Researchers at Duke University examined several types of face coverings — from cloth masks to bandanas to neck gaiters — to review their effectiveness of stopping large respiratory droplets. Determining the effectiveness of masks, they said,  "is a complex topic," in part, because "the infection pathways for COVID-19 are not yet fully understood and are complicated by many factors such as the route of transmission, correct fit and usage of masks, and environmental variables."

Nonetheless, several states, local governments, and businesses have implemented mask mandates to help slow the spread of the novel coronavirus, despite the lingering questions on the efficacy of homemade masks, which many Americans have embraced given the widespread call to reserve N95 masks for frontline medical workers.