Pharmaceutical company Pfizer said it has begun a large-scale clinical trial of a drug to avoid COVID-19 in those exposed to the virus.
Tests for oral antibiotic will include 2,660 healthy adult participants living in the same family with someone who is infected with COVID-19.
The Pfizer company is also studying the drug in people who are already infected with COVID-19, but who have not yet developed serious symptoms.
“If successful, we believe this therapy can help stop the virus early, before it has had a chance to spread widely,” Pfizer chief scientific officer Dr Mikael Dolsten said in a statement.
The drug aims to block a key enzyme that the virus needs to multiply. If it works, scientists believe it will only be effective in the early stages of infection. When COVID-19 has become a serious disease, the virus has meanwhile stopped spreading and patients are mainly affected by the overactive immune response.