Dr Phawin Keskool, a professor at Siriraj Hospital’s Faculty of Medicine, said that povidone iodine was an antiseptic, and was capable of reducing the possibility of infection, sepsis, or putrefaction. 
However, he explained that the antiseptic substance cannot totally sterilise viruses or bacteria, only reduce their numbers to prevent humans from the risk of contracting them. 
The doctor, however, clarified that using povidone iodine products, whether inside or outside human bodies, cannot kill the coronavirus.

Povidone iodine can help, but not offer immunity to Covid-19

Moistening one's throat with povidone iodine cannot prevent Covid-19 but it can reduce the infection rate, a medical expert said.