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

• Published in: Frontiers in immunology Vol. 12; p. 766278
• Main Authors: Escobar, Alejandro, Reyes-López, Felipe E, Acevedo, Mónica L, Alonso-Palomares, Luis, Valiente-Echeverría, Fernando, Soto-Rifo, Ricardo, Portillo, Hugo, Gatica, Jimena, Flores, Ivan, Nova-Lamperti, Estefanía, Barrera-Avalos, Carlos, Bono, María Rosa, Vargas, Leonardo, Simon, Valeska, Leiva-Salcedo, Elias, Vial, Cecilia, Hormazabal, Juan, Cortes, Lina Jimena, Valdés, Daniel, Sandino, Ana M, Imarai, Mónica, Acuña-Castillo, Claudio
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 31.01.2022
• Subjects: Adult; Antibodies, Neutralizing - blood; Antibodies, Viral - blood; B-Lymphocytes - drug effects; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Biomarkers - blood; Chile; CoronaVac; COVID-19; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 Vaccines - administration & dosage; COVID-19 Vaccines - immunology; Female; Granzymes - metabolism; Healthy Volunteers; herd immunity; Humans; Immunity, Cellular - drug effects; Immunity, Humoral - drug effects; Immunization Schedule; Immunogenicity, Vaccine; Immunologic Memory - drug effects; Immunology; Interferon-gamma - metabolism; Male; Middle Aged; neutralizing antibodies; SARS-CoV-2; SARS-CoV-2 - immunology; Spike Glycoprotein, Coronavirus - immunology; Time Factors; Treatment Outcome; vaccine; Chile; COVID-19; herd immunity; SARS-CoV-2; vaccine; immunological memory; neutralizing antibodies; CoronaVac
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.766278

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.