Identifying higher risk subgroups of health care workers for priority vaccination against COVID-19

Health care workers (HCWs) are exposed to high risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to close contact with infected patients in hospital. The objective of this study was to estimate the seroprevalence and to identify the exposure risk of various subgroups among HCWs to prioritize them for early vaccination.

This was a multicentre cross-sectional study conducted between 15 and 29 June 2020. A total of 987 HCWs were recruited randomly from two major tertiary-care hospitals of Peshawar city, Pakistan. The HCWs included doctors, nurses, paramedics and hospital support staff. The US Food and Drug Administration (FDA)-approved kit was used for the detection of SARS-CoV-2 antibodies.

Overall, 310 (31.4%) HCWs were seropositive for SARS-CoV-2 antibodies (95% confidence interval, CI: 28.5-34.4). Seroprevalence was higher in males (33.5%) and in age group 51-60 years (40.9%). Seropositivity increased with increasing age from 8.3% in age group ⩽20 to 40.9% in 51-60 years of age group (p < 0.05). The highest seroprevalence was identified in paramedical staff (42·5%, 95% CI: 36.6-48.6) followed by nursing staff (38·8%, 95% CI: 32.1-45.7). In logistic regression, being a male HCW led to higher risk of seropositivity (odds ratio, OR: 1.50, 95% CI: 1·06-2.13. p < 0.05) compared with female staff members. The odds of seropositivity was higher in nurses (OR: 3·47, 95% CI: 1.99-6.05. p < 0.01), paramedical staff (OR: 3·19, 95% CI: 1.93-5.28. p < 0.01) and hospital support staff (OR: 2·47, 95% CI: 1.29-4.7. p < 0.01) compared with consultants.

Overall, our results concluded that nursing and paramedical staff are at higher risk and should be vaccinated on priority.