Why some people get malaria but don't get sick

Scientists studied adult volunteers from Kenya who lived in areas with widespread malaria and found several proteins of the parasite against which protected people were more likely to develop antibodies.

Details

The study involved 142 adult volunteers from Kenya. They all lived in regions where malaria is common, so their immune systems may have encountered the parasite before.

First, the participants had their blood drawn and tested to see what antibodies they had. The researchers were interested in proteins from the malaria parasite Plasmodium falciparum, which is what causes one of the most dangerous forms of the disease.

The volunteers were then infected with a low dose of the parasite under controlled medical conditions and their condition was monitored. Doctors monitored their temperature, symptoms and the amount of parasites in their blood.

Some of the participants showed signs of illness. But 86 people remained healthy and did not require treatment during the observation. This means that their bodies were able to contain the infection so that it did not develop into clinical malaria.

After analysing the data, the scientists identified six proteins in the parasite that were associated with protection: MSP1, MSP11, RAMA, MSP7, PHISTB and PTEX150.

It was not the presence of antibodies to a single protein that proved particularly important, but the combination of proteins. In people with the strongest defences, the immune system recognised several of these targets at once.

Why it matters

Malaria remains one of the most dangerous infections in the world. It causes hundreds of millions of cases each year, and it affects African countries and children the most.

There are vaccines against malaria, but they give incomplete protection and the effect diminishes over time. So scientists are looking for new targets to help create more effective vaccines.

This study shows which parts of the parasite the immune system can recognise in people with natural defences. Such proteins could form the basis for future vaccines or new approaches to prevention.

But it's not yet a ready-made drug or the "secret to complete invulnerability." It's about partial protection: a person can get infected but not get sick or carry the infection more easily.

Background

In areas where malaria is persistent, people may encounter the parasite many times in their lives. After repeated infections, a portion of the population gradually develops a naturally acquired immunity.

This immunity does not usually block the infection completely. Rather, its task is to prevent the parasite from multiplying too much in the blood and causing severe symptoms.

This is why scientists are studying people who live in malarial regions and do not get sick after infection. Their immune systems can tell them what defence mechanisms are really at work.

Source

A study by Rodney Ogwang et al. Controlled human malaria infection in adults identifies combinations of merozoite antigens associated with clinical immunity published in Nature Communications in 2026. The authors studied 142 adult volunteers from Kenya and identified combinations of malaria parasite proteins associated with natural clinical defences against the disease.