Abstract
The disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Coronavirus Disease-2019 (COVID-19), is a global emergency. The first case of COVID-19 was confirmed in Japan in January 2020, a second outbreak of infection occurred in mid-March and a third peak at the beginning of August. The COVID-19 phenotype was milder in Japan than in other countries, although the restrictive measures applied in the country have not been as strict as in other places. Factors related to a possible reduced susceptibility to the pulmonary manifestations of SARS-CoV-2 may have contributed to better outcomes and lower mortality in Japan.