To assess why this is, 65 healthy Malawian adults were vaccinated with PCV13, before researchers measured antibody levels in both the blood and nose, as well as serotype-specific B cells, prior to and after vaccination. The vaccine stimulated strong immune responses against serotype 6B, increasing both antibodies and targeted B cells, but it did not produce a meaningful increase in responses against serotype 3.
These findings suggest that the vaccine does not produce a strong immune response to serotype 3, which may help explain why it continues to persist. Establishing this link is an important step forward in tackling this strain of pneumococcal bacteria, highlighting the need for alternative vaccines to better address the continued carriage and disease caused by this serotype 3.
Dennis added: "This paper came to fruition through a valuable knowledge exchange programme funded by BactiVac, which facilitated a true two-way collaboration between us at LUMC and researchers at MLW in Malawi. Through mutual visits in 2024, we were able to transfer our methodology for antigen-specific B cell characterisation and implement it in an ongoing trial. As well as being a joy to get to know Godwin, Prof. Stephen Gordon, and the other MLW researchers, this kind of collaborative capacity-building is essential for gaining locally relevant insights and moving toward more effective strategies to tackle pneumococcal disease."
Read the paper here.
Pneumonia study with Malawi collaborators
LUCID researchers dr. Dennis Hoving, Alicia de Kroon, dr. Simon Jochems, and Godwin Tembo at the Malawi Liverpool Wellcome Research Programme, studied how adults in Malawi respond to PCV13. This vaccine protects against multiple types of pneumococcal bacteria that can cause pneumonia and other serious infections. Although the vaccine has reduced disease overall, one type (serotype 3) continues to spread, especially in high-transmission settings.
