US approves new round of Covid boosters

Alluding to the ongoing risk the coronavirus poses to millions of Americans, the Centers for Disease Control and Prevention on Wednesday recommended that adults ages 65 and older and those with compromised immune systems get another dose of the newly formulated booster, which was released last fall was introduced.

The approval followed a day-long discussion by the CDC’s expert advisers. The Food and Drug Administration approved the booster plan Tuesday, and the CDC’s recommendation was the final administrative step. Eligible Americans can receive booster doses immediately.

Federal health authorities are also issuing and revoking the original vaccine formulas developed by Pfizer-BioNTech and Moderna in the United States. And instead of requiring an initial series of two shots, unvaccinated people now only need a single dose of the reformulated or “bivalent” Covid vaccine to be considered vaccinated.

Until now, federal officials had required two doses of the older vaccine before recipients could receive the bivalent boosters, a process some experts found confusing.

Limited data on the reformulated vaccines indicate that the shots provide additional protection against serious illness and death from Covid in older adults, although protection wears off quickly in the weeks following vaccination.

According to the Census Bureau, there are about 53 million adults age 65 and older in the United States, which is about 16 percent of the population. And seven million Americans have compromised immune systems due to an illness or drug.

Around 250 people are still dying every day in the United States from Covid-related causes, the vast majority of whom are over the age of 70 or have compromised immune systems. The median age of hospitalized patients is 75, according to the CDC. So far, however, only about 43 percent of adults age 65 and older have received a bivalent booster shot.

More about the corona pandemic

By this point, most Americans have built up some immunity to the virus, whether through previous infections, vaccinations, or both. The new guidelines recognize this, but allow those who are still at high risk from the virus to protect themselves, and it’s free.

“The unity policy was simple but not optimal,” said Dr. Jeremy Faust, an emergency medicine physician and public health policy expert at Brigham and Women’s Hospital in Boston. “The new regime recognizes that there is now an exceptional spectrum of Covid risks, from mild to severe, depending on who you are.”

People who are severely immunocompromised, such as B. Recipients of organ transplants should perhaps opt for booster vaccinations every six months or even more frequently, said Dr. Fist.

The new guidelines come weeks after Britain and Canada recommended additional vaccinations for older adults and the immunocompromised. (Britain recommended admissions for those aged 75 and over, and Canada only for those aged 80 and over.)

Adults age 65 and older can choose to have another dose of the bivalent vaccine at least four months after their first vaccination, according to the CDC. Those with a compromised immune system can do this two months after their previous bivalent dose and, in consultation with their doctor, may elect to have additional doses.

At the CDC advisors’ meeting on Wednesday, Dr. Camille Kotton, a physician at Massachusetts General Hospital, notes that the new recommendations do not include immunocompromised children ages 6 months to 4 years. This leaves these medically frail children — including organ transplant recipients — vulnerable to the virus, she said.

“As a mother and as a doctor, it seems like we’re leaving her so vulnerable,” she said in an interview.

For most Americans, the FDA plans to encourage annual fall Covid shots, similar to flu shots. The exact composition of the shot will be decided by health authorities in June based on the version of the virus circulating at the time.

The bivalent vaccine targets the original variant of the coronavirus as well as the variants BA.4 and BA.5 that were dominant last summer. But BA.4 and BA.5 were quickly supplanted by newer versions.

The latest Omicron subvariant, XBB.1.5, now accounts for about 78 percent of cases in the United States, and another version, XBB.1.6, accounts for about 7 percent. So far, the reformulated vaccines appear to prevent serious illness and hospitalization after infection with these variants.

Federal health officials are also making changes to procedure for those who receive the first shots.

Unvaccinated individuals will receive a single dose of the bivalent vaccine rather than multiple doses of the original monovalent vaccine. The rationale is that most unvaccinated Americans now probably have some level of immunity from a previous infection and may not need two doses to start, the FDA said.

Some experts sharply criticized the advice. A wealth of data suggests the vaccines are best protective when given in two doses and followed by one or more boosters to strengthen the protective shield, said John Moore, a virologist at Weill Cornell Medical College.

“The FDA has consistently overinterpreted the performance of the bivalent formulation when administered as a booster vaccine,” said Dr. Moore. “Now it seems to have gone beyond science and decided that as a first dose it has some sort of magical power.”

It may be reasonable to assume that almost all unvaccinated adults have been infected at least once and can get by with just a single dose, said Deepta Bhattacharya, an immunologist at the University of Arizona.

“I think the FDA is just trying to simplify given the reality on the ground,” he said. But “immunologically you would want to take two shots if it’s your first exposure.”

The agency could recommend two doses of a bivalent vaccine instead, saying those who know of a previous infection can skip the second dose, Dr. Bhattacharya. But, he added, “in reality I doubt that a clause like this would make much practical difference.”

The FDA said it “carefully reviewed the available epidemiological evidence, scientific publications, and data provided by sponsors that suggest that a single dose of bivalent vaccine given to individuals previously infected with Covid-19 elicits an immune response that equivalent to two doses or better is the original vaccine.”

“The agency believes this approach will help encourage future immunizations, particularly among those who have not previously made a choice to vaccinate,” the FDA said in its statement.