GSK's RTS,S malaria vaccine halves infection rate for up to 18 months

A new malaria vaccine under development by GlaxoSmithKline was recently shown to protect babies as young as five months old from malaria for up to 18 months after vaccination.

According to a new study published in PLOS Medicine, the vaccine-called RTS,S-was tested on more than 15,000 children between the ages of six weeks and 17 months from seven African countries.

Clinical rates of malaria in older age groups were cut in half with the vaccine, which was also 45 percent effective against severe malaria and 41 percent effective against hospitalization resulting from the disease. It was less effective, however, in children vaccinated in early infancy.

Results across the seven countries varied widely, from approximately 77 percent in Kenya to 41 percent in Burkina Faso. The vaccine worked the best in regions with the highest incidence of malaria.

Additionally, the study found meningitis was detected more often among older children who received the vaccine compared to those who received the control vaccine. The authors of the study said that while the relation could be coincidental, it warrants meningitis surveillance on a larger scale.

"It is very important to measure impact as well as efficacy when considering the potential role of a vaccine in contributing to public health," Brian Greenwood, a professor of clinical tropical medicine at the London School of Hygiene & Tropical Medicine, which conducted the study, said. "Impact is the factor that would guide a national malaria program in deciding where to introduce the vaccine. Even a vaccine with relatively low efficacy may be very useful and cost effective if introduced into a population where the infection that it prevents is very common."

Follow-up results for the 16-30 month period will be available at the end of the year. A dossier on the vaccine has been sent to the European Medicines Agency for a review that is expected sometime next year.