people died from acquired immunodeficiency syndrome (AIDS)–related complications. Notably, around 12.6 million people living with HIIV/AIDS did not have access to life-saving treatment. The advent of the highly active antiretroviral therapy (HAART) in the mid-1990s remarkably enhanced the life expectancy of people living with HIV/AIDS as a result of improved immune functions. However, HAART has several drawbacks, especially when it is not used properly, including a high risk for the development of drug resistance, as well as undesirable side effects such as lipodystrophy and endocrine dysfunctions, which result in HAART intolerability. HAART is also not curative. Furthermore, new HIV infections continue to occur globally at a high rate, with an estimated 1.7 million new infections occurring in 2018 alone. Therefore, there is still an urgent need for an affordable, effective, and readily available preventive vaccine against HIV/AIDS. Despite this urgent need, however, progress toward an effective HIV vaccine has been modest over the last four decades. Reasons for this slow progress are mainly associated with the unique aspects of HIV itself and its ability to rapidly mutate, targeting immune cells and escape host immune responses. Several approaches to an HIV vaccine have been undertaken. However, this review will mainly discuss progress made, including the pre-clinical and clinical trials involving vector-based HIV DNA vaccines and the use of integrating lentiviral vectors in HIV vaccine development. We concluded by recommending particularly the use of integrase-defective lentiviral vectors, owing to their safety profiles, as one of the promising vectors in HIV DNA vaccine strategies both for prophylactic and therapeutic HIV vaccines.
Collapse
Affiliation(s)
- Joseph Hokello
- Department of Microbiology and Immunology, Faculty of Biomedical Sciences, Kampala International University-Western Campus, P.O. Box 71, Bushenyi 0256, Uganda;
| | | | - Mudit Tyagi
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA;
- Correspondence:
| |
Collapse
|
5
|
Research productivity and collaboration of the NIH-funded HIV vaccine trials network: A bibliometric analysis. Heliyon 2021; 7:e06005. [PMID: 33532641 PMCID: PMC7829147 DOI: 10.1016/j.heliyon.2021.e06005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 12/04/2020] [Accepted: 01/13/2021] [Indexed: 12/31/2022] Open
Abstract
The HIV Vaccine Trials Network (HVTN) is the world's largest publicly funded, multi-disciplinary international collaboration facilitating the development of vaccines to prevent HIV/AIDS and has conducted the vast majority of HIV/AIDS clinical trials since its inception in 1999. Although scientific findings from the program have been published in scholarly journals, the impact of a large scientific research network such as the HVTN on the HIV/AIDS vaccine field has not been assessed. This paper describes and elucidates the productivity, influence, and collaboration among HVTN researchers over the last two decades. Our analyses indicate that the HVTN has funded a large number of HIV/AIDS vaccine safety and efficacy clinical trials through a strong global network of clinical sites. In addition, several metrics indicate HVTN researchers also published original research articles that are influential in the HIV vaccine field. Scientific research collaboration is critically important in a complex and multidisciplinary field such as HIV vaccine development as it allows improved sharing of knowledge and expertise as well as the pooling of resources and data. We found that collaboration in the HIV vaccine field increased during this time period and collaboration among HVTN authors increased even more. Combining these productivity, influence, and collaboration metrics with research outcomes can provide a comprehensive assessment of large complex programs such as the HVTN.
Collapse
|
6
|
Laher F, Bekker LG, Garrett N, Lazarus EM, Gray GE. Review of preventative HIV vaccine clinical trials in South Africa. Arch Virol 2020; 165:2439-2452. [PMID: 32797338 PMCID: PMC7426202 DOI: 10.1007/s00705-020-04777-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023]
Abstract
New HIV infections continue relentlessly in southern Africa, demonstrating
the need for a vaccine to prevent HIV subtype C. In South Africa, the country with the
highest number of new infections annually, HIV vaccine research has been ongoing since
2003 with collaborative public-private-philanthropic partnerships. So far, 21 clinical
trials have been conducted in South Africa, investigating seven viral vectors, three DNA
plasmids, four envelope proteins, five adjuvants and three monoclonal antibodies. Active
vaccine candidates have spanned subtypes A, B, C, E and multi-subtype mosaic sequences.
All were well tolerated. Four concepts were investigated for efficacy: rAd5-gag/pol/nef
showed increased HIV acquisition in males, subtype C ALVAC/gp120/MF59 showed no
preventative efficacy, and the trials for the VRC01 monoclonal antibody and
Ad26.Mos4.HIV/subtype C gp140/ aluminum phosphate are ongoing. Future trials are planned
with DNA/viral vector plus protein combinations in concert with pre-exposure
prophylaxis, and sequential immunization studies with transmitted/founder HIV envelope
to induce broadly neutralizing antibodies. Finally, passive immunization trials are
underway to build on the experience with VRC01, including single and combination
antibody trials with an antibody derived from a subtype-C-infected South African donor.
