Further questions on topics such as the possibility of asymptomatic transmission, the proportion of asymptomatic infections, stability of the virus in the environment and main risk groups [12] were partly answered as the pandemic progressed. Evidence of asymptomatic transmission was documented in several settings and a study based on an outbreak on a cruise ship determined the proportion of asymptomatic infections as 17.9% (95% credible interval: 15.5–20.2) [13]. Laboratory experiments provided data on the survival of the virus on different surfaces [14]. Aside from people older than 70 years, severe and fatal cases were seen particularly in men and people with hypertension, diabetes, underlying pulmonary diseases and in smokers. Children were shown to be infected with SARS-CoV-2 [15], however, the role of children in disease transmission still needs to be fully elucidated.