Twitter has removed a tweet by Iran's supreme leader Ayatollah Ali Khamenei suggesting coronavirus vaccines made in the United States and Britain are "untrustworthy", saying the post violated its rules.

Brigitte Macron, the wife of French President Emmanuel Macron, caught the coronavirus over Christmas, her office said Saturday, confirming press reports.

More than three quarters of people hospitalised with Covid-19 still suffered from at least one symptom after six months, according to a study published Saturday that scientists said shows the need for further investigation into lingering coronavirus effects.

Lebanon on Friday reported 5,440 fresh coronavirus cases, a new record high of daily infections for the small country, which registered 4,774 cases on Thursday.

The harrowing tally comes on the second day of a 25-day lockdown aimed at reining in a major spike in virus cases.

Iran's supreme leader on Friday banned the import of American and British-produced vaccines against Covid-19, saying they were "completely untrustworthy."

"Importing vaccines made in the U.S. or the UK is prohibited," Ayatollah Ali Khamenei said in a tweet, accompanied by the hashtag #CoronaVaccine.

Britain on Friday reported a record 1,325 deaths over a 24 period from people testing positive for coronavirus, as a surge in cases piled pressure on overstretched health services, forcing London to declare a major incident.

The EU has struck a deal to double its supply of BioNTech/Pfizer vaccine against Covid-19 to a total of 600 million doses, European Commission chief Ursula von der Leyen said on Friday.

New research suggests that Pfizer's COVID-19 vaccine can protect against a mutation found in two highly contagious variants of the coronavirus that erupted in Britain and South Africa.

Australia's third-largest city was headed into another lockdown Friday and nationwide restrictions on international arrivals were being tightened, after a cleaner at a quarantine hotel contracted the highly infectious UK strain of Covid-19.

Countries in Asia stepped up their fight against the coronavirus on Thursday to suppress a contagion they had previously tamed, as warnings grew in Europe over a new fast-spreading variant.