Editorial: A ray of hope

More than a century of waiting has ended. The World Health Organization’s approval for the first anti-malaria vaccine is a path-breaking development that is set to change the course of public health history. Nearly 130 years after scientists first identified the Plasmodium parasites behind malaria, the world now has a vaccine — RTS, S — funded mainly by the Bill & Melinda Gates Foundation and London-based pharmaceutical firm GlaxoSmithKline (GSK). While this is certainly a boon for millions, particularly in poor countries in Africa and Asia, the expectations about the vaccine must be tempered because its efficacy is only 30%. However, the vaccine is expected to significantly reduce the severity of cases and prevent deaths. The excitement over the vaccine should not be allowed to overshadow the existing malaria control measures, including insecticide programmes. Malaria kills about half a million people each year, nearly 95% of them in sub-Saharan Africa — including 2.60 lakh children under the age of five years. At a potential cost of about $5 per dose, the vaccine rollout, including its distribution, would cost around $325 million to administer each year across ten African countries where the incidence of malaria is very high. Ensuring equity of access is key to the success of this vaccine. A modelling study last year estimated that if the vaccine were rolled out to countries with the highest incidence of malaria, it could prevent 5.4 million cases and 23,000 deaths in children below five years.

Malaria research is a field that has seen consistent failure of vaccine candidates in clinical trials because teaching the immune system to fight a parasite is much harder compared to fighting viruses or bacteria. Malaria parasites have found many ways to evade the defences of humans as the pathogen has more than 5,000 genes, making it adept at disabling the immune system in a number of ways. In comparison, the coronavirus has just 12 genes, and its spike protein was a relatively easier target for scientists. The malaria parasite, carried by mosquitoes, is a particularly insidious enemy because it can strike the same person over and over. In many parts of sub-Saharan Africa, even those where most people sleep under insecticide-treated bed nets, children have on average six malaria episodes a year. Bed nets, the most widespread preventive measure, cut malaria deaths in children under five only by about 20%. Against this grim backdrop, the new vaccine, even with modest efficacy, is the best weapon in the fight against the disease. The WHO has projected the demand for malaria vaccines to be 50-110 million doses per year by 2030.