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Steinhagen F, Kinjo T, Bode C, Klinman DM. TLR-based immune adjuvants. Vaccine 2011; 29:3341-55. [PMID: 20713100 PMCID: PMC3000864 DOI: 10.1016/j.vaccine.2010.08.002] [Citation(s) in RCA: 372] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 07/27/2010] [Accepted: 08/01/2010] [Indexed: 12/29/2022]
Abstract
This work describes the nature and strength of the immune response induced by various Toll-like receptor ligands and their ability to act as vaccine adjuvants. It reviews the various ligands capable of triggering individual TLRs, and then focuses on the efficacy and safety of those agents for which clinical results are available.
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Affiliation(s)
- Folkert Steinhagen
- Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, United States
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Abstract
Synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs trigger cells that express Toll-like receptor 9 (including human plasmacytoid dendritic cells and B cells) to mount an innate immune response characterized by the production of Th1 and proinflammatory cytokines. When used as vaccine adjuvants, CpG ODNs improve the function of professional antigen-presenting cells and boost the generation of humoral and cellular vaccine-specific immune responses. These effects are optimized by maintaining ODNs and vaccine in close proximity. The adjuvant properties of CpG ODNs are observed when administered either systemically or mucosally, and persist in immunocompromised hosts. Preclinical studies indicate that CpG ODNs improve the activity of vaccines targeting infectious diseases and cancer. Clinical trials demonstrate that CpG ODNs have a good safety profile and increase the immunogenicity of coadministered vaccines.
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Affiliation(s)
- Christian Bode
- Cancer and Infammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Gan Zhao
- Cancer and Infammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Folkert Steinhagen
- Cancer and Infammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Takeshi Kinjo
- Cancer and Infammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Dennis M Klinman
- Cancer and Infammation Program, National Cancer Institute, Frederick, MD 21702, USA
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Limbach K, Aguiar J, Gowda K, Patterson N, Abot E, Sedegah M, Sacci J, Richie T. Identification of two new protective pre-erythrocytic malaria vaccine antigen candidates. Malar J 2011; 10:65. [PMID: 21410955 PMCID: PMC3073953 DOI: 10.1186/1475-2875-10-65] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 03/16/2011] [Indexed: 11/30/2022] Open
Abstract
Background Despite years of effort, a licensed malaria vaccine is not yet available. One of the obstacles facing the development of a malaria vaccine is the extensive heterogeneity of many of the current malaria vaccine antigens. To counteract this antigenic diversity, an effective malaria vaccine may need to elicit an immune response against multiple malaria antigens, thereby limiting the negative impact of variability in any one antigen. Since most of the malaria vaccine antigens that have been evaluated in people have not elicited a protective immune response, there is a need to identify additional protective antigens. In this study, the efficacy of three pre-erythrocytic stage malaria antigens was evaluated in a Plasmodium yoelii/mouse protection model. Methods Mice were immunized with plasmid DNA and vaccinia virus vectors that expressed one, two or all three P. yoelii vaccine antigens. The immunized mice were challenged with 300 P. yoelii sporozoites and evaluated for subsequent infection. Results Vaccines that expressed any one of the three antigens did not protect a high percentage of mice against a P. yoelii challenge. However, vaccines that expressed all three antigens protected a higher percentage of mice than a vaccine that expressed PyCSP, the most efficacious malaria vaccine antigen. Dissection of the multi-antigen vaccine indicated that protection was primarily associated with two of the three P. yoelii antigens. The protection elicited by a vaccine expressing these two antigens exceeded the sum of the protection elicited by the single antigen vaccines, suggesting a potential synergistic interaction. Conclusions This work identifies two promising malaria vaccine antigen candidates and suggests that a multi-antigen vaccine may be more efficacious than a single antigen vaccine.
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Affiliation(s)
- Keith Limbach
- US Military Malaria Vaccine Program, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, USA.
