Profile of COVID-19 breakthrough cases and its comparison with unvaccinated COVID-19 cases among healthcare workers in a tertiary care centre in North Kerala

BACKGROUND: Healthcare workers (HCWs) were the most vulnerable group during COVID-19 pandemic and had faced many challenges including high rate of breakthrough infections. AIMS: To study the incidence of reported breakthrough infections among HCWs in Government Medical College, Kozhikode and to compare profile of COVID-19 infection between fully vaccinated and unvaccinated COVID-19 positive HCWs. SETTINGS AND DESIGN: The research was conducted as a prospective study for a duration of 78 weeks from 1(st) of March 2020 through 31(st) of August 2021 in Government Medical College, Kozhikode. METHODS AND MATERIAL: The study was conducted among HCWs in a COVID-19 tertiary care institute. Real-time data were collected from 401 breakthrough cases and 390 unvaccinated COVID-19 positive HCWs through telephonic interviews. STATISTICAL ANALYSIS USED: Univariate analysis was done using frequency for categorical variables and mean and standard deviation for quantitative variables. Chi-square test was used to find out statistical significance. RESULTS: Incidence of breakthrough infection was found to be 5.62% with 43.3% being asymptomatic. Fever was the most predominant symptom (62.5%). None of the breakthrough cases developed complication requiring intensive care (ICU). There was a reduction in incidence of acute post-COVID-19 syndrome in vaccinated group (17.45%) compared to unvaccinated group (57.2%). CONCLUSIONS: COVID-19 vaccination plays a key role in preventing severity, complication, and ICU admissions in COVID-19 infection. Incidence of post-COVID-19 syndrome is also less among fully vaccinated compared to unvaccinated individuals.