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Johns Hopkins Malaria Research Institute

Episode #2 | 1 October 2021

Preventing Malaria During the Rainy Season

A new trial investigates whether drugs or vaccines – or a combination of both – are most effective at preventing malaria during the seasonal period, and the WHO’s malaria director considers the current situation in malaria eradication.

The return of mosquitos during the rainy season results in particularly high malaria transmission. During this ‘seasonal period’, drugs are often given to prevent the disease through what’s known as seasonal malaria chemoprevention, or SMC. Yet, despite these interventions, transmission often remains high. In a three-year trial of nearly 7,000 children, the RTS,S vaccines were shown to be as good as SMC in preventing malaria during the seasonal period. But when the two interventions were combined, the number of malaria events fell substantially - to almost a third of the single intervention groups. RTS,S could, therefore, be used as a seasonal vaccine, with an annual booster just before peak transmission. And the WHO’s malaria chief, Dr Pedro Alonso, has highlighted the potential of vaccines and new technology to solve the malaria problem, but reinforced the need for universal access to healthcare and better use of data.