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Cheng C, Pal S, Bettahi I, Oxford KL, Barry PA, de la Maza LM. Immunogenicity of a vaccine formulated with the Chlamydia trachomatis serovar F, native major outer membrane protein in a nonhuman primate model. Vaccine 2011; 29:3456-64. [PMID: 21376796 DOI: 10.1016/j.vaccine.2011.02.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/16/2011] [Accepted: 02/18/2011] [Indexed: 11/24/2022]
Abstract
To determine the ability of a vaccine formulated with the genital Chlamydia trachomatis, serovar F, native major outer membrane protein (Ct-F-nMOMP), to induce systemic and mucosal immune responses, rhesus macaques (Macaca mulatta) were immunized three times by the intramuscular (i.m.) and subcutaneous (s.c.) routes using CpG-2395 and Montanide ISA 720 VG, as adjuvants. As controls, another group of M. mulatta was immunized with ovalbumin instead of Ct-F-nMOMP using the same formulation and routes. High levels of Chlamydia-specific IgG and IgA antibodies were detected in plasma, vaginal washes, tears, saliva, and stools from the Ct-F-nMOMP immunized animals. Also, high neutralizing antibody titers were detected in the plasma from these animals. Monkeys immunized with ovalbumin had no detectable Chlamydia-specific antibodies. Furthermore, as measured by a lymphoproliferative assay, significant Chlamydia-specific cell-mediated immune responses were detected in the peripheral blood mononuclear cells (PBMC) from the rhesus macaques vaccinated with Ct-F-nMOMP when compared with the animals immunized with ovalbumin. In addition, the levels of two Th1 cytokines, IFN-γ and TNF-α, were significantly higher in the animals immunized with Ct-F-nMOMP when compared with those from the monkeys immunized with ovalbumin. To our knowledge, this is the first time that mucosal and systemic immune responses have been investigated in a nonhuman primate model using a subunit vaccine from a human genital C. trachomatis serovar.
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Affiliation(s)
- Chunmei Cheng
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA
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55
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Miura K, Zhou H, Diouf A, Tullo G, Moretz SE, Aebig JA, Fay MP, Miller LH, Doumbo OK, Sagara I, Dicko A, Long CA, Ellis RD. Immunological responses against Plasmodium falciparum Apical Membrane Antigen 1 vaccines vary depending on the population immunized. Vaccine 2011; 29:2255-61. [PMID: 21277408 DOI: 10.1016/j.vaccine.2011.01.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 12/27/2010] [Accepted: 01/16/2011] [Indexed: 11/24/2022]
Abstract
Clinical development of malaria vaccines progresses from trials in malaria naïve adults to malaria exposed adults followed by malaria exposed children. It is not well known whether immune responses in non-target populations are predictive of those in target populations, particularly in African children. Therefore humoral responses in three different populations (U.S. adults, Malian adults and Malian children) were compared in this study. They were immunized with 80 μg of Apical Membrane Antigen 1 (AMA1)/alhydrogel on days 0 and 28. Sera were collected on days 0 and 42; antibody levels were determined by ELISA and the functionality of antibodies was evaluated by Growth Inhibition Assay. After immunization, there was no significant difference in antibody levels between the Malian children and the Malian adults, but U.S. adults showed lower antibody levels. Vaccination did not significantly change growth-inhibitory activity in Malian adults, but inhibition increased significantly in both U.S. adults and Malian children. Vaccine-induced inhibitory activity was reversed by pre-incubation with AMA1 protein, but pre-existing infection-induced inhibition was not. This study shows that humoral responses elicited by the AMA1 vaccine varied depending on the population, most likely reflecting different levels of previous malaria exposure. Thus predicting immune responses from non-target populations is not desirable.
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Affiliation(s)
- Kazutoyo Miura
- Malaria Vaccine Development Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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56
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Crompton PD, Pierce SK, Miller LH. Advances and challenges in malaria vaccine development. J Clin Invest 2010; 120:4168-78. [PMID: 21123952 DOI: 10.1172/jci44423] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Malaria caused by Plasmodium falciparum remains a major public health threat, especially among children and pregnant women in Africa. An effective malaria vaccine would be a valuable tool to reduce the disease burden and could contribute to elimination of malaria in some regions of the world. Current malaria vaccine candidates are directed against human and mosquito stages of the parasite life cycle, but thus far, relatively few proteins have been studied for potential vaccine development. The most advanced vaccine candidate, RTS,S, conferred partial protection against malaria in phase II clinical trials and is currently being evaluated in a phase III trial in Africa. New vaccine targets need to be identified to improve the chances of developing a highly effective malaria vaccine. A better understanding of the mechanisms of naturally acquired immunity to malaria may lead to insights for vaccine development.
