Evaluation of the Immune Response Induced by CoronaVac 28-Day Schedule Vaccination in a Healthy Population Group

<jats:p>CoronaVac vaccine from Sinovac Life Science is currently being used in several countries. In Chile, the effectiveness of preventing hospitalization is higher than 80% with a vaccination schedule. However, to date, there are no data about immune response induction or specific memory. For this reason, we recruited 15 volunteers without previous suspected/diagnosed COVID-19 and with negative PCR over time to evaluate the immune response to CoronaVac 28 and 90 days after the second immunization (dpi). The CoronaVac administration induces total and neutralizing anti-spike antibodies in all vaccinated volunteers at 28 and 90 dpi. Furthermore, using ELISpot analysis to assay cellular immune responses against SARS-CoV-2 spike protein, we found an increase in IFN-gamma- and Granzyme B-producing cells in vaccinated volunteers at 28 and 90 dpi. Together, our results indicate that CoronaVac induces a robust humoral immune response and cellular immune memory of at least 90 dpi.</jats:p>

Escobar, A., Reyes-López, F. E., Acevedo, M. L., Alonso-Palomares, L., Valiente-Echeverría, F., Soto-Rifo, R., Portillo, H., Gatica, J., Flores, I., Nova-Lamperti, E., Barrera-Avalos, C., Bono, M. R., Vargas, L., Simon, V., Leiva-Salcedo, E., Vial, C., Hormazabal, J., Cortes, L. J., Valdés, D., … Acuña-Castillo, C. (2022). Evaluation of the immune response induced by coronavac 28-day schedule vaccination in a healthy population group. Frontiers in Immunology, 12, 766278. https://doi.org/10.3389/fimmu.2021.766278