Quantitative PCR used to test vaccines in human experimental malaria.

2004 NOV 3 - (NewsRx.com & NewsRx.net) -- Scientists have performed a statistical analysis of malaria parasitemia measured by a quantitative real-time polymerase chain reaction.

"Clinical trials are an essential step in evaluation of safety and efficacy of malaria vaccines, and human experimental malaria infections have been used for evaluation of protective immunity of Plasmodium falciparum malaria. In this study, a quantitative real-time polymerase chain reaction was used to measure P. falciparum malaria parasitemia in non-immune volunteers who had been experimentally infected by mosquito bites," scientists in the Netherlands report.

"Based on a remarkably small variation in the kinetics of parasitemia, a statistical model was developed that provides detailed estimates of pre-patent periods and parasite multiplication of blood stages," said Cornelus C. Hermsen and collaborators at Nijmegen University Medical Center and Erasmus University Medical Center. "Using this model, we could predict results on vaccine efficacy for pre-erythrocytic vaccines in the asymptomatic incubation period, and asexual stage vaccines after a limited number of multiplication cycles."

The investigators concluded, "The model shows that stage-specific vaccines even with limited efficacy can be highly ...