For the last few years, the world has been badly needing a vaccine for malaria. The disease affected 200 million people (of whom close 600,000 died) in 2013, mostly in poor and developing nations in Africa and Asia even as many strains of the malarial pathogen Plasmodium have either developed resistance to some of the drugs (the most prominent being artemisinin) or have become more virulent. Thus, GlaxoSmithKline PLC’s new vaccine—despite its partial effectiveness—offers a clear benefit to children in countries where the burden for the disease is high, India included.
Results of the last phase of five-year long clinical trials, published in The Lancet, show that the vaccine loses effectiveness over time, despite booster doses being administered. While initial studies showed that vaccinated children were half as likely as their unvaccinated peers to contract malaria, follow-on studies showed that the level of protection dropped to just 36% in four years of the first shot, even though a booster dose being administered after the 18-month mark. Amongst infants, the effectiveness was still lower. The vaccine is nowhere close to 80%-effectiveness levels of the vaccines used in routine programmes to control other diseases. However, the medical community believes that, used along with the existing interventions to control malaria, it will help children in tropical countries to beat the disease in their early years, when malaria-caused mortality is high. It is a sign of the growing burden of the disease that the WHO is ready to add the vaccine to its list of recommended vaccines if it receives regulatory clearance.