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Affiliation(s)
- Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Disease (NIAID), NIH, Rockville, Maryland, USA
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57
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Ellis RD, Sagara I, Durbin A, Dicko A, Shaffer D, Miller L, Assadou MH, Kone M, Kamate B, Guindo O, Fay MP, Diallo DA, Doumbo OK, Emanuel EJ, Millum J. Comparing the understanding of subjects receiving a candidate malaria vaccine in the United States and Mali. Am J Trop Med Hyg 2010; 83:868-72. [PMID: 20889881 PMCID: PMC2946758 DOI: 10.4269/ajtmh.2010.10-0062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 05/14/2010] [Indexed: 11/07/2022] Open
Abstract
Initial responses to questionnaires used to assess participants' understanding of informed consent for malaria vaccine trials conducted in the United States and Mali were tallied. Total scores were analyzed by age, sex, literacy (if known), and location. Ninety-two percent (92%) of answers by United States participants and 85% of answers by Malian participants were correct. Questions more likely to be answered incorrectly in Mali related to risk, and to the type of vaccine. For adult participants, independent predictors of higher scores were younger age and female sex in the United States, and male sex in Mali. Scores in the United States were higher than in Mali (P = 0.005). Despite this difference participants at both sites were well informed overall. Although interpretation must be qualified because questionnaires were not intended as research tools and were not standardized among sites, these results do not support concerns about systematic low understanding among research participants in developing versus developed countries.
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Affiliation(s)
- Ruth D Ellis
- Malaria Vaccine Development Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20892, USA.
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Goodman AL, Draper SJ. Blood-stage malaria vaccines - recent progress and future challenges. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 104:189-211. [PMID: 20507694 DOI: 10.1179/136485910x12647085215534] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Plasmodium falciparum malaria is a major global health problem, responsible for up to 1 million deaths each year. Major efforts have been made to develop an effective vaccine against this disease, to reduce the associated morbidity and mortality. There has already been considerable progress, with the first vaccine against the pre-erythrocytic stages of P. falciparum now en route to licensure. There remains, however, a strong scientific rationale for the development of a highly effective additional vaccine component against the blood stages of the parasite, which could be deployed in conjunction with partially effective control measures against the pre-erythrocytic stages. Here, recent progress in the clinical development of blood-stage vaccines is reviewed, including methods of antigen selection, the limitations of in-vitro assays for selecting vaccines for clinical development, and the results of recently published clinical trials. This review seeks to summarize recent developments in our understanding of immunity to blood-stage parasites, as well as the relevant key advances made in vaccine technologies over the last decade. The future challenges that face this field of vaccine research are also described.
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Affiliation(s)
- A L Goodman
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
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Ouattara A, Mu J, Takala-Harrison S, Saye R, Sagara I, Dicko A, Niangaly A, Duan J, Ellis RD, Miller LH, Su XZ, Plowe CV, Doumbo OK. Lack of allele-specific efficacy of a bivalent AMA1 malaria vaccine. Malar J 2010; 9:175. [PMID: 20565971 PMCID: PMC2908102 DOI: 10.1186/1475-2875-9-175] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 06/21/2010] [Indexed: 12/03/2022] Open
Abstract
Background Extensive genetic diversity in vaccine antigens may contribute to the lack of efficacy of blood stage malaria vaccines. Apical membrane antigen-1 (AMA1) is a leading blood stage malaria vaccine candidate with extreme diversity, potentially limiting its efficacy against infection and disease caused by Plasmodium falciparum parasites with diverse forms of AMA1. Methods Three hundred Malian children participated in a Phase 2 clinical trial of a bivalent malaria vaccine that found no protective efficacy. The vaccine consists of recombinant AMA1 based on the 3D7 and FVO strains of P. falciparum adjuvanted with aluminum hydroxide (AMA1-C1). The gene encoding AMA1 was sequenced from P. falciparum infections experienced before and after immunization with the study vaccine or a control vaccine. Sequences of ama1 from infections in the malaria vaccine and control groups were compared with regard to similarity to the vaccine antigens using several measures of genetic diversity. Time to infection with parasites carrying AMA1 haplotypes similar to the vaccine strains with respect to immunologically important polymorphisms and the risk of infection with vaccine strain haplotypes were compared. Results Based on 62 polymorphic AMA1 residues, 186 unique ama1 haplotypes were identified among 315 ama1 sequences that were included in the analysis. Eight infections had ama1 sequences identical to 3D7 while none were identical to FVO. Several measures of genetic diversity showed that ama1 sequences in the malaria vaccine and control groups were comparable both at baseline and during follow up period. Pre- and post-immunization ama1 sequences in both groups all had a similar degree of genetic distance from FVO and 3D7 ama1. No differences were found in the time of first clinical episode or risk of infection with an AMA1 haplotype similar to 3D7 or FVO with respect to a limited set of immunologically important polymorphisms found in the cluster 1 loop of domain I of AMA1. Conclusion This Phase 2 trial of a bivalent AMA1 malaria vaccine found no evidence of vaccine selection or strain-specific efficacy, suggesting that the extreme genetic diversity of AMA1 did not account for failure of the vaccine to provide protection.
