Capital punishment in Japan Three inmates in Japan are executed by hanging, marking the first executions in the country in nearly two years. One inmate was the perpetrator of a 2004 mass stabbing in which he killed seven of his relatives.
Lithuania–United States relations The U.S. State Department approves the sale of 341 FGM-148 Javelin anti-tank guided missiles and 30 command launch units to NATO ally Lithuania amid rising tensions with Russia.
COVID-19 pandemic California Governor Gavin Newsom announces that healthcare workers will be required to receive a COVID-19 vaccine booster dose in order to keep their "fully vaccinated" status, becoming the second state to impose such mandate.
New Zealand postpones a phased reopening of the border for quarantine-free travel to the end of February in order to strengthen the country's defence against the spread of the Omicron variant.
Argentina reports 9,336 new cases of COVID-19 in the past 24 hours, the highest daily total in 4 months, thereby bringing the nationwide total of cases to 5.4 million.
The provinces of Buenos Aires, Córdoba, Santa Fe, Río Negro and Santiago del Estero begin implementing the usage of a "sanitary pass" for large events.
Thailand reinstates its mandatory hotel quarantine for all incoming foreign travellers and suspends the "sandbox" program for places other than Phuket after the country reported its first locally transmitted case of the SARS-CoV-2 Omicron variant.
The Philippine Food and Drug Administration reduces the interval of the COVID-19 vaccine booster dose to three months for people who received a two-dose vaccine and two months for people who received a single-dose vaccine in order to reduce the effects of variants.
Israel reports its first confirmed death related to the SARS-CoV-2 Omicron variant in a man in his 60s with pre-existing health conditions who died at the Soroka Medical Center in Beersheba.
The Health ministry recommends that Israelis over the age of 60 years and healthcare workers should receive a fourth dose of the COVID-19 vaccine, becoming the world's first country to administer a fourth dose of the vaccine. The move is welcomed by Prime Minister Naftali Bennett.
The European Commission announces a binding proposal that will make the EU Digital COVID Certificate only valid for travel within the European Union for nine months without a booster dose after a person's primary vaccination schedule in order to standardize different travel requirements in the member states. The new rules will be mandatory for all 27 EU member states beginning on February 1.
The Swedish government announces that several new measures will begin on December 23, including limiting the number of people at private gatherings to 50, requiring the use of a vaccination pass for public events with a capacity of more than 500 people, and recommending work from home where possible, due to an increase in the number of COVID-19 cases.
Prime Minister António Costa announces that nightclubs and bars will be closed and all people will work from home for at least two weeks beginning on December 25 in order to reduce the spread of COVID-19. There will also be capacity restrictions at shops and people will require a negative COVID-19 test in order to enter events.
German Chancellor Olaf Scholz and 16 state premiers agree to tighten the restrictions beginning on December 28, including limiting the number of people in private gatherings to 10 and banning spectators at large-scale musical, sporting and cultural events due to concerns related to the spread of the Omicron variant.
The Standing Committee on Vaccination recommends the shortening of the interval between the second dose and booster dose of the COVID-19 vaccine to three months and urges all citizens over the age of 18 to receive a booster dose of an mRNA-based vaccine after receiving their first two doses in order to reduce the spread of the SARS-CoV-2 Omicron variant.
December 2021 Malaysian floods Heavy floods continue to affect eight Malaysian states for the third day, killing 14 people and partially submerging several towns and villages.
Tigray War The Tigray Defense Forces withdraws all its troops from the Afar and Amhara regions of Ethiopia.
Insurgency in the Maghreb The French Army announces that they have killed Soumana Boura, a leading member of the Islamic State in the Greater Sahara, the previous day. Boura was involved in the killings of six French aid workers and their two Nigerien guides in a mass shooting in August 2020 in Kouré, Niger.
Yemeni Civil War The Saudi-led coalition launches airstrikes on Sanaa International Airport in the Yemeni capital Sanaa. The air raid targeted six sites, including places used for "launching drone attacks", according to a statement from the coalition.