We aimed to assess risk of COVID-19 infection & seroprotection status in healthcare workers (HCWs) in both hospital and community settings following an intensive vaccination drive in India.

Tertiary Care Hospital

We surveyed COVID-19 exposure risk, personal protective equipment (PPE) compliance, vaccination status, mental health & COVID-19 infection rate across different HCW cadres. Elecsys® test for COVID-19 spike (Anti-SARS-CoV-2S; ACOVs) and nucleocapsid (Anti-SARS-CoV-2; ACOV) responses following vaccination and/or COVID-19 infection were measured in a stratified sample of 386 HCW.

We enrolled 945 HCWs (60.6% male, age 35.9 ± 9.8 years, 352 nurses, 211 doctors, 248 paramedics & 134 support staff). Hospital PPE compliance was 90.8%. Vaccination coverage was 891/945 (94.3%). ACOVs neutralizing antibody was reactive in 381/386 (98.7%). ACOVs titer (U/ml) was higher in the post-COVID-19 infection group (N =269; 242.1 ± 35.7 U/ml) than in the post-vaccine or never infected subgroup (N = 115, 204.1 ± 81.3 U/ml). RT PCR + COVID-19 infections were documented in 224/945 (23.7%) and 6 HCWs had disease of moderate severity, with no deaths. However, 232/386 (60.1%) of HCWs tested positive for nucleocapsid ACOV antibody, suggesting undocumented or subclinical COVID-19 infection. On multivariate logistic regression, only female gender [aOR 1.79, 95% CI 1.07–3.0, P = .025] and COVID-19 family contact [aOR 5.1, 95% CI 3.84–9.5, P < .001] were predictors of risk of developing COVID-19 infection, independent of association with patient-related exposure.

Our HCWs were PPE compliant and vaccine motivated, with immunization coverage of 94.3% and seroprotection rate of 98.7%. There was no relationship between HCW COVID-19 infection to exposure characteristics in the hospital. Vaccination reduced disease severity and prevented death in HCW.