An anti-malarial drug widely used in Africa in the 1980s and 1990s has been found to be effective on coronavirus patients, according to China's Ministry of Science and Technology.Chloroquine phosphate has been "unanimously" approved by experts in China to be used in the fight against the deadly Covid-19 virus, the state-run China Global Television Network reports.The drug proved effective at treating and also preventing malaria for decades before malarial parasites developed resistance to it.Xinhua, the state-run news agency, also reports that chloroquine has been used in clinical trials in more than 10 hospitals in China's capital, Beijing, and two other provinces and "has shown fairly good efficacy".