Scientific advisers to the Centers for Disease Control and Prevention will take up a thorny challenge on Thursday: Who qualifies for the new Pfizer-BioNTech coronavirus booster and why?
On Wednesday evening, the Food and Drug Administration authorized booster shots of the vaccine for people over 65 who received their second at least six months earlier. The agency also approved boosters for adult Pfizer-BioNTech recipients who are at high risk of severe Covid-19, or who are at risk of serious complications because of exposure to the virus in their jobs.
Roughly 22 million Americans are at least six months past their second Pfizer dose, according to the C.D.C. About half are 65 or older.
But who exactly risks becoming severely ill? What does it mean to be exposed on the job? Do teachers count as exposed, or just frontline health care workers? And what about Americans who got the Moderna and Johnson & Johnson shots?
Those are questions scientists on the C.D.C. Advisory Committee on Immunization Practices have been debating, and their decisions will shape the federal government’s guidance.
In its deliberations on Wednesday, the C.D.C.’s advisory committee zeroed in on unanswered questions.
A third dose undoubtedly amps up antibody levels, the experts concluded. But it’s unclear so far how long that increase lasts, whether it translates to meaningful extra protection against severe disease, and whether it can significantly decrease transmission of the virus.
Scientists on the committee also noted the paucity of safety data, especially among younger people. And several advisers said they believed the goal of the boosters should be to prevent severe illness, hospitalization and death, rather than stave off infection.
“I don’t think there’s any hope that vaccines such as the ones we have will prevent infection after the first, maybe, couple weeks that you have those extraordinary immediate responses,” said Dr. Sarah Long, a pediatric infectious disease expert at Drexel University College of Medicine in Philadelphia.
The advisers also wrestled with the practicalities of endorsing a booster shot of Pfizer’s vaccine, but not of Moderna or Johnson & Johnson’s. Recipients of those vaccines may hear that boosters are necessary — but they can’t have them yet.
“That’s a big public health panic that we would like to avoid,” Dr. Long said.
Moderna has applied for F.D.A. authorization of booster shots, but at half the dosage given in the first two.
Mixing first shots of the Moderna vaccine with a Pfizer booster — or vice versa — is untested ground, and federal agencies are always reluctant to make moves that the evidence doesn’t explicitly support.
Some global health experts have criticized the Biden administration for pushing booster shots when much of the world has yet to receive a first dose. But on Wednesday, Jen Psaki, the White House press secretary, argued that was a “false choice.”
On Wednesday morning, President Biden said the United States would buy 500 million more doses of the Pfizer-BioNTech vaccine to donate worldwide, doubling up on a purchase in July.
“We’re now donating three shots globally for every one shot we put in the arm of an American, and our view continues to be that we can do both,” Ms. Psaki said. “Our view also continues to be that frankly the rest of the world needs to step up and do more.”
Sharon LaFraniere and Noah Weiland contributed reporting from Washington. Daniel E. Slotnik contributed reporting from New York.
Alaska, once a leader in vaccinating its citizens, is now in the throes of its worst coronavirus surge of the pandemic, as the Delta variant rips through the state, swamping hospitals with patients.
As of Tuesday, the state was averaging 117 new cases a day for every 100,000 people, more than any other in the nation, according to recent data trends collected by The New York Times. That figure has shot up by 42 percent in the last two weeks, and by more than twentyfold since early July.
On Wednesday, the state said it had activated “crisis standards of care,” giving hospitals legal protections for triage decisions that force them to give some patients substandard care. The state also announced an $87 million contract to bring in hundreds of temporary health care workers.
Gov. Mike Dunleavy, a Republican, said that while hospitals were strained, he did not see a need to implement restrictions aimed at curbing transmission. Still, he encouraged people who had not yet received a vaccination to seriously consider it.
