Asthma leads to 3,500 deaths and 1.6 million emergency-room visits a year in the United States, according to the Centers for Disease Control and Prevention. Kaiser San Diego's chief of emergency medicine estimates, though, that there has been a decline of at least 30% in asthma-related emergency-room visits during the COVID-19 outbreak. And this is being seen nationwide. According to a Brigham and Women’s Hospital study,aAsthma attacks among Black and Latino patients dropped more than 40% during the pandemic. Respiratory viruses like colds and the flu are known triggers of asthma attacks...