Placental Malaria (PM) constitutes a major health problem. Globally, malaria infection during pregnancy accounts for over 50,000 maternal and 200,000 neonatal deaths each year. An effective vaccine would be an attractive tool to control PM on its own, or to complement the existing yet imperfect tools.

The VAC4PM project partnership, led by the European Vaccine Initiative (EVI), will build on the success of previous pre-clinical and first-in-human clinical studies conducted in Europe and Africa. Results from clinical trials demonstrated that the two PM vaccine candidates PAMVAC and PRIMVAC are safe, well-tolerated and induce good homologous immune responses. Both vaccine candidates use similar but complementary approaches and consist of a single recombinant protein comprising the placental binding region of VAR2CSA.

This project seeks to further characterize the longevity of the PRIMVAC-induced immune response, as well as the capacity of the vaccine to boost and broaden a naturally acquired immune response. Another aspect of the project is to undertake the pre-clinical development of PAMVAC-CLP. PAMVAC-CLP is an improved version of PAMVAC, where a capsid-like particle (CLP) will be added as backbone, potentially improving immunogenicity, cross-reactivity and longevity of the induced immune response.

PRIMVAC and PAMVAC-CLP constitute a promising portfolio of PM vaccine candidates. Generated data will inform the next steps of PM vaccine development, including a decision on the formulation for further development and will allow the preparation of a larger phase II immunogenicity study.

Further reading: Gamain, Benoît et al. “Progress and Insights Toward an Effective Placental Malaria Vaccine.” Frontiers in immunology vol. 12 634508. 25 Feb. 2021, doi:10.3389/fimmu.2021.634508