Air cleaners and HEPA filters, when used appropriately, can help decrease airborne pollutants such as viruses in a building or small area. However, air cleaning or filtration alone will not protect humans against COVID-19. Filtration can be part of a plan to decrease the possibility for COVID-19 airborne transmission indoors when used in conjunction with other best practices suggested by the CDC and other public health organizations, such as social distance and mask wearing.