“We have the tools available to us for individuals to be able to take care of themselves,” Mr. Dunleavy said. While the state led the nation in vaccinations early in the year, it has been lagging in recent months, with under half of its population fully vaccinated, compared with 55 percent nationally, according to federal data.
Jared Kosin, the head of the Alaska State Hospital and Nursing Home Association, called the surge “crippling” in an interview on Tuesday. He added that hospitals were full, and health care workers were emotionally depleted. Patients are being kept waiting for care in their cars outside overwhelmed emergency rooms.
There is growing anxiety in outlying communities that depend on transferring seriously ill patients to hospitals in Anchorage, Mr. Kosin said. Transfers are getting harder to arrange and are often delayed, he said.
“We are all wondering where this goes, and whether that transfer will be available, even tomorrow,” Mr. Kosin said.
Critically ill people in rural areas, where many Alaska Natives reside, often have to be taken by plane to a hospital that can provide the treatment they need, said Dr. Philippe Amstislavski, an associate professor of public health at the University of Alaska Anchorage.
“Unlike in the lower 48, you don’t have that ability to move people quickly, because of the distances and remoteness,” said Dr. Amstislavski, who was formerly the public health manager for the Interior Region of Alaska, focusing on rural and predominantly Alaska Native communities.
Mr. Kosin said that if hospitalizations rise much further, hospitals and clinics around the state could be forced to apply crisis standards of care and more extreme triage decisions. “That is the worst-case scenario we could be heading to,” he said.
Alaska Natives, who have historically suffered from health disparities in the state, are disproportionately struggling during the latest virus wave, Dr. Amstislavski said.
Dr. Anne Zink, Alaska’s chief medical officer, said several factors may be contributing to the surge, including summer tourists bringing in and spreading the virus.
“We’re hoping that as the snow falls and we have less people visiting, those numbers will settle down,” Dr. Zink said in an interview Tuesday night.
On the other hand, she noted that cooling weather drives residents indoors, where the virus spreads more readily.
The state’s Canadian neighbors to the east, Yukon and British Columbia, have not suffered such severe outbreaks, Dr. Amstislavski said, possibly because of that country’s stricter travel restrictions and less strained health care system.
Australia’s second most populous state announced that some residents stranded in surrounding regions because of the pandemic would be able to travel back home starting Sept. 30.
On Thursday, the state premier, Daniel Andrews, said that people who had been stuck in New South Wales for “a lengthy period of time” could return to Victoria, if they were fully vaccinated and tested negative for the coronavirus. They must quarantine for 14 days.
“We have on numerous occasions sent our apologies to them and made it clear we understand just how challenging it is and we wish things were different,” he said.
Australia has imposed some of the harshest restrictions in the world to help contain the spread of the virus, with individual states employing lockdowns that have prevented people from returning to their cities.
The daily average of new cases has dropped 13 percent in the past two weeks in Australia, which has lived through several lockdowns since the start of the pandemic. While its vaccination kickoff had a slow start, the nation has to date fully vaccinated 39 percent of its population. Recently the country began vaccinating children as young as 12.
While travel restrictions have eased for many Australians, and the tourism ministry has even announced a possible reopening of its borders by Christmas, the country is still facing setbacks with new infections breaking out.
A makeup artist working on an Australian reality television program tested positive for the coronavirus earlier this week, sending over 130,000 Australians into yet another lockdown, according to Chris Cherry, the mayor of Tweed Shire, part of the area in northern New South Wales that has been placed under restrictions for seven days.
According to ABC News, the 31-year-old woman visited various businesses like restaurants and cafes without checking in via QR code. The police have charged her with breaching several public health regulations, including her work travel exemption guidelines.
Michael Lyon, the mayor of neighboring Byron Shire, shared his frustration over going back into lockdown in a Facebook post on Wednesday.
“It is so devastating to be in lockdown again and it is clear the ‘honour’ system relied on by the state government is deeply flawed,” he wrote. “Perhaps our calls for a tightening of restrictions will now finally be heeded.”