Future consideration should be given to the evaluation of novel strategies, for example,
inactivated-whole-virus vaccines.
Collapse
Affiliation(s)
- Fatima Laher
- Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Linda-Gail Bekker
- The Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa
| | - Nigel Garrett
- Centre for the AIDS Programme of Research in South Africa, Durban, South Africa.,Department of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Erica M Lazarus
- Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Glenda E Gray
- Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,South African Medical Research Council, Cape Town, South Africa
| |
Collapse
|
7
|
Singh JA. The Case for Why Africa Should Host COVID-19 Candidate Vaccine Trials. J Infect Dis 2020; 222:351-355. [PMID: 32492144 PMCID: PMC7313920 DOI: 10.1093/infdis/jiaa303] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/27/2020] [Indexed: 01/29/2023] Open
Abstract
In response to provocative comments by 2 European clinicians and scientists, the World Health Organization Director General has declared that Africa will not host COVID-19 vaccine trials. Such a stance risks stigmatizing COVID-19 vaccine trials in Africa and depriving Africa of critical research. To the contrary, there is a critical need for Africa to host COVID-19 vaccine trials on public health, scientific, and ethics grounds.
Collapse
Affiliation(s)
- Jerome Amir Singh
- Centre for the AIDS Programme of Research in South Africa, Durban, South Africa
| |
Collapse
|
8
|
Han JW, Sung PS, Hong SH, Lee H, Koh JY, Lee H, White S, Maslow JN, Weiner DB, Park SH, Jeong M, Heo J, Ahn SH, Shin EC. IFNL3-adjuvanted HCV DNA vaccine reduces regulatory T cell frequency and increases virus-specific T cell responses. J Hepatol 2020; 73:72-83. [PMID: 32088322 DOI: 10.1016/j.jhep.2020.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Although direct-acting antiviral (DAA) treatment results in a sustained virologic response (SVR) in most patients with chronic HCV infection, they are at risk of re-infection. Moreover, the immune system is not completely normalized even after SVR (e.g. increased regulatory T [Treg] cell frequency). We developed a DNA vaccine, GLS-6150, to prevent re-infection of patients with DAA-induced SVR and evaluated its safety and immunogenicity in individuals with chronic HCV infection. METHODS GLS-6150 consists of plasmids encoding HCV non-structural proteins (NS3-NS5A) and adjuvant IFNL3. The vaccine was administered 4 times at 4-weekly intervals to 3 groups (1, 3, or 6 mg/vaccination; n = 6 per group), followed by a 6 mg boost at 24 weeks (n = 14). Peripheral blood T cell responses were evaluated by interferon (IFN)-γ enzyme-linked immunospot assays, intracellular cytokine staining, and major histocompatibility complex class-I (MHC-I) dextramer staining. Treg cell frequency was assessed by flow cytometry. RESULTS Severe adverse events or vaccine discontinuation were not reported. The IFN-γ spot-forming cells specific to NS3-NS5A were increased by GLS-6150. Both CD4+ and CD8+ T cells produced multiple cytokines. However, the frequency and phenotype of HCV-specific MHC-I dextramer+CD8+ T cells were not changed. Interestingly, the frequency of Treg cells, particularly activated Treg cells, was decreased by GLS-6150, as expected from previous reports that IFNL3 adjuvants decrease Treg cell frequency. Ex vivo IFN-λ3 treatment reduced Treg frequency in pre-vaccination peripheral blood mononuclear cells. Finally, Treg cell frequency inversely correlated with HCV-specific, IFN-γ-producing T cell responses in the study participants. CONCLUSIONS We demonstrate that GLS-6150 decreases Treg cell frequency and enhances HCV-specific T cell responses without significant side effects. A phase I clinical trial of GLS-6150 is currently underway in patients with DAA-induced SVR. CLINICAL TRIAL NUMBER NCT02027116. LAY SUMMARY Although direct-acting antivirals (DAAs) are successfully used for the treatment of chronic hepatitis C virus (HCV) infection, a prophylactic HCV vaccine needs to be developed, especially for patients who achieve a sustained virologic response. In the current study, we show that a DNA vaccine (GLS-6150) was safe and increased HCV-specific T cell responses. A clinical trial is underway to test this vaccine in patients with a sustained virologic response following DAA therapy.
