(HealthDay News) – For infants, vaccination with the RTS,S/AS01 vaccine, coadministered with Expanded Program on Immunization (EPI) vaccines, is associated with modest protection against clinical and severe malaria, according to a study published online Nov 9 in the New England Journal of Medicine to coincide with presentation at the International African Vaccinology Conference, held from Nov 8–11 in Cape Town, South Africa.
Salim Abdulla, MD, PhD, and colleagues from the RTS,S Clinical Trials Partnership, examined the outcomes of 6,537 infants, aged 6–12 weeks, from a Phase 3 trial of RTS,S/AS01 for malaria. RTS,S/AS01 or a comparator vaccine was administered in conjunction with Expanded Program on Immunization (EPI) vaccines in a three-dose monthly schedule.
During the 14 months after the first dose of vaccine, the researchers found that the incidence of the first or only episode of clinical malaria was 0.31 per person-year in the RTS,S/AS01 group and 0.4 per person-year in the control group, for a vaccine efficacy of 30.1% in the intention-to-treat population. In the per-protocol population, vaccine efficacy was 31.3%. In the intention-to-treat and per-protocol populations the vaccine efficacy against severe malaria was 26% and 36.6%, respectively. The frequency of serious adverse events was similar between the groups. One month following administration of the third dose of RTS,S/AS01, 99.7% of those vaccinated were positive for anti-circumsporozoite antibodies.
“The RTS,S/AS01 vaccine coadministered with EPI vaccines provided modest protection against both clinical and severe malaria in young infants,” the authors write.
The study was partially funded by GlaxoSmithKline, to which several authors disclosed financial ties.