Zika Virus Neutralizing Antibody Responses Elicited by Vaccination or Infection

Résumé fourni par la source

Background: Zika virus (ZIKV) emergence in 2015-2016 was characterized by high attack rates and a wave of Congenital Zika Syndrome cases that affected several countries in the Americas. The sudden drop in virus transmission in the following years and the lack of a reliable correlate of protection have hampered the development of vaccines. ZIKV neutralizing antibodies (nAbs) responses to natural ZIKV infection provide insights into the potential efficacy of vaccine candidates. Methods: In this study, we compared anti-ZIKV nAb responses generated by a ZIKV vaccine (TAK-426), to those elicited by natural ZIKV infection in participants from diverse geographic areas using the same neutralizing antibody assay. Results: Those with a ZIKV infection (inapparent or symptomatic) exhibited higher levels of ZIKV nAbs, than TAK-426 vaccine recipients at all time points. The differences were less pronounced 1 month after TAK-426 dose 2. ZIKV nAb titers in vaccinated recipients were above the calculated threshold of protection at 1 month post-dose 2 for flavivirus (FV)-naive participants and at 1 and 6 months post-dose 2 for FV-primed participants. The kinetics of ZIKV nAbs were similar for both the natural infection and vaccination groups, exhibiting a peak, decline, and stabilization pattern; however, vaccine non-inferiority was not demonstrated. Conclusions: Our findings suggest that nAbs evoked by the current phase 1 formulation and dosage of TAK-426 may not protect against a ZIKV infection in endemic countries and that a booster dose should be further evaluated.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.