Abstract |
The malaria sporozoite vaccine candidate RTS,S, formulated with an oil-in-water emulsion plus the immunostimulants monophosphoryl lipid A and the saponin derivative QS21 ( vaccine 3), recently showed superior efficacy over two other experimental formulations. Immunized volunteers were followed to determine the duration of protective immune responses. Antibody levels decreased to between one-third and one-half of peak values 6 months after the last dose of vaccine. T cell proliferation and interferon-gamma production in vitro were observed in response to RTS,S or hepatitis B surface antigen. Seven previously protected volunteers received sporozoite challenge, and 2 remained protected (1/1 for vaccine 1, 0/1 for vaccine 2, and 1/5 for vaccine 3). The prepatent period was 10.8 days for the control group and 13.2 days for the vaccinees (P < .01). Immune responses did not correlate with protection. Further optimization in vaccine composition and/or immunization schedule will be required to induce longer-lasting protective immunity.
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Authors | J A Stoute, K E Kester, U Krzych, B T Wellde, T Hall, K White, G Glenn, C F Ockenhouse, N Garcon, R Schwenk, D E Lanar, P Sun, P Momin, R A Wirtz, C Golenda, M Slaoui, G Wortmann, C Holland, M Dowler, J Cohen, W R Ballou |
Journal | The Journal of infectious diseases
(J Infect Dis)
Vol. 178
Issue 4
Pg. 1139-44
(Oct 1998)
ISSN: 0022-1899 [Print] United States |
PMID | 9806046
(Publication Type: Clinical Trial, Controlled Clinical Trial, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Antibodies, Protozoan
- Malaria Vaccines
- Protozoan Proteins
- Vaccines, Synthetic
- circumsporozoite protein, Protozoan
- Interferon-gamma
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Topics |
- Adolescent
- Adult
- Antibodies, Protozoan
(blood)
- Disease-Free Survival
- Humans
- Interferon-gamma
- Malaria Vaccines
(immunology)
- Malaria, Falciparum
(prevention & control)
- Middle Aged
- Protozoan Proteins
(immunology)
- T-Lymphocytes
(immunology)
- Vaccination
- Vaccines, Synthetic
(immunology)
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