COVID-19: What you need to know about the coronavirus pandemic on 21 December

Confirmed cases of COVID-19 have passed 275.5 million globally, according to Johns Hopkins University. The number of confirmed deaths has now passed 5.36 million. More than 8.75 billion vaccination doses have been administered globally, according to Our World in Data.

India has recorded 200 cases of the Omicron coronavirus variant across 12 states, mostly in the western state of Maharashtra and the nation's capital New Delhi, the health ministry said on Tuesday. The country's tally of Omicron cases has nearly doubled within a week, but there have been no deaths reported so far.

New Zealand has postponed its phased border re-opening plans until the end of February over concerns of the rapid global spread of the Omicron variant of the coronavirus. The country had just started easing some of the world's toughest pandemic measures and its international border restrictions were to progressively loosen from January, with all foreign tourists allowed into the country from April.

Thailand will reinstate its mandatory COVID-19 quarantine for foreign visitors and scrap a quarantine waiver from Tuesday due to concerns over the spread of the Omicron variant of the coronavirus. The decision to halt the country's 'Test and Go' waiver means visitors will have to undergo hotel quarantine, which ranges between 7 to 10 days.

China reported 81 new confirmed coronavirus cases for 20 December, down from 102 a day earlier, its health authority said on Tuesday. Of the new infections, 57 were locally transmitted, according to a statement by the National Health Commission, compared with 37 a day earlier.

COVID-19 cases surged in New York City and across the US over the weekend, dashing hopes for a more normal holiday season, resurrecting restrictions and stretching the country's testing infrastructure ahead of holiday travel and gatherings.

The spike in COVID-19 cases is alarming public health officials, who fear an explosion of infections after the Christmas and New Year's holidays.

The Omicron variant now accounts for 73% of US COVID-19 infections based on sequencing data for the week ended on Saturday, the US Centers for Disease Control and Prevention said on Monday.

Lines for COVID-19 tests wrapped around the block in New York, Washington and other US cities over the weekend as people tried to find out if they were infected before celebrating the holidays with family.

The European Union has approved the use of Novavax's COVID-19 vaccine in people 18 years and older, giving a boost to the US company after long delays and paving the way for a fifth shot in the EU as the Omicron variant spreads.

Data from two large studies showed the vaccine has an efficacy of around 90%, the European Medicines Agency (EMA) said.

It is not clear yet, though, how Novavax performs against the Omicron variant, or whether a booster dose will be needed. Some early data has suggested that many two-dose vaccines do not work well against the variant while a third shot improves their efficacy.

Novavax said earlier this month it could begin manufacturing a vaccine tailored for Omicron in January.

COVID-19 infections have broken records in parts of Europe in recent weeks, with governments and researchers scrambling to bolster defences against the fast-spreading Omicron, prompting renewed curbs ahead of the Christmas holidays.