Primary series COVID-19 vaccine effectiveness among health care workers in the country of Georgia, March–December 2021

• DOI: 10.1371/journal.pone.0307805
• Publication Date: 2024-09-06T17:35:22Z
• Authors: Mark A. Katz; Madelyn Yiseth Ro...; Giorgi Chakhunash...; Nazibrola Chitadze; Caleb L. Ward; C. Jason McKnight; Héloïse Lucaccioni; Iris Finci; Tamila Zardiashvili; Richard Pebody; Esther Kissling; Lia Sanodze
• Keywords: Pandemic

Background Healthcare workers (HCWs) have suffered considerable morbidity and mortality during the COVID-19 pandemic. Few data on vaccine effectiveness (VE) are available from middle-income countries in WHO European Region. We evaluated primary series VE against laboratory-confirmed among HCWs Georgia. Methods six hospitals Georgia were invited to enroll a prospective cohort study conducted March 19–December 5, 2021. Participants completed weekly symptom questionnaires. Symptomatic tested by RT-PCR and/or rapid antigen test (RAT), participants routinely for SARS-CoV-2 or RAT, regardless of symptoms. Serology was collected at enrolment, quarterly thereafter, electrochemiluminescence immunoassay antibodies. defined vaccination as two doses received ≥14 days before onset. estimated (1-hazard ratio)*100 using Cox proportional hazards model with status time-varying covariate. Estimates adjusted potential confounders that changed estimate more than 5%, according change-in-estimate approach. Results Overall, 1561/3849 (41%) eligible enrolled included analysis. The median age 40 (IQR: 30–53), 1318 (84%) female, 1003 (64%) had laboratory evidence prior SARS-Cov-2 infection. At 1300 (83%) unvaccinated; By end, 1082 (62%) (69% BNT162b2 (Pfizer-BioNTech); 22% BBIBP-CorV (Sinopharm); 9% other). During period, 191(12%) new PCR- RAT-confirmed symptomatic RAT- confirmed infection 58% (95%CI: 41; 70) all vaccinations, 68% 51; 79) BNT162b2, 40% 1; 64) vaccines. Among previously infected HCWs, 11; 80). medically attended 52% 28; 68), hospitalization 69% (95% CI: 36; 85). period predominant Delta variant circulation (July-December 2021), 30; 66). Conclusions Primary effective preventing most whom previous infection, mainly circulation. Our results support utility series, importance increasing coverage, even individuals.