Malaria vaccine

Since October 2023, the World Health Organization (WHO) has recommended the use of malaria vaccines to prevent a specific type of malaria, caused by the parasite P. falciparum, for children living in areas where this type of malaria is common. P. falciparum is the deadliest type of malaria and is most common across Africa. This programme has been prioritised to specific areas where the risk of malaria is high.

There are two malaria vaccines currently available for use in these areas: RTS,S/AS01 and R21/Matrix-M. Both vaccines prevent around 75% of malaria cases when given before the malaria season in areas where large amounts of the disease spread every season.

In October 2021, RTS,S/AS01 was the first malaria vaccine to be recommended by the WHO. In October 2023, R21/Matrix-M became the second vaccine to be recommended and is eventually expected to provide enough supply to benefit all children living in areas where malaria is a risk.

The RTS,S/AS01 malaria vaccine was first used in pilot evaluations in 3 countries resulting in a 13% drop in death among children age-eligible for vaccination. There was also a substantial reduction in hospitalizations for severe malaria. More than 2 million children have already received the RTS,S/AS01 vaccine.

In clinical trials, the R21/Matrix-M vaccine reduced symptomatic cases of malaria by 75% during the 12 months following a 3-dose series. A fourth dose given a year after the third maintained the protection.

Malaria: The real-world impact of the first malaria vaccine in Kenya

Announced in July 2023, 12 countries in Africa have been allocated a total of 18 million doses of RTS,S/AS01 for the 2023–2025 period. The supply of malaria vaccines is still somewhat limited, and to ensure the vaccine is prioritised correctly, a “framework of allocation” has been created by the WHO. 

The RTS,S vaccine will be rolled out in some African countries in early 2024, and the R21 malaria vaccine is expected to become available to countries mid-2024, with the first shipment (43,200 doses) having been released to the Central African Republic on 20thMay

Both malaria vaccines should be given to children in a schedule of 4 doses from around 5 months of age. Vaccination programmes may give the first dose at a later or slightly earlier age based on operational considerations.

A fifth dose, given one year after the fourth dose, may be given to children in areas where there is still a high risk of disease after four doses.

In specific areas where malaria may be seasonal, or have seasonal peaks, the vaccine may be given on an age-based approach, or a seasonal-based approach, or a combination of the two.

The RTS,S/AS01 vaccine should not be given to anyone with allergy to the ingredients of the vaccine, or who has had sensitivity to a previous dose of the RTS,S/AS01 or hepatitis B vaccine.

18 million doses of first-ever malaria vaccine allocated to 12 African countries for 2023–2025

Side effects for the RTS,S/01 vaccine, as described in the summary of product characteristics.

Very common side effects include:

• Irritability
• fever (high temperature)
• swelling or pain at the site of injection

Common side effects include:

• decreased appetite
• drowsiness
• diarrhoea

Uncommon side effects include:

• febrile convulsions (fits) within seven days of receiving the vaccine
• vomiting (being sick)
• thickening or hardening of the skin at the site of injection.

RTS,S/AS01

Other than the antigens (the P. falciparum circumsporozoite protein fused with hepatitis B surface antigen (RTS), and combined with hepatitis B surface antigen), RTS,S/AS01 contains various other ingredients that act as stabilisers or adjuvants. These include:

• Sucrose,
• polysorbate 80,
• disodium phosphate dihydrate,
• sodium dihydrogen phosphate dihydrate
• Dioleoyl phosphatidylcholine (DOPC),
• cholesterol,
• sodium chloride,
• disodium phosphate anhydrous,
• potassium dihydrogen phosphate (39 mg per dose),

Lifesaving malaria vaccine: harnessing innovation to fight an ancient killer

More than 28 countries in Africa plan to introduce a WHO-recommended malaria vaccine as part of their national immunisation programmes. This will be supported by Gavi, the Vaccine Alliance, who has agreed to provide technical and financial support to roll out malaria vaccines to 18 countries.

The RTS,S vaccine will be rolled out in some African countries in early 2024, and the R21 malaria vaccine is expected to become available to countries mid-2024, with the first shipment already released to the Central African Republic on 20th May.RTS,S/AS01 can be given at the same time as other injectable vaccines but should always be given at different injection sites.

RTS,S/AS01 can be given at the same time as any of the following vaccines; diphtheria (D), tetanus (T), whole cell pertussis (Pw), acellular pertussis (Pa), hepatitis B (HepB), Haemophilus influenzae type b (Hib), oral polio (OPV), measles, rubella, yellow fever, rotavirus and pneumococcal conjugate vaccines (PCV) as there are no reported interference regarding protection or immunity. The co-administration of RTS,S/AS01 with PCV increases the risk of fever within 7 days post-vaccination.