An efficacy trial of the malaria vaccine SPf66 in Gambian infants - second year of follow-up

In 1994, 630 Gambian infants were immunized with three doses of the synthetic polypeptide malaria vaccine SPf66 or with a control vaccine. No significant protection against first or total attacks of malaria was observed among the children who received SPf66. However the period of follow-up was short. Thus, 532 children were followed for a second malaria transmission season during which 291 episodes of malaria were detected. Protective efficacies of SPf66 against first attacks of malaria and against all attacks of malaria were 8% [95% CI -20%, 30%] and 2% [95% CI -26% 24%] respectively. SPf66 did not provide any significant degree of protection to Gambian infants during a second year of follow-up. (C) 1997 Elsevier Science Ltd.