Version 1
: Received: 3 October 2023 / Approved: 4 October 2023 / Online: 4 October 2023 (09:31:38 CEST)
Version 2
: Received: 5 October 2023 / Approved: 5 October 2023 / Online: 7 October 2023 (03:27:13 CEST)
How to cite:
Katz, M.A.; Castro, M.Y.R.; Chakhunashvili, G.; Chitadze, N.; Ward, C.; McKnight, C.J.; Lucaccioni, H.; Finci, I.; Zardiashvili, T.; Pebody, R.; Kissling, E.; Sanodze, L. Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in the Country of Georgia, March–December 2021. Preprints2023, 2023100224. https://doi.org/10.20944/preprints202310.0224.v2
Katz, M.A.; Castro, M.Y.R.; Chakhunashvili, G.; Chitadze, N.; Ward, C.; McKnight, C.J.; Lucaccioni, H.; Finci, I.; Zardiashvili, T.; Pebody, R.; Kissling, E.; Sanodze, L. Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in the Country of Georgia, March–December 2021. Preprints 2023, 2023100224. https://doi.org/10.20944/preprints202310.0224.v2
Katz, M.A.; Castro, M.Y.R.; Chakhunashvili, G.; Chitadze, N.; Ward, C.; McKnight, C.J.; Lucaccioni, H.; Finci, I.; Zardiashvili, T.; Pebody, R.; Kissling, E.; Sanodze, L. Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in the Country of Georgia, March–December 2021. Preprints2023, 2023100224. https://doi.org/10.20944/preprints202310.0224.v2
APA Style
Katz, M.A., Castro, M.Y.R., Chakhunashvili, G., Chitadze, N., Ward, C., McKnight, C.J., Lucaccioni, H., Finci, I., Zardiashvili, T., Pebody, R., Kissling, E., & Sanodze, L. (2023). Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in the Country of Georgia, March–December 2021. Preprints. https://doi.org/10.20944/preprints202310.0224.v2
Chicago/Turabian Style
Katz, M.A., Esther Kissling and Lia Sanodze. 2023 "Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in the Country of Georgia, March–December 2021" Preprints. https://doi.org/10.20944/preprints202310.0224.v2
Abstract
Background Healthcare workers (HCWs) have suffered considerable morbidity and mortality during the COVID-19 pandemic. Few data on COVID-19 vaccine effectiveness (VE) are available from middle-income countries in Europe. We evaluated primary series COVID-19 VE against laboratory-confirmed COVID-19 among HCWs in Georgia. Methods HCWs in six hospitals in Georgia were invited to enroll in a prospective cohort study conducted during March 19–December 5, 2021. Participants completed weekly symptom questionnaires. Symptomatic HCWs were tested by RT-PCR and/or rapid antigen test (RAT), and participants were routinely tested for SARS-CoV-2 by RT-PCR or RAT, regardless of symptoms. Serology was collected at enrolment, and quarterly thereafter, and tested by electrochemiluminescence immunoassay for SARS-CoV-2 antibodies. We defined primary series vaccination as two doses of COVID-19 vaccine received ≥14 days before symptom onset. We estimated VE as (1-hazard ratio)*100 using a Cox proportional hazards model with vaccination status as a time-varying covariate. Estimates were adjusted by potential confounders that changed the VE estimate by more than 5%, according to the change-in-estimate approach. Results Overall, 1561/3849 (41%) eligible HCWs enrolled and were included in the analysis. The median age was 40 (IQR: 30-53), 1318 (84%) were female, and 1003 (64%) had laboratory evidence of prior SARS-Cov-2 infection. At enrolment, 1300 (83%) were unvaccinated; By study end, 1082 (62%) had completed a primary vaccine series (69% BNT162b2 (Pfizer-BioNTech); 22% BBIBP-CorV (Sinopharm); 9% other). During the study period, 191(12%) participants had a new PCR- or RAT-confirmed symptomatic SARS-CoV-2 infection. VEa gainst PCR- or RAT- confirmed symptomatic SARS-CoV-2 infection was 58 (95%CI: 41; 70) for all primary series vaccinations, 68% (95%CI: 51; 79) for BNT162b2, and 40% (95%CI: 1; 64) for BBIBP-CorV vaccines. Among previously infected HCWs, VE was 58% (95%CI: 11; 80). VE against medically attended COVID-19 was 52% (95%CI: 28; 68), and VE against hospitalization was 69% (95% CI: 36; 85). During the period of predominant Delta variant circulation (July-December 2021), VE against symptomatic COVID-19 was 52% (95%CI: 30; 66). Conclusions Primary series vaccination with BNT162b2 and BBIBP-CorV was effective at preventing COVID-19 among HCWs, most of whom had previous infection, during a period of mainly Delta circulation. Our results support the utility of COVID-19 primary vaccine series, and the importance of increasing coverage, even among previously infected individuals.
Public Health and Healthcare, Public, Environmental and Occupational Health
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
7 October 2023
Commenter:
Mark Katz
Commenter's Conflict of Interests:
Author
Comment:
There are some minor changes to the nomenclature of the European Regional Office of WHO, we added an additional reference in the introduction section, and we corrected an email address of one of the co-authors.
Commenter: Mark Katz
Commenter's Conflict of Interests: Author