Breakthrough SARS-CoV-2 Infections after Vaccination in North Carolina

Area of Science:

• Epidemiology
• Infectious Diseases
• Vaccinology

Background:

• The COVID-19 pandemic necessitated widespread vaccination efforts.
• Understanding breakthrough infections is crucial for public health strategies.

Purpose of the Study:

• To determine the incidence of breakthrough SARS-CoV-2 infections.
• To identify risk factors associated with these infections in a fully vaccinated cohort.

Main Methods:

• Analysis of data from 15,808 fully vaccinated participants in the North Carolina COVID-19 Community Research Partnership.
• Time-to-event analysis to identify risk factors for breakthrough infection.

Main Results:

• 638 breakthrough infections were reported.
• Lower risk associated with older age, prior infection, mask use, and booster vaccination.
• Higher risk observed with BNT162b2/Ad26.COV2.S vaccines vs. mRNA-1273, rural/suburban vs. urban counties, and Delta/Omicron variants.

Conclusions:

• Incidence and risk factors for COVID-19 breakthrough infections vary.
• Vaccine type, geographic location, and circulating variants influence breakthrough risk.
• Boosters and preventative measures like mask-wearing remain important.