People on blood thinners such as aspirin may take Covid-19 vaccines without hesitation, Balram Bhargava, the head of India’s health research department, said on Thursday.

He said the country’s drug regulatory authority would clarify this soon.

Bhargava’s assurance is relevant to people prioritised for Covid-19 vaccination but taking blood thinners such as aspirin or clopidogrel. Doctors say a significant proportion of the elderly are likely to be on either of these two drugs.

The fact sheets for the two Covid-19 vaccines currently used in India — Covishield and Covaxin — flag blood thinners. The Covaxin document says people “on a blood thinner” should not receive Covaxin, while the Covishield document says people on a blood thinner should mention this to their healthcare providers before they receive Covishield.

Bhargava, director-general of the Indian Council of Medical Research, said both companies have written to the Drugs Controller-General of India (DCGI) about changing these points on the fact sheets.

He said there are two classes of blood thinners — anti-platelet medications such as aspirin or clopidogrel, and anti-coagulant medications such as heparin. “Aspirin and clopidogrel — (they) are not a problem at all,” Bhargava said.

People who are on anti-coagulants have a higher tendency to bleed. “The only worry is that there can be a local hematoma or a local swelling at the site of the injection,” Bhargava said.

He said people on anti-coagulants may stop the medication for one or two days before receiving the vaccination. These points, Bhargava said, will be incorporated into the corrected fact sheets once approved by the DCGI.