A Sudanese man suffering from malaria lies on a cart as he waits for a clinic to open, in Adre, Chad on August 2, 2023. Image Credit: REUTERS

A naturally occurring bacteria found by GSK scientists has been shown to significantly cut the amount of malaria parasite in mosquitoes, a potentially important finding for efforts to stop the disease that kills more than 600,000 people a year.

The bacteria known as TC1 lowered the parasite load in both the mosquito's gut and salivary glands, and has the potential to reduce transmission to humans, according to a study published Thursday in the journal Science.

By 2030, the World Health Organization aims to reduce both the incidence of malaria and mortality from the disease by 90%, and to eliminate it in 35 countries. Yet the parasite is becoming resistant to widely used drugs and insecticides - and there is the threat that climate change will push transmission from mostly tropical areas into new regions.

Importantly, TC1 doesn't kill the insect or affect it's ability to reproduce, which means there is little potential for the mosquito or the parasite to develop a resistance to the bacteria, according to researchers from GSK, Johns Hopkins Malaria Research Institute and Fundacin MEDINA. The bacteria is also believed to be environmentally safe.

How this biological control could be deployed is still being examined. Possibilities include using existing methods such as treating water where mosquitoes breed, in feed traps and coating or spraying indoor surfaces and bed nets. These are already widely used practices in Africa, which accounted for 95% of the 247 million global cases in 2021.

The research includes data from preliminary semi-field studies conducted with Institut de Recherche en Sciences de la Sant in a contained facility in Burkina Faso. The next step would be bigger field studies.

GSK developed the first vaccine for the mosquito-borne disease in 2021 after more than three decades of work and about $1 billion in investment.