SARS-CoV-2 infection in properly vaccinated healthcare workers

Porto, Miriam Hernández; Castro, Beatriz; Diaz, Zaida; Pedroso, Yanet; Ramos, María José; Lecuona, María

Background BNT162b2 mRNA Covid-19 vaccine has shown an optimal protection for population. However the development of SARS-CoV-2 infection has been reported in persons, who have received one or both doses of vaccine. The Hospital Universitario de Canarias began to vaccinate to healthcare workers on Febraury, 2021. We have detected several asymptomatic cases of SARS-CoV2 infections in healthcare workers. Methods We performed PCR on health staff at our Centre after the two doses of vaccination, which were realized by screening in close contact with positive cases, new addition to the hospital or a requirement before traveling to another region in the country. In positive cases we determined the quantitative IgG (post-vaccine Spike1-RBD and nucleocapside) and IgM (Spike1-RBD). Results We detected five cases of SARS-CoV-2 infection in properly vaccinated healthcare workers after 15 days of the second dose vaccine. All cases had high Cts values and were asymptomatics. The Post-vaccine IgG level was between 778.9-4,420.7 BAU/ml. Conclusions This communication reflects how vaccination protected healthcare workers from disease; however, it remains to be analyzed the transmissibility of virus after vaccination. We consider the importance of preserving, at the moment, prevention measures against SARS-CoV-2 virus in the hospital environment, mainly by vaccinated healthcare staff.