COVID-19: What you need to know about the coronavirus pandemic on 15 December

Confirmed cases of COVID-19 have passed 271.5 million globally, according to Johns Hopkins University. The number of confirmed deaths has passed 5.32 million. More than 8.55 billion vaccination doses have been administered globally, according to Our World in Data.

Poland's daily death toll from COVID-19 during the fourth wave of the pandemic has climbed to a record 660. "They are mainly unvaccinated people," government spokesman Piotr Muller said. "There is no doubt that Omicron is already in Poland ... Within the EU, we have free movement of people, so it is obvious that this mutation should be in Poland," Muller said.

The Netherlands will extend COVID-19 restrictions through the Christmas holidays, including the early closure of schools, Prime Minister Mark Rutte said on Tuesday. The rapid spread of the Omicron variant, which is making up roughly 1% of new infections, "is a reason to be concerned and to be cautious," Rutte said in televised comments.

South Korea warned on Wednesday it may reinstate stricter social distancing as it posted a record daily COVID-19 case tally due to a persistent spike in breakthrough infections among those vaccinated and serious cases. The Korea Disease Control and Prevention Agency (KDCA) posted 7,850 cases for Tuesday, with the number of patients in a serious condition also reaching a fresh high at 964.

A typhoon has forced the Philippines to delay COVID-19 vaccinations of millions of people living in the path of the storm. Half of the country's 110 million population has received at least one dose of a COVID-19 vaccine.

Rwanda has confirmed six cases of the Omicron variant of COVID-19, the health ministry said, as it urged people to get vaccinated.

Italy has extended a COVID-19 state of emergency to 31 March and ruled that all visitors from EU countries must take a test before departure, amid concerns over the spread of the Omicron variant.

All three U.S.-authorized COVID-19 vaccines appear to be significantly less protective against the newly-detected Omicron variant of the coronavirus in laboratory testing, but a booster dose probably restores most of the protection, according to a study released on Tuesday.

The study from researchers at Massachusetts General Hospital (MGH), Harvard and MIT, that has not yet been peer-reviewed, tested blood from people who received the Moderna, Johnson & Johnson and Pfizer/BioNTech vaccines against a pseudo-virus engineered to resemble the Omicron variant.

The researchers found "low to absent" antibody neutralization of the variant from the regular regimens of all three vaccines - two shots of the Moderna or Pfizer/BioNTech vaccines or one of J&J's single-dose vaccine.

But the blood from recent recipients of an additional booster dose exhibited potent neutralization of the variant, the study found.

The scientists also suggested that Omicron is more infectious than previous variants of concern - about twice as transmissible as the Delta variant, which may soon be overtaken by Omicron.

The results are in line with other studies recently published.

Pfizer and BioNtech are set to displace AstraZeneca as the main suppliers of COVID-19 vaccines to the global COVAX programme at the start of 2022, a shift that shows the increasing importance of their shot for poorer states.

The expected change comes with headaches for receiving countries that lack sufficient cold storage capacity to handle the Pfizer vaccine, and amid risks of a shortage of syringes needed to administer that shot.

AstraZeneca is currently the most distributed vaccine by COVAX, according to data from Gavi, the vaccine alliance that co-manages the programme with the World Health Organization (WHO).

The programme has so far delivered more than 600 million shots to nearly 150 countries, of which more than 220 million are AstraZeneca's and about 160 million Pfizer's.

But in the first quarter of next year Pfizer is set to take over, according to Gavi and WHO figures on doses assigned by the COVAX programme for future supplies.

By the end of March, another 150 million Pfizer doses are to be distributed by COVAX, a WHO document shows.

A spokesperson for Gavi confirmed that Pfizer is ahead in terms of "allocated" jabs, with about 470 million doses delivered or readied for delivery, against 350 million from AstraZeneca.