Clinical Characteristics, Breakthrough Infections, and Reinfections with SARS CoV-2 among Healthcare Workers in the Omicron Wave

Introduction: A global increase in infections was noted with the emergence of the Omicron variant, which exhibited immune evasion capabilities against previous infections or vaccinations. Healthcare workers (HCWs) faced increased risk from occupational exposure. This study aimed to investigate the clinical characteristics, reinfection rates, and breakthrough infections among HCWs during the Omicron wave. Methods: A total of 312 HCWs who tested positive for SARS-CoV-2 during the Omicron wave (January 1 February 22, 2022) were enrolled in the study after providing consent. Participating HCWs completed a questionnaire to provide details on demographics, symptoms at testing, comorbidities, vaccination status, and prior COVID-19 infection history. Clinical outcomes were also recorded. Cases of reinfection and breakthrough infection were identified. Results: The median age of HCWs in the study was 32.9 years. The frequency of infection was higher in females (56.7%) and among the professional categories, doctors (58.3%) accounted for the majority of cases. Symptomatic infection was prevalent in 89.7% of cases, with most being mild. Out of 312 healthcare workers, 265 (84.9%) received at least one dose of the Covishield vaccine. Of these, 206 (77.7%) received two doses, and 41 (15.5% of vaccinated HCWs) also received a booster dose. 153 (49.1%) had a history of prior SARS-CoV-2 infection. Hospitalization was required for three unvaccinated HCWs with comorbidities, while no vaccinated HCWs required hospitalization; no deaths occurred. Conclusions: The study found that 312 healthcare workers were infected during the Omicron wave. Vaccination and prior infection did not provide complete protection against the Omicron variant. Consequently, breakthrough infections and reinfections were observed with notable frequency during this period.