» Articles » PMID: 17124530

Safety and Allele-specific Immunogenicity of a Malaria Vaccine in Malian Adults: Results of a Phase I Randomized Trial

Abstract

Objectives: The objectives were to evaluate the safety, reactogenicity, and allele-specific immunogenicity of the blood-stage malaria vaccine FMP1/AS02A in adults exposed to seasonal malaria and the impact of natural infection on vaccine-induced antibody levels.

Design: We conducted a randomized, double-blind, controlled phase I clinical trial.

Setting: Bandiagara, Mali, West Africa, is a rural town with intense seasonal transmission of Plasmodium falciparum malaria.

Participants: Forty healthy, malaria-experienced Malian adults aged 18-55 y were enrolled.

Interventions: The FMP1/AS02A malaria vaccine is a 42-kDa recombinant protein based on the carboxy-terminal end of merozoite surface protein-1 (MSP-1(42)) from the 3D7 clone of P. falciparum, adjuvanted with AS02A. The control vaccine was a killed rabies virus vaccine (Imovax). Participants were randomized to receive either FMP1/AS02A or rabies vaccine at 0, 1, and 2 mo and were followed for 1 y.

Outcome Measures: Solicited and unsolicited adverse events and allele-specific antibody responses to recombinant MSP-1(42) and its subunits derived from P. falciparum strains homologous and heterologous to the 3D7 vaccine strain were measured.

Results: Transient local pain and swelling were more common in the malaria vaccine group than in the control group (11/20 versus 3/20 and 10/20 versus 6/20, respectively). MSP-1(42) antibody levels rose during the malaria transmission season in the control group, but were significantly higher in malaria vaccine recipients after the second immunization and remained higher after the third immunization relative both to baseline and to the control group. Immunization with the malaria vaccine was followed by significant increases in antibodies recognizing three diverse MSP-1(42) alleles and their subunits.

Conclusions: FMP1/AS02A was well tolerated and highly immunogenic in adults exposed to intense seasonal malaria transmission and elicited immune responses to genetically diverse parasite clones. Anti-MSP-1(42) antibody levels followed a seasonal pattern that was significantly augmented and prolonged by the malaria vaccine.

Citing Articles

Malaria vaccines: a new era of prevention and control.

Duffy P, Gorres J, Healy S, Fried M Nat Rev Microbiol. 2024; 22(12):756-772.

PMID: 39025972 DOI: 10.1038/s41579-024-01065-7.


Inclusion of an Optimized Merozoite Surface Protein 2-Based Antigen in a Trivalent, Multistage Malaria Vaccine.

Eacret J, Parzych E, Gonzales D, Burns Jr J J Immunol. 2021; 206(8):1817-1831.

PMID: 33789984 PMC: 8026686. DOI: 10.4049/jimmunol.2000927.


Maintaining immunogenicity of blood stage and sexual stage subunit malaria vaccines when formulated in combination.

Parzych E, Miura K, Long C, Burns Jr J PLoS One. 2020; 15(4):e0232355.

PMID: 32348377 PMC: 7190115. DOI: 10.1371/journal.pone.0232355.


Microarray analyses reveal strain-specific antibody responses to Plasmodium falciparum apical membrane antigen 1 variants following natural infection and vaccination.

Bailey J, Berry A, Travassos M, Ouattara A, Boudova S, Dotsey E Sci Rep. 2020; 10(1):3952.

PMID: 32127565 PMC: 7054363. DOI: 10.1038/s41598-020-60551-z.


Immunoglobulin G subclass and antibody avidity responses in Malian children immunized with Plasmodium falciparum apical membrane antigen 1 vaccine candidate FMP2.1/AS02.

Berry A, Gottlieb E, Kouriba B, Diarra I, Thera M, Dutta S Malar J. 2019; 18(1):13.

PMID: 30658710 PMC: 6339315. DOI: 10.1186/s12936-019-2637-x.


References
1.
Coulibaly D, Diallo D, Thera M, Dicko A, Guindo A, Kone A . Impact of preseason treatment on incidence of falciparum malaria and parasite density at a site for testing malaria vaccines in Bandiagara, Mali. Am J Trop Med Hyg. 2003; 67(6):604-10. DOI: 10.4269/ajtmh.2002.67.604. View

2.
Wu J, Gardner B, Murphy C, Seals J, Kensil C, Recchia J . Saponin adjuvant enhancement of antigen-specific immune responses to an experimental HIV-1 vaccine. J Immunol. 1992; 148(5):1519-25. View

3.
Tanabe K, Mackay M, Goman M, Scaife J . Allelic dimorphism in a surface antigen gene of the malaria parasite Plasmodium falciparum. J Mol Biol. 1987; 195(2):273-87. DOI: 10.1016/0022-2836(87)90649-8. View

4.
Angov E, Aufiero B, Turgeon A, Van Handenhove M, Ockenhouse C, Kester K . Development and pre-clinical analysis of a Plasmodium falciparum Merozoite Surface Protein-1(42) malaria vaccine. Mol Biochem Parasitol. 2003; 128(2):195-204. DOI: 10.1016/s0166-6851(03)00077-x. View

5.
Darko C, Angov E, Collins W, Bergmann-Leitner E, Girouard A, Hitt S . The clinical-grade 42-kilodalton fragment of merozoite surface protein 1 of Plasmodium falciparum strain FVO expressed in Escherichia coli protects Aotus nancymai against challenge with homologous erythrocytic-stage parasites. Infect Immun. 2004; 73(1):287-97. PMC: 538964. DOI: 10.1128/IAI.73.1.287-297.2005. View