France on Friday recommended that people who have already recovered from Covid-19 receive a single vaccine dose, becoming the first country to issue such advice.

All three Covid-19 vaccines approved for use in the European Union are administered in the form of two doses, delivered several weeks apart. 

This is because clinical trials showed that immunity against the disease was significantly higher after individuals received two shots.

France's public health authority said Friday however that people who had already been infected with Covid-19 develop an immune response similar to that bestowed by a vaccine dose, and that a single dose after infection would likely suffice.

"A single vaccine dose will also play the role of reminding" their immune system how to fight Covid-19, it said.

The authority recommended a gap of between three and six months after infection before individuals who had recovered from Covid-19 receive a jab.

"At the moment no country has clearly positioned itself in terms of a sole vaccination dose for people who have already contracted Covid-19," it said.

France has accelerated its vaccination programme in recent weeks but it is still in its infancy. 

As of Thursday, over 2.1 million people had received at least one vaccine dose, with almost 535,800 having already received two.

At least 3.4 million people have had confirmed Covid-19 infections in France, although there are likely to have been far more given the relative lack of accessible testing during the pandemic's first wave.

Two recent US studies suggest that a single vaccine dose may work in individuals who have already recovered from Covid-19.

One paper said that immunity in individuals who had had Covid-19 and then received a single vaccine dose "is equal to or even exceeds" that of people who have not had Covid-19 but received two vaccine doses.

A vaccine still in development by Johnson & Johnson works with a single dose, but it is yet to receive emergency use authorisation from EU and US regulators.