Opinion: Climate change requires adapting malaria prevention campaigns

Drokas Dako is a health worker and mother from the Ségou region of Mali. During malaria season, she is out the door at 7 a.m. She walks kilometers, often in heavy rain, to ensure that all the children in her village have received their dose of a medicine to protect them from malaria — a deadly and common disease in her region.

Preventing malaria with seasonal campaigns

Malaria claims the lives of around 619,000 people annually worldwide, according to the latest data from 2021. Most of them are children under the age of five in the Sahel region of Africa, where access to health care is limited. Preventing disease with seasonally distributed medicines saves lives. In 2022 alone, the intervention protected over 48 million children in 17 countries, according to Medicines for Malaria Venture figures calculated based on manufacturer information. Dako’s role is critical: She distributes the medicines door-to-door during a campaign that is organized and timed according to the malaria season.

Malaria is a climate-sensitive disease

But what happens when climate change causes shifts in the malaria season, and therefore the timing and duration of these preventive campaigns?

Malaria is a disease that is sensitive to rainfall patterns, as heavy rainfall creates breeding conditions for mosquitoes that transmit the disease. Although rainfall patterns can shift due to many factors, a study conducted by the World Health Organization’s Special Programme for Research and Training in Tropical Diseases and the International Centre for Research and Development in Canada confirms that climate change is a key contributor. This causes mosquitoes to breed at different times and places, both reducing disease incidence in some areas and introducing the disease to new areas, where the population and health systems have no prior exposure. This makes seasonal distribution campaigns more challenging to plan and implement — and means more children may be at risk.

Malaria vaccines and preventive malaria medicines

Malaria vaccines can be distributed during any season, yet they address the needs of a more limited population than preventive medicines, and both vaccines and medicines for prevention are more powerful in combination.

Ghana and Nigeria are the first countries to have approved the R21 vaccine for children from 5 months to 3 years old. Seasonally distributed medicines are available in 17 countries for children aged 3 months to 5 years old. Some countries, such as Gambia, Mali, Niger and Senegal, have expanded this age range to up to 10 years, and others are evaluating the potential impact of following that example.

In seasonal transmission settings, chemoprevention medicines provide up to 88% protection. This compares to up to 77% for the R21 vaccine, according to Phase II trials and 28-46% for the RTS,S vaccine when used alone — without seasonally distributed medicines.

Preventive medicines are a critical tool, amongst others, in the malaria elimination toolbox; ensuring their continued — and possibly expanded — use will be key to protecting as many children as possible as seasonal patterns continue to shift.

Adapting malaria prevention campaigns to climate patterns  

Reaching Sustainable Development Goal 13 on climate action requires not only the reduction of carbon emissions, but adaptation to what are now considered the inevitable effects of climate change.

First, a better understanding of these patterns is needed. This requires data for better forecasting. Medicines for Malaria Venture, together with partners, is working to model trends in malaria transmission to be able to tailor seasonal distribution campaigns, and help countries adapt to the inevitable effects of climate change. The goal is to adjust the timing and duration of campaigns in each country and region, depending on local needs and transmission patterns.

In addition, we need continued investments in research and development to develop flexible, adaptable, and complementary tools. No one tool can defeat malaria. A suite of interventions that address a variety of needs — including medicines, vaccines, bed nets, and insecticides all have a crucial role to play in combatting the disease and mitigating the devastating effects of climate change. New tools are needed to address drug and insecticide resistance, and treat and prevent malaria in pregnant women and young children — two of the groups most affected by the disease.

Finally, cross-sectoral collaboration and continued commitment from international donors, national malaria control programs, and the malaria community are critical. Only then will we be able to ensure that health workers like Dako continue to have the tools they need to save lives in their communities — despite the changing climate.

For more information on protecting children with preventive medicines please visit this page.