Effect of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) mRNA vaccination in healthcare workers with high-risk coronavirus disease 2019 (COVID-19) exposure

Healthcare providers (HCPs) have experienced significant burden of disease throughout the coronavirus disease 2019 (COVID-19) pandemic.1,2 Infection prevention measures mitigated the significant initial work-related risk; however, many HCPs developed COVID-19 following exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2)–infected individuals at home or in the community.2,3 Healthcare systems have developed policies around SARS-CoV-2 testing, returning to work after infection, and high-risk exposures for their employees.4 At Nebraska Medicine, employees were asked to report any COVID-19 symptoms or exposures to the Employee Health Department for instructions on testing, quarantine, and isolation. The emergency use authorization of 2 messenger RNA (mRNA) vaccines—the BNT162b2 vaccine (Pfizer-BioNTech) and the mRNA-1273 vaccine (Moderna)—were critical events in the response to the pandemic.5,6 In clinical trials, both vaccines were shown to be very effective at preventing severe disease and hospitalization due to COVID-19; however, information regarding acquisition of infection with subsequent asymptomatic shedding of SARS-CoV-2 remain limited, particularly following known exposures to close contacts with COVID-19 cases.5,6 Therefore, we describe the incidence of SARS CoV-2 infection among vaccinated employees at our institution after a high-risk household exposure to a family member with COVID-19. Since December 18, 2020, Nebraska Medicine, a tertiary-care academic medical center in Omaha, Nebraska, has fully vaccinated 12,160 employees with 1 of the 2 available mRNA vaccines. Furthermore, 11 were able to physically distance away from the positive contact; 23 had 2 negative tests; and 2 had 3 or more negative tests. [...]5 employees tested positive: 3 employees were positive in the protocol and 2 were positive on entry testing.