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Affiliation(s)
- Amed Ouattara
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, Pharmacy and Dentistry, Bamako, Mali
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Ma Y, Poisson L, Sanchez-Schmitz G, Pawar S, Qu C, Randolph GJ, Warren WL, Mishkin EM, Higbee RG. Assessing the immunopotency of Toll-like receptor agonists in an in vitro tissue-engineered immunological model. Immunology 2010; 130:374-87. [PMID: 20331478 DOI: 10.1111/j.1365-2567.2009.03237.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
SUMMARY The in vitro Peripheral Tissue Equivalent (PTE) module is a three-dimensional tissue-engineered endothelial cell/collagen matrix culture system, which has been reported to reproduce in vivo physiological conditions and which generates dendritic cells (DC) autonomously. In the present study, we used the PTE module to investigate the immunopotency of Toll-like receptor (TLR) agonists, including polyinosine-polycytidylic acid, Gardiquimod, CpG 2006 and lipopolysaccharide. Application of TLR agonists in the PTE module induced a wide range of cytokines, including interleukins 1alpha/beta, 6, 8 and 10 and tumour necrosis factor-alpha. Compared with traditional peripheral blood mononuclear cell (PBMC) cultures, the PTE module produced twofold to 100-fold higher levels of cytokine secretion, indicating that it can be a highly sensitive assay system. This increased sensitivity is the result of the natural synergy between the leucocytes and the endothelium. Furthermore, the application of TLR agonists, such as lipopolysaccharide and Gardiquimod, to the PTE module enhanced DC differentiation and promoted DC maturation, as indicated by up-regulated expression of CD83, CD86 and CCR7(CD197). In addition, functional assays indicated PTE-derived DC treated with Gardiquimod, a TLR-7 agonist, significantly augmented anti-tetanus toxoid antibody production. Interestingly, replacing PBMC with purified myeloid cells (CD33(+)) significantly reduced the responsiveness of the PTE module to TLR stimulation. The reduced sensitivity was partly the result of the removal of plasmacytoid DC that participated in the response to TLR stimulation and sensitization of the PTE module. Overall, the in vitro PTE module clearly demonstrated the effects of TLR agonists on DC generation, maturation and antigen-presenting capacity, and may serve as a sensitive and predictive test bed for the evaluation of adjuvant candidates.
