Understanding immunity mediated by the RTS,S malaria vaccine in children

The RTS,S vaccine has recently been recommended for implementation as a childhood vaccine in regions with moderate to high malaria transmission.

Although promising, the RTS,S vaccine does have important limitations. Vaccine efficacy is modest and short-lived. In children aged 5-17 months efficacy was 55% over the first 12 months after the primary course of vaccination (3 doses).

Given the rapid waning of protective immunity, a booster dose is recommended 12-18 months after completing the primary immunization. The precise mechanisms and correlates of immunity for RTS,S are not well understood, but this knowledge is needed to optimize the impact of the vaccine against malaria and to inform strategies to build on RTS,S to develop more protective and long-lasting vaccines.

Overall objectives: Develop strategies to improve the level of protection and effectiveness of the RTS,S vaccine in malaria-endemic countries, and support the development of new more protective vaccines for the future.

Specific objectives:

1. Quantify the immune mechanisms induced by the RTS,S vaccine in children that mediate protection from malaria.
2. Identify immune correlates of protection for the RTS,S vaccine.
3. Understand how strain variation in malaria impacts on the effectiveness of the RTS,S vaccine.

2019-Ongoing

We are researching the immune responses induced by the RTS,S vaccine among young children in large studies of children multiple malaria-endemic countries across Africa where the burden of malaria is highest.

We combine powerful and innovative immunological analysis that define immune functions and specific targets of immune responses with advanced biostatistical analyses and modelling approaches. We are also analysing how polymorphisms or variations that occur in naturally-circulating malaria strains in Africa may enable the evasion of vaccine-induced immunity.

The majority of malaria deaths and disease occurs in young children in African countries. Malaria is one of the world’s leading causes of death for young children. By understanding how the RTS,S vaccine works to protect against malaria, and why it is not more protective, we hope to develop strategies to improve the impact of RTS,S against malaria and help advance the development of more protective and long-lasting vaccines. This will reduce illness and death among children globally.