It was thought to be the end of a monthslong COVID-19 controversy in Japan.

The National Institute of Infectious Diseases announced its determination late last month that the coronavirus spreads when one inhales virus-laden aerosols, or tiny particles mixed with water floating in the air for an extended period of time, confirming a view long held by much of the scientific community.

The NIID's March 28 statement said the virus is mainly transmitted three ways: breathing in virus-containing aerosols traveling over long distances; having relatively large droplets land on the mouth, nose or eyes through a sneeze or cough; and touching the eyes, nose or mouth with virus-infected hands. Previous reports issued by the health ministry-affiliated institute ruled out the possibility of aerosol transmission and referred only to the other two.