To the Editor Opel et al1 proposed 9 criteria to consider when evaluating a coronavirus disease 2019 (COVID-19) vaccine should be mandatory in school immunization programs. Two of these deserve further reflection.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in December Wuhan, the capital of China’s Hubei province and has rapidly spread all over world. Until August 2020, >25 million cases SARS-CoV-2 infection had been confirmed worldwide, causing >800,000 deaths. This named World Health Organization (WHO) as COVID-19...