SARS-CoV-2 Vaccine Breakthrough Reinfections in Fully Vaccinated Healthcare Workers in Davao City, Philippines: A Retrospective Cohort Study
Year: 2025
Type: article
Study design: Observational Study
Abstract: Background: Breakthrough infections (BTIs) continue to occur among healthcare workers (HCWs) despite full COVID-19 vaccination, raising concerns about ongoing vulnerability in this high-risk group. In addition to initial BTIs, breakthrough reinfections (BTRs) have emerged as a challenge, with some HCWs experiencing multiple episodes of infection after vaccination. This study investigated the factors influencing breakthrough infection and reinfection rates among HCWs between January 2021 and December 2022 in Davao City, Philippines. Methods: This retrospective cohort study was conducted using secondary data from the Davao City Epidemiological Surveillance Unit, approved by the Department of Health. This study included 1011 fully vaccinated HCWs from various congressional districts. Results: BTI was observed in all HCWs included in the study. However, BTRs varied across occupational groups: medical technologists showed the highest reinfection rate (22.37%), followed by physicians (13.48%), and nurses/nurse aides (10.14%). Booster vaccination significantly reduced BTRs (5.83% vs. 11.18%, p = 0.0267). Occupation and institutional type were significant factors, with higher rates reported by physicians and in public hospitals (p = 0.0002 and p = 0.0041, respectively). The vaccine manufacturer, sex, age, and booster type showed no significant differences. Conclusion: These findings highlight the importance of targeted interventions for high-risk HCWs and emphasize the effectiveness of the booster vaccination.
Source: COVID
DOI: 10.3390/covid5070106
Institution: University of the Immaculate Conception
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,207
OpenAlex ID: W4412148751