The two pills by the US pharma giants represent a potentially groundbreaking step in the fight against coronavirus as studies show they cut the risk of hospitalisation and death in high-risk patients.

The European Medicines Agency (EMA) said that while the Merck pill was not yet approved, it had "issued advice" so that individual countries in the 27-nation EU could decide whether to use it in case of a surge in infections.

"The medicine, which is currently not authorised in the EU, can be used to treat adults with Covid-19 who do not require supplemental oxygen and who are at increased risk of developing severe Covid-19," the EMA said in a statement.

"EMA issued this advice to support national authorities who may decide on possible early use of the medicine prior to marketing authorisation, for example in emergency use settings, in light of rising rates of infection and deaths due to Covid-19 across the EU."

The Merck pill should not be used by pregnant women or women who are not using contraception and could get pregnant, the EMA said.

"These recommendations are given as laboratory studies in animals have shown that high doses of (the Merck pill) can impact the growth and development of the foetus," it added.

The pill should be given as soon as possible after Covid symptoms start, at the latest within five days. It should then be taken for five days, the EMA said.

The Amsterdam-based watchdog says it hopes to decide on formal approval for the Merck pill, also known as molnupiravir, by the end of the year.

eNCA