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Affiliation(s)
- Yifan Ma
- VaxDesign Corporation, Orlando, FL 32826, USA
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Crosby L, Casey W, Morgan K, Ni H, Yoon L, Easton M, Misukonis M, Burleson G, Ghosh DK. Murine J774 macrophages recognize LPS/IFN-g, non-CpG DNA or two-CpG DNA-containing sequences as immunologically distinct. Nitric Oxide 2010; 22:242-57. [PMID: 20097302 DOI: 10.1016/j.niox.2010.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 12/17/2009] [Accepted: 01/17/2010] [Indexed: 11/26/2022]
Abstract
Specific bacterial lipopolysaccharides (LPS), IFN-gamma, and unmethylated cytosine or guanosine-phosphorothioate containing DNAs (CpG) activate host immunity, influencing infectious responses. Macrophages detect, inactivate and destroy infectious particles, and synthetic CpG sequences invoke similar responses of the innate immune system. Previously, murine macrophage J774 cells treated with CpG induced the expression of nitric oxide synthase 2 (NOS2) and cyclo-oxygenase 2 (COX2) mRNA and protein. In this study murine J774 macrophages were exposed to vehicle, interferon gamma+lipopolysaccharide (IFN-g/LPS), non-CpG (SAK1), or two-CpG sequence-containing DNA (SAK2) for 0-18h and gene expression changes measured. A large number of immunostimulatory and inflammatory changes were observed. SAK2 was a stronger activator of TNFalpha- and chemokine expression-related changes than LPS/IFN-g. Up regulation included tumor necrosis factor receptor superfamily genes (TNFRSF's), IL-1 receptor signaling via stress-activated protein kinase (SAPK), NF-kappaB activation, hemopoietic maturation factors and sonic hedgehog/wingless integration site (SHH/Wnt) pathway genes. Genes of the TGF-beta pathway were down regulated. In contrast, LPS/IFN-g-treated cells showed increased levels for TGF-beta signaling genes, which may be linked to the observed up regulation of numerous collagens and down regulation of Wnt pathway genes. SAK1 produced distinct changes from LPS/IFN-g or SAK2. Therefore, J774 macrophages recognize LPS/IFN-g, non-CpG DNA or two-CpG DNA-containing sequences as immunologically distinct.
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Affiliation(s)
- Lynn Crosby
- University of Tennessee Health Sciences Center, Department of Physiology, Memphis, TN 38163, USA.
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Ellis RD, Martin LB, Shaffer D, Long CA, Miura K, Fay MP, Narum DL, Zhu D, Mullen GED, Mahanty S, Miller LH, Durbin AP. Phase 1 trial of the Plasmodium falciparum blood stage vaccine MSP1(42)-C1/Alhydrogel with and without CPG 7909 in malaria naïve adults. PLoS One 2010; 5:e8787. [PMID: 20107498 PMCID: PMC2809736 DOI: 10.1371/journal.pone.0008787] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Accepted: 12/02/2009] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Merozoite surface protein 1(42) (MSP1(42)) is a leading blood stage malaria vaccine candidate. In order to induce immune responses that cover the major antigenic polymorphisms, FVO and 3D7 recombinant proteins of MSP1(42) were mixed (MSP1(42)-C1). To improve the level of antibody response, MSP1(42)-C1 was formulated with Alhydrogel plus the novel adjuvant CPG 7909. METHODS A Phase 1 clinical trial was conducted in healthy malaria-naïve adults at the Center for Immunization Research in Washington, D.C., to evaluate the safety and immunogenicity of MSP1(42)-C1/Alhydrogel +/- CPG 7909. Sixty volunteers were enrolled in dose escalating cohorts and randomized to receive three vaccinations of either 40 or 160 microg protein adsorbed to Alhydrogel +/- 560 microg CPG 7909 at 0, 1 and 2 months. RESULTS Vaccinations were well tolerated, with only one related adverse event graded as severe (Grade 3 injection site erythema) and all other vaccine related adverse events graded as either mild or moderate. Local adverse events were more frequent and severe in the groups receiving CPG. The addition of CPG enhanced anti-MSP1(42) antibody responses following vaccination by up to 49-fold two weeks after second immunization and 8-fold two weeks after the third immunization when compared to MSP1(42)-C1/Alhydrogel alone (p<0.0001). After the third immunization, functionality of the antibody was tested by an in vitro growth inhibition assay. Inhibition was a function of antibody titer, with an average of 3% (range -2 to 10%) in the non CPG groups versus 14% (3 to 32%) in the CPG groups. CONCLUSION/SIGNIFICANCE The favorable safety profile and high antibody responses induced with MSP1(42)-C1/Alhydrogel + CPG 7909 are encouraging. MSP1(42)-C1/Alhydrogel is being combined with other blood stage antigens and will be taken forward in a formulation adjuvanted with CPG 7909. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00320658.
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Affiliation(s)
- Ruth D Ellis
- Malaria Vaccine Development Branch, National Institute of Allergy and Infectious Diseases/National Institutes of Health, Rockville, Maryland, USA.
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