The nurses of California are afraid. It’s Christmas Eve, and they aren’t home with their families. They are working, always working, completely gowned up — and worn down. They’re frightened by what people are doing, or not doing, during a coronavirus pandemic that has already killed more than 320,000 nationwide and shows no signs of slowing down. They’re even more terrified of what’s next. “Every day, I look into the eyes of someone who is struggling to breathe,” said nurse Jenny Carrillo, her voice breaking. A charge nurse at Providence Holy Cross Medical Center in Los Angeles’ San Fernando Valley, Carrillo is haunted by the daily counts of COVID-19 patients. Dark shadows circle her eyes.

With rich countries snapping up supplies of COVID-19 vaccines, some parts of the world may have to rely on Chinese-developed shots to try to conquer the outbreak. The question: Will they work? There is no outward reason to believe they won’t, but China has a history of vaccine scandals, and its drugmakers have revealed little about their final human trials and the more than 1 million emergency-use inoculations they say have been carried out inside the country already. Wealthy nations have reserved about 9 billion of the 12 billion mostly Western-developed shots expected to be produced next year, while COVAX, a global effort to ensure equal access to COVID-19 vaccines, has fallen short of i ts promised capacity of 2 billion doses.

The United States will require airline passengers from Britain to get a negative COVID-19 test before their flight. The U.S. is the latest country to announce new travel restrictions because of a new variant of the coronavirus that is spreading in Britain. The Centers for Disease Control and Prevention says airline passengers from the United Kingdom will have to get negative COVID-19 tests within three days of their trip and provide the results to the airline. The agency says the order will be signed Friday and go into effect on Monday. The CDC says because of travel restrictions in place since March, air travel to the U.S. from the U.K. has been cut by 90%.

HaGaon HaRav Yitzchak Zilberstein, Rav of Ramat Elchanan and a member of the Moetzes Gedolei HaTorah, publicized a p’sak din halacha on Wednesday on being vaccinated against the coronavirus. HaRav Zilberstein wrote the p’sak after holding a meeting with Prof. Ron Balicer, a member of the Health Ministry’s advisory team on COVID-19, and other medical experts, on the effectiveness and safety of the vaccine. HaRav Zilberstein wrote that since we currently we don’t have a Beis Din of Rabbanim who are oisek in refuah, the Aruch HaShulchan says that during these times we must rely on doctors who have been approved by the government to practice medicine.

Kale Wuthrich watched doctors surround his son in the emergency room, giving him fluids though IV tubes, running a battery of tests and trying to stabilize him. He was enveloped by the confusion and fear that had been building since his 12-year-old suddenly fell ill weeks after a mild bout with the coronavirus. “He was very close at that point to not making it, and basically they told me to sit in the corner and pray,” Wuthrich said. “And that’s what I did.” Shortly after Thanksgiving, the boy from a secluded valley in Idaho became one of hundreds of children in the U.S. who have been diagnosed with a rare, extreme immune response to COVID-19 called multisystem inflammatory syndrome in children.

Russia’s Health Ministry agreed Wednesday to cut the size of a study of a domestically developed coronavirus vaccine and to stop the enrollment of volunteers. The decision comes a week after developers said enrollment of study volunteers has slowed since Russia began giving out the Sputnik V vaccine while the late-stage study was still continuing. They also cited ethical concerns about giving a dummy shot to some of the volunteers. The study size was cut to about 31,000 from 40,000 participants. Alexander Gintsburg, head of the Gamaleya Center, the state-run medical research institute that developed Sputnik V, said that many of those who received dummy shots had figured it out and gotten vaccinated.

Germany reported a record level of coronavirus deaths as it entered a harder lockdown Wednesday, closing shops and schools to try to bring down stubbornly high new daily infections. The country recorded 179.8 virus infections per 100,000 residents over the last seven days, a new high and significantly more than the 149 per 100,000 reported a week ago by the Robert Koch Institute, the country’s disease control center. It also blew past its previous daily death toll, with Germany’s 16 states reporting that 952 more people had died of the virus, the institute said. That was far greater than the previous daily record set Friday of 598 deaths, although it included two days of figures from the hard-hit eastern state of Saxony, which did not report Tuesday.

Another new variant of the coronavirus appears to have emerged in Nigeria, Africa’s top public health official said Thursday, but he added that further investigation was needed. The discovery could add to new alarm in the pandemic after similar variants were announced in Britain and South Africa, leading to the swift return of international travel restrictions and other measures just as the world enters a major holiday season. “It’s a separate lineage from the UK and South Africa,” the head of the Africa Centers for Disease Control and Prevention, John Nkengasong, told reporters. He said the Nigeria CDC and the African Center of Excellence for Genomics of Infectious Diseases in that country — Africa’s most populous — will be analyzing more samples.

Canada’s health regulator authorized a second COVID-19 vaccine Wednesday and Prime Minister Justin Trudeau said he will extend the suspension of flights from the United Kingdom because of a new variant there, calling the situation “very serious.” Health Canada said the vaccine from U.S. biotech firm Moderna is safe for use in the country and Moderna said it anticipates starting shipments to Canada within 48 hours. It follows the Dec. 9 approval of the Pfizer-BioNTech vaccine. Up to 168,000 doses of the Moderna shot are set to arrive by the end of December, and 2 million by the end of March. Canada is to get 40 million doses of Moderna’s vaccine in 2021, enough to vaccinate 20 million people, or about two-thirds of the Canadian adult population.

Two new studies give encouraging evidence that having COVID-19 may offer some protection against future infections. Researchers found that people who made antibodies to the coronavirus were much less likely to test positive again for up to six months and maybe longer. The results bode well for vaccines, which provoke the immune system to make antibodies — substances that attach to a virus and help it be eliminated. Researchers found that people with antibodies from natural infections were “at much lower risk … on the order of the same kind of protection you’d get from an effective vaccine,” of getting the virus again, said Dr. Ned Sharpless, director of the U.S. National Cancer Institute. “It’s very, very rare” to get reinfected, he said.