The Asthma and Allergy Foundation of America (AAFA) has issued a warning about a concerning new social media trend in which people are breathing in hydrogen peroxide through nebulizers to treat or prevent COVID-19. In a Tuesday blog post, the AAFA said that the "dangerous trend" was circulating on Facebook, Twitter and TikTok. "DO NOT put hydrogen peroxide into your nebulizer and breathe it in. This is dangerous!" the association said.