An NPR investigation has identified more than 30 medical practices in more than a dozen states promoting unproven claims that the drug thymosin alpha-1, which is administered via injection, can prevent or treat COVID-19.

A photo illustration show a syringe. Argentina was selected to test a vaccine against COVID-19, it is estimated that the clinical phases will begin in August. (Photo illustration by Carol Smiljan/NurPhoto via Getty Images)