There are currently no approved treatments, or preventive vaccines for COVID-19, the highly contagious, sometimes deadly respiratory illness caused by the new coronavirus. Researchers are studying existing treatments and working on experimental ones, but most current patients receive only supportive care such as breathing assistance.

Hydroxychloroquine, a malaria drug, is among the medications that are being tested, as a potential treatment for patients with the disease. Earlier this week, the American Society of Health-System Pharmacists (ASHP), which maintains a list of drug shortages, said hydroxychloroquine was in shortage.

“Chloroquine has demonstrated toxicity in certain patients,” Dinesh Dua, chairman of the Pharmaceuticals Export Promotion Council of India, told Reuters. “You have to tread with caution because there is no comprehensive data to prove it works.”

The group said India faced no shortages of the drug but they warned companies were facing acute shortages of staff to run operations.

Late on Tuesday, India ordered a 21-day lockdown of its 1.3 billion people to try to protect the world’s second most populous country from the fast-spreading coronavirus.

“It is impossible to maintain operations due to lockdown, because employees don’t want to come,” Dua said.

India has already banned export of all ventilators and sanitizers and personal protection equipment such as masks and clothing to contain the outbreak that has so far infected more than 550 people and claimed close to a dozen lives in the country.

The ban comes after India, the world’s largest supplier of generic drugs, this month restricted the export of 26 pharmaceutical ingredients and the medicines made from them, including Paracetamol, a common pain reliever also sold as acetaminophen, as the coronavirus outbreak plays havoc with supply chains. Some of those restrictions have since been relaxed.

For an interactive graphic tracking global spread of coronavirus: open https://tmsnrt.rs/3aIRuz7 in an external browser. (Reporting by Neha Dasgupta; Editing by Euan Rocha and Edwina Gibbs)