Malaria is a life-threatening disease spread to people by some types of mosquitoes. It is mostly found in tropical countries. Malaria is preventable and curable, but it still kills hundreds of thousands of people each year, most of them young children in Africa.
For a long time there was no vaccine against malaria. Today, the World Health Organization (WHO) recommends two malaria vaccines for children: RTS,S and R21. This page explains the disease, who gets the vaccines and when, and how vaccines work alongside bed nets and preventive medicines.
What Causes Malaria?
Malaria is caused by a parasite, not a virus or a bacterium. It does not spread from person to person. Instead, it spreads mostly through the bites of some infected female Anopheles mosquitoes. Blood transfusions and contaminated needles can also pass it on.
There are 5 Plasmodium parasite species that cause malaria in people. Two of them pose the greatest threat:
- P. falciparum is the deadliest malaria parasite and the most common one in Africa.
- P. vivax is the main malaria parasite in most countries outside sub-Saharan Africa.
Symptoms of Malaria
Symptoms usually start 10 to 15 days after a bite from an infected mosquito. The most common early symptoms are fever, headache and chills. Because these signs look like many other illnesses, early testing is important.
Severe symptoms include tiredness, confusion, seizures and difficulty breathing. Without treatment, P. falciparum malaria can progress to severe illness and death within 24 hours.
Some people are at higher risk of severe malaria:
- Babies and children under 5 years old.
- Pregnant women and girls.
- Travellers.
- People with HIV or AIDS.
Malaria during pregnancy can also cause early delivery or a baby with low birth weight.
People with severe symptoms should get emergency care right away. Because early symptoms are not specific, getting tested early is important. Early treatment can stop a mild case from becoming severe. See a healthcare provider if you have a fever during or after time in an area where malaria is common.
How Big Is the Problem?
According to WHO’s latest World malaria report, there were an estimated 282 million malaria cases and 610 000 malaria deaths in 2024. Cases rose by about 9 million (3%) compared with 2023, and deaths rose from 598 000.
The burden falls most heavily on Africa:
- In 2024, the WHO African Region had 95% of malaria cases (265 million) and 95% of malaria deaths (579 000).
- Children under 5 accounted for about 75% of all malaria deaths in the Region.
- WHO estimates that about 438 000 African children died from malaria in 2024.
- Over half of all malaria deaths in the Region occurred in three countries: Nigeria (31.9%), the Democratic Republic of the Congo (11.7%) and Niger (6.1%).
There is progress too. In 2024, 37 countries reported fewer than 1000 local cases of malaria, up from 13 countries in 2000.
The Malaria Vaccines: RTS,S and R21
WHO recommended the first malaria vaccine, RTS,S/AS01, in October 2021. In October 2023, it recommended a second vaccine, R21/Matrix-M. Both vaccines act against P. falciparum. Both are safe and effective, and both are prequalified by WHO.
Who Gets Them
WHO recommends malaria vaccines to prevent P. falciparum malaria in children who live in areas where malaria is common. Areas of moderate and high transmission come first. Countries may also choose to offer the vaccine in low transmission areas.
The Schedule
- The vaccine is given in 4 doses to children from around 5 months of age.
- A 5th dose, one year after dose 4, may be considered where malaria is highly seasonal, or where risk stays high in the third year of life or later.
- In areas with highly seasonal malaria, countries may give the vaccine by age, by season, or by a mix of both.
How Well They Work
In phase 3 clinical trials, both vaccines reduced malaria cases by more than 50% during the first year after vaccination. This is the time when children are at the highest risk of illness and death. A fourth dose in the second year of life made protection last longer.
Where malaria is highly seasonal and children also get seasonal malaria chemoprevention, both vaccines prevent around 75% of malaria episodes when given seasonally.
The two vaccines have not been tested against each other in a head-to-head trial. WHO says there is no evidence to date that one works better than the other.
Results From the Pilot Programme
From 2019 to 2023, the Malaria Vaccine Implementation Programme (MVIP) gave RTS,S to more than 2 million children in Ghana, Kenya and Malawi through routine childhood immunization. An independent evaluation found:
- A 13% drop in deaths among children of vaccine age, due to the vaccine.
- A large reduction in hospital stays for severe malaria.
- More than 90% of children reached by at least one malaria prevention tool (the vaccine or a treated bed net).
Rollout Today
Today, 25 countries in Africa offer malaria vaccines as part of childhood immunization. More than 10 million children per year are targeted for vaccination across these countries. WHO says vaccine supply is now enough to meet demand. However, most countries give the vaccine below their national target scale because of limited funding.
Modelling estimates suggest that malaria vaccines could prevent about half a million child deaths by 2035 if they were scaled up in areas of moderate and high transmission.
Other Ways to Prevent Malaria
The vaccines work best as part of a wider plan. WHO says the highest impact comes when vaccines are used alongside other recommended tools, such as bed nets and preventive medicines.
Mosquito Nets and Spraying
Controlling mosquitoes is a vital part of malaria control. The two core methods are:
- Insecticide-treated nets (ITNs) for sleeping.
- Indoor residual spraying (IRS).
Some mosquitoes now resist common insecticides. Newer nets give better protection than nets treated only with pyrethroid insecticides, and they are becoming more widely available.
People can also lower their risk with mosquito repellents that contain DEET, IR3535 or icaridin, used after dusk.
Preventive Medicines
Preventive chemotherapy gives a full course of antimalarial medicine to at-risk groups at set times of high risk, whether or not they are infected. Types include:
- Perennial malaria chemoprevention (PMC).
- Seasonal malaria chemoprevention (SMC).
- Intermittent preventive treatment in pregnancy (IPTp) and in school-aged children (IPTsc).
- Post-discharge malaria chemoprevention (PDMC).
- Mass drug administration (MDA).
Advice for Travellers
Travellers to malaria areas should see a doctor several weeks before they leave. Some preventive medicines must start 2 to 3 weeks before departure. They should be taken on schedule during the stay and for 4 weeks after the last possible exposure.
Diagnosis and Treatment
WHO recommends that every suspected case of malaria be confirmed with a test, either microscopy or a rapid diagnostic test. Malaria always needs treatment with medicine. Artemisinin-based combination therapy is the most effective treatment for P. falciparum malaria.
Drug resistance is a growing concern. WHO has confirmed partial resistance to artemisinin in Eritrea, Rwanda, Uganda and the United Republic of Tanzania.
Vaccines in a Wider Picture
Malaria vaccines join a long list of childhood vaccines that save lives, from those for measles to tuberculosis. To learn more about how vaccines reach children, read about routine immunization and the costs of vaccination.
Sources
- World Health Organization. “Fact sheet about malaria.” https://www.who.int/news-room/fact-sheets/detail/malaria
- World Health Organization. “Malaria vaccines (RTS,S and R21).” https://www.who.int/news-room/questions-and-answers/item/q-a-on-rts-s-malaria-vaccine