Estimated virus half-life was more than 24 hours at 10 degrees C (50 degrees F) and 40 percent relative humidity, but only 90 minutes at 27 degrees C (80 degrees F) and 65 percent relative humidity. Indeed, a study conducted in New South Wales, Australia, demonstrates an inverse relationship between relative humidity and transmission of SARS-CoV-2. We are requesting that the WHO produce clear guidelines on the minimum lower limit of air humidity in buildings. We recommend maintaining relative humidity between 40 to 60 percent to maximize the benefits of humidity but not the drawbacks of too much humidity that promote mold growth. Indoor air control is the next frontier to improve human health and reduce transmission of various types of viruses, including SARS-COV-2.