NANP]19-5.1. A malaria vaccine field trial in Nigerian children
Reber-Liske, R.; Salako, L.A.; Matile, H.; Sowunmi, A.; Stürchler, D.
Tropical and Geographical Medicine 47(2): 61-63
1995
ISSN/ISBN: 0041-3232 PMID: 8592764 Document Number: 441747
[NANP]19-5.1 is a recombinant Plasmodium falciparum vaccine consisting of 19 repeats of the sporozoite surface protein (NANP) and the schizont export antigen (5.1). In a previous study, an experimentally infected subject (with a history of malaria exposure and an elevated pre-immunization lymphocyte stimulation index to antigen 5.1) showed parasitaemia but no signs of clinical malaria. In an attempt to find a comparable partially immune population, the vaccine was tested in 194 Nigerian schoolchildren aged 6-12 years, with vaccine and placebo groups of equal size. These children already possessed a certain degree of immunity and it was hoped that this immunity would be boosted by the vaccine. During the 12 weeks of observation, none of the children developed clinical malaria. Analysis of serum taken before and after immunization revealed that, except for 8 children, they all had considerable levels of antibodies to both antigens. It is concluded that the trial should be repeated in younger children who are still vulnerable to clinical malaria.