Collapse
Affiliation(s)
- Ji Won Han
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Pil Soo Sung
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea; Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Seon-Hui Hong
- Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon 34141, Republic of Korea
| | - Hoyoung Lee
- Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon 34141, Republic of Korea
| | - June Young Koh
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Hyojin Lee
- GeneOne Life Science, Inc., Seoul 06060, Republic of Korea
| | - Scott White
- Inovio Pharmaceuticals, Plymouth Meeting, PA 19462, USA
| | - Joel N Maslow
- GeneOne Life Science, Inc., Seoul 06060, Republic of Korea
| | | | - Su-Hyung Park
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea; Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon 34141, Republic of Korea
| | - Moonsup Jeong
- GeneOne Life Science, Inc., Seoul 06060, Republic of Korea
| | - Jeong Heo
- Department of Internal Medicine, College of Medicine, Pusan National University, Busan 49241, Republic of Korea.
| | - Sang Hoon Ahn
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
| | - Eui-Cheol Shin
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea; Biomedical Science and Engineering Interdisciplinary Program, KAIST, Daejeon 34141, Republic of Korea.
| |
Collapse
|
9
|
Antibody and cellular responses to HIV vaccine regimens with DNA plasmid as compared with ALVAC priming: An analysis of two randomized controlled trials. PLoS Med 2020; 17:e1003117. [PMID: 32442195 PMCID: PMC7244095 DOI: 10.1371/journal.pmed.1003117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 04/23/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND DNA plasmids promise a pragmatic alternative to viral vectors for prime-boost HIV-1 vaccines. We evaluated DNA plasmid versus canarypox virus (ALVAC) primes in 2 randomized, double-blind, placebo-controlled trials in southern Africa with harmonized trial designs. HIV Vaccine Trials Network (HVTN) 111 tested DNA plasmid prime by needle or needleless injection device (Biojector) and DNA plasmid plus gp120 protein plus MF59 adjuvant boost. HVTN 100 tested ALVAC prime and ALVAC plus gp120 protein plus MF59 adjuvant boost (same protein/adjuvant as HVTN 111) by needle. METHODS AND FINDINGS The primary endpoints for this analysis were binding antibody (bAb) responses to HIV antigens (gp120 from strains ZM96, 1086, and TV1; variable 1 and 2 [V1V2] regions of gp120 from strains TV1, 1086, and B.CaseA, as 1086 V1V2 and B.CaseA were correlates of risk in the RV144 efficacy trial), neutralizing antibody (nAb) responses to pseudoviruses TV1c8.2 and MW925.26, and cellular responses to vaccine-matched antigens (envelope [Env] from strains ZM96, 1086, and TV1; and Gag from strains LAI and ZM96) at month 6.5, two weeks after the fourth vaccination. Per-protocol cohorts included vaccine recipients from HVTN 100 (n = 186, 60% male, median age 23 years) enrolled between February 9, 2015, and May 26, 2015 and from HVTN 111 (n = 56, 48% male, median age 24 years) enrolled between June 21, 2016, and July 13, 2017. IgG bAb response rates were 100% to 3 Env gp120 antigens in both trials. Response rates to V1V2 were lower and similar in both trials except to vaccine-matched 1086 V1V2, with rates significantly higher for the DNA-primed regimen than the ALVAC-primed regimen: 96.6% versus 72.7% (difference = 23.9%, 95% CI 15.6%-32.2%, p < 0.001). Among positive responders, bAb net mean fluorescence intensity (MFI) was significantly higher with the DNA-primed regimen than ALVAC-primed for 1086 V1V2 (geometric mean [GM] 2,833.3 versus 1,200.9; ratio = 2.36, 95% CI 1.42-3.92, p < 0.001) and B.CaseA V1V2 (GM 2314.0 versus 744.6, ratio = 3.11, 95% CI 1.51-6.38, p = 0.002). nAb response rates were >98% in both trials, with significantly higher 50% inhibitory dilution (ID50) among DNA-primed positive responders (n = 53) versus ALVAC-primed (n = 182) to tier 1A MW965.26 (GM 577.7 versus 265.7, ratio = 2.17, 95% CI 1.67-2.83, p < 0.001) and to TV1c8.2 (GM 187.3 versus 100.4, ratio = 1.87, 95% CI 1.48-2.35, p < 0.001). CD4+ T-cell response rates were significantly higher with DNA plasmid prime via Biojector than ALVAC prime (91.4% versus 52.8%, difference = 38.6%, 95% CI 20.5%-56.6%, p < 0.001 for ZM96.C; 88.0% versus 43.1%, difference = 44.9%, 95% CI 26.7%-63.1%, p < 0.001 for 1086.C; 55.5% versus 2.2%, difference = 53.3%, 95% CI 23.9%-82.7%, p < 0.001 for Gag LAI/ZM96). The study's main limitations include the nonrandomized comparison of vaccines from 2 different trials, the lack of data on immune responses to other non-vaccine-matched antigens, and the uncertain clinical significance of the observed immunological effects. CONCLUSIONS In this study, we found that further investigation of DNA/protein regimens is warranted given enhanced immunogenicity to the V1V2 correlates of decreased HIV-1 acquisition risk identified in RV144, the only HIV vaccine trial to date to show any efficacy.
Collapse
|