The World Health Organization cautioned against major alarm over a new, highly infectious variant of the coronavirus that has emerged in Britain, saying this was a normal part of a pandemic’s evolution.

Countries across the globe shut their borders to Britain on Dec. 21 due to fears about a highly infectious new coronavirus strain, causing travel chaos and raising the prospect of food shortages days before Britain is set to leave the European Union.

The European Commission approved Aimmune Therapeutics Inc.’s Palforzia for the treatment of peanut allergy.

The United States is monitoring the new strain of Covid-19 emerging in the United Kingdom, with U.S. officials unclear whether the mutated variant had made its way to America.

Global coronavirus infections surpassed the 75 million mark on Dec. 19, according to a Reuters tally, as several nations around the world begin vaccinating against the virus.

Oxford University’s Covid-19 vaccine candidate has a better immune response when a two full-dose regime is used rather than a full-dose followed by a half-dose booster, the university said, citing data from early trials.

The European Union is on course to approve its first Covid-19 vaccine before Christmas after the EU drug regulator brought forward a deadline for review following the start of immunization campaigns in the United States and Britain.

Top U.S. Food and Drug Administration regulators said most Americans with allergies should be safe to receive the Covid-19 vaccine developed by Pfizer Inc. and Germany’s Biotech SE.

The United States authorized the use of Pfizer Inc’s Covid-19 vaccine on Dec. 11, with the first inoculations expected within days, marking a turning point in a country where the pandemic has killed more than 295,000 people.

The chief executive of Germany’s BioNTech SE said the biggest challenge facing the company and partner Pfizer Inc. now that their Covid-19 vaccine is authorized for use in the United States will be to scale up manufacturing to meet huge demand.