Immunization and SARS-CoV-2 antibody seroprevalence in a country with high vaccination coverage: Lessons from Chile
Date
2022
Type:
Article
item.page.extent
11 p.
item.page.accessRights
Acceso abierto
item.contributor.advisor
ORCID:
Journal Title
Journal ISSN
Volume Title
Publisher
item.page.isbn
item.page.issn
item.page.issne
item.page.doiurl
item.page.other
item.page.references
Abstract
Objective: Chile is among the most successful nations worldwide in COVID-19 vaccine rollout. By December 31st, 2021, 84.1% of the population was fully vaccinated, and 56.1% received booster doses using DIFFERENT TYPES OF COVID-19 VACCINES. In this context, we aimed to estimate the anti-SARSCoV-2 antibodies following the infection and vaccination campaign.
Study design: Population-based cross-sectional serosurvey based on a representative sample of the cities of Santiago, Coquimbo/La Serena, and Talca used in a previous study.
Methods: We selected the participants using a three-stage stratified sampling. They were blood-sampled on-site and answered a questionnaire regarding COVID-19-associated variables and vaccination antecedents using Wantai SARS-CoV-2 Ab ELISA to determine seroprevalence. This research followed the generic protocol of World Health Organization Unity studies.
Results: We recruited 2,198 individuals aged 7-93 between October 5th and November 25th, 2021. In our sample, 2,132 individuals received COVID-19 vaccinations (97%); 67 (3.1%) received one dose; 2,065 (93.9%) received the complete scheme; and 936 received the booster jab (42.6%). Antibody seroprevalence reached 97.3%, ranging from 40.9% among those not vaccinated to 99.8% in those with booster doses (OR=674.6, 154.8-2938.5). SARS-CoV-2 antibodies were associated with vaccination, previous COVID-19 diagnosis, age group, and city of residence. In contrast, we found no significant differences in the type of vaccine used, education, nationality, or type of health insurance.
Conclusion: We found a seroprevalence close to 100% in the population aged seven years and older, primarily due to the successful vaccination program, which has a strong emphasis on universal access.
Description
item.page.coverage.spatial
item.page.sponsorship
Citation
Aguilera, X., González, C., Apablaza, M., Rubilar, P., Icaza, G., Ramírez-Santana, M., ... & Vial, P. (2022). Immunization and SARS-CoV-2 antibody seroprevalence in a country with high vaccination coverage: Lessons from Chile. Vaccines, 10(7), 1002
Keywords
COVID-19, Vaccine coverage, Sinovac CoronaVac, BNT162b2, AZD1222, Ad5-nCoV, cross sectional, population-based, Santiago, Talca, Coquimbo, La Serena, ELISA, sero-survey, Vaccine coverage, Sinovac CoronaVac, BNT162b2, AZD1222, Ad5-nCoV, Cross sectional, Population-based, ELISA, Sero-survey, Santiago, Talca, Coquimbo, La Serena