Companies racing to find treatments for the novel coronavirus, which has infected close to 100,000 people, are turning to artificial intelligence to speed up their drug-discovery efforts.

Health authorities have been searching for a drug to treat Covid-19 since shortly after the virus that causes the illness emerged in China late last year. There are no approved treatments or vaccines, although an antiviral drug from Gilead Sciences Inc. began clinical tests in the U.S. last week. Clinical trial enrollment is also under way...