Healthcare workers in Britain and Thailand have started taking part in a trial to determine whether two anti-malarial drugs can prevent COVID-19, including one that US President Donald Trump says he has been taking.

The study, involving more than 40,000 healthcare workers across Europe, Africa, Asia and South America, seeks to determine whether chloroquine and hydroxychloroquine could play a role in the fight against the novel coronavirus.

Demand for hydroxychloroquine surged after Trump touted it in early April. He said this week he was now taking it as a preventive medicine against the virus despite medical warnings about its use. 

Source:Aljazeera