A multi-antigen chimeric PvCSP-MSP1₁₉ vaccine induces robust humoral responses against distinct stages of Plasmodium vivax.

Authors

Laura L C L Diniz, Diego O Santos, Camila V Maffetano, Nathalia T Taguchi, Rodolfo F Marques, Tarsila M Camargo, Tatiane R Oliveira, Leoneide E M Bouillet, Guilherme A S Silva, Kenya E S Abreu, Xiomara A Gaitán, Daniel Y Bargieri, Silvia B Boscardin, Eduardo L V Silveira, Alba Marina Gimenez, Irene S Soares

Published in

Vaccine. Volume 93. Pages 129197. Oct 02, 2026. Epub Oct 02, 2026.

Abstract

Plasmodium vivax is the leading cause of malaria outside Africa, highlighting the need for an effective vaccine. However, the development of vaccines against this parasite remains challenging because of its complex life cycle and antigenic diversity. In this study, we evaluated vaccine formulations targeting both the pre-erythrocytic and erythrocytic stages of P. vivax using either individual antigens or a novel chimeric protein. The chimeric construct combined the C-terminal region and variant repeat domains of the P. vivax circumsporozoite protein (PvCSP) with the 19-kDa C-terminal fragment of merozoite surface protein 1 (PvMSP1₁₉). Structural predictions indicated that the PvCSP region was predominantly disordered, whereas the PvMSP1₁₉ domain displayed a more ordered conformation, supporting the preservation of key antigenic features within the fusion protein. We also evaluated recombinant replication-defective adenoviral vectors expressing PvCSP (AdC68-PvCSP) or PvMSP1₁₉ (AdHu5-PvMSP1₁₉). Homologous (protein/protein/protein) and heterologous (protein/adenovirus or adenovirus/protein) prime-boost regimens were assessed in C57BL/6 mice. Homologous immunization with either the chimeric protein or coadministered antigens induced robust IgG responses against PvCSP and PvMSP1₁₉, although anti-PvMSP1₁₉ titers were lower in mice receiving the chimeric construct. Among heterologous strategies, protein priming followed by adenoviral boosting elicited the highest IgG titers against both antigens. The chimeric protein consistently induced elevated IgG1/IgG2c ratios under both homologous and heterologous regimens. Furthermore, the frequency of antigen-specific antibody-secreting cells in the bone marrow closely paralleled the observed humoral responses. Collectively, these findings demonstrate that the PvCSP-MSP1₁₉ chimeric protein is highly immunogenic and capable of inducing immune responses against distinct stages of the P. vivax life cycle, supporting its further development as a multistage malaria vaccine candidate.

PMID:
42826687
Bibliographic data and abstract were imported from PubMed on 03 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.