Decline in efficacy of Mosquirix vaccine for malaria after seven years.- GSK

The world's first malaria vaccine, RTS,S (Mosquirix) developed by GlaxoSmithKline, provides some protection after three doses but its effect declines to almost nothing after seven years according to a report published in The New England Journal of Medicine. The vaccine was designed for children in Africa where the disease is most active.

The results--published in the New England Journal of Medicine-- prompted researchers to question whether the vaccine can play a meaningful part in the fight against malaria. In the first year, Mosquirix cut the risk of contracting malaria by 35.9% but after 7 years, that difference was only 4.4%. And after 5 years, among children exposed to higher-than-average malaria rates, the vaccinated group saw 10 more cases than did the control group. Among children who received a booster fourth dose of the vaccine, the number of malaria episodes at four years fell by 36%, but without the booster dose, the advantage against the disease virtually disappeared. However in the most recent study, researchers estimated that Mosquirix averted 317 cases per 1,000 vaccinated children over the 7-year period.

See-"Seven-Year Efficacy of RTS,S/AS01 Malaria Vaccine among Young African Children."- Ally Olotu, Ph.D., Gregory Fegan, Ph.D., Juliana Wambua, M.Sc., George Nyangweso, B.Sc., Amanda Leach, M.R.C.P.C.H., Marc Lievens, M.Sc., David C. Kaslow, M.D., Patricia Njuguna, M.Med., Kevin Marsh, F.R.C.P., and Philip Bejon, Ph.D. N Engl J Med 2016; 374:2519-2529June 30, 2016DOI: 10.1056/NEJMoa1515257.