Effectiveness of mRNA Covid-19 vaccine in healthcare workers

Dear Editor,

We would like to discuss on publication entitled “Effectiveness of the BNT162b2 mRNA Covid-19 vaccine in Spanish healthcare workers.”¹ 1. Núñez López et al. concluded that “BNT162b2 mRNA COVID-19 vaccine is highly effective in Spanish HCW.”¹ We agree that mRNA vaccine might be useful. However, it might be difficult to say that the vaccine is highly effective. Without laboratory investigation on protective antibody titer, the data on incidence of disease might be only indirect clinical evidence. The infection incidence might be associated with many factors including situation of disease epidemic, which is different at different time period. Without an investigation, it is not possible to detect the silent asymptomatic infection among HCW. In a setting the zero COVID-19 case in hospital, the positivity among HCW is still possible.²

Conflict of interest

None.