Before the omicron, booster vaccines are reconsidered

Just a week ago, many health experts strongly opposed the Joe Biden government’s campaign to give all adults in America a booster shot of the coronavirus vaccine. The researchers cautioned that there was little scientific evidence to support additional doses for most people.

The omicron variant has changed all that.

Scientists still don’t know for sure if the virus spreads more easily or is less vulnerable to the immune system’s response. But with the appearance of dozens of new mutations, it seems that this variant could manage to circumvent, to a significant degree of importance, the protection of vaccines.

Booster doses clearly raise antibody levels, causing the body’s defenses to strengthen against infection, and could help mitigate any advantages the omicron variant has gained through evolution.

Many experts who opposed booster vaccines now believe that the injection might be the best defense against the new variant. The extra doses could, at the very least, buy vaccine manufacturers time to develop, if necessary, a specific formula for the omicron variant.

“Based on what we know about possible immune evasion, I would rather be wrong in recommending the booster dose,” said Celine Gounder, an infectious disease specialist at Bellevue Hospital Center, who had opposed the Biden administration’s proposal. to provide booster injections to the entire population.

The US government is not waiting for scientific consensus. Officials at the Centers for Disease Control and Prevention, concerned about preliminary reports of omicron, said Monday that all adult Americans should receive booster doses.

The first confirmed case of infection with the omicron variant in the United States was recorded Wednesday in San Francisco, in a person who returned to California from a trip to South Africa on November 22. The person, who had mild symptoms and was said to be improving, had the full vaccination schedule, but had not received a booster dose.

The omicron variant, which was first identified in southern Africa, has been found in at least 20 countries, and the World Health Organization has warned that the risk from the virus is “very high.” After news of the spread of the variant in South Africa broke, some countries have restricted flights to and from southern Africa.

Ómicron has more than 50 genetic mutations, more than thirty of them in the spicule, a protein on its surface. Vaccines train the body’s immune defenses to target and attack those spicules.

Until now, experts like Gounder had argued that although the potency of the infection vaccines seemed to decrease with the delta variant, they still protected most people from serious illness, hospitalizations and death. For the same reason, the booster doses should be recommended only for adults over 65 years of age and those who are in long-term care centers or have a weak immune system, they said.

Gounder and other researchers said that if delta were the only threat, booster doses would not be justified. But the omicron variant may be a more important foe.

“If it is very resistant to antibodies, which seems possible but has not been proven, then additional doses are appropriate,” said John Moore, a virologist at Weill Cornell Medicine in New York.

“I’d like to analyze more data, but it won’t hurt anyone to have additional protection.”

Even before the arrival of the omicron variant, some experts began to reconsider the reinforcement plan for all adults as cases have increased again in recent weeks in the United States.

“It’s affecting things like elective procedures at various hospitals in Massachusetts and elsewhere,” said Camille Kotton, an infectious disease physician at Massachusetts General Hospital and a consultant for the CDC. “We really have to end this.”

“Now, more than ever, is a good time for people who have not yet been vaccinated to get vaccinated or to go get boosters,” he said.

Kotton’s initial doubt was in part a lack of research on the safety of booster vaccines in young adults. Given certain rare heart problems in young men after receiving the second dose of an mRNA vaccine, it was unclear whether the benefits outweighed the risks.

But the data now available has lessened her concerns, she said, so much so that she has urged her college-age children to go for their booster doses.

“Oh yeah, I changed,” he said. “When balancing the risks and benefits, it is a very good idea to opt for a booster dose for people who qualify for it.”

In the long term, more support from the scientific community for the reinforcements may complicate efforts to bring supplies of coronavirus vaccines to poor countries. For months and long before the appearance of the omicron variant, the World Health Organization has said that the clamor for booster doses in rich countries was depriving poorer nations of the first doses they desperately needed.

Despite the WHO designation of omicron as high risk, the organization has not changed its stance on the reinforcements.

“At this time, there is no evidence that I am aware of to suggest that giving booster doses to the entire population will provide greater protection against hospitalization or death to healthy people,” Mike Ryan told a news conference Wednesday, a WHO manager.

He and other scientists have said that the uncontrolled spread of the coronavirus in largely unvaccinated populations, such as those in Africa, could lead to variants such as omicron.

Not all experts support booster shots.

The push for extra doses is based on the idea that antibodies are at the heart of immunity, a false perspective that overlooks the importance of other parts of the immune system in preventing serious illness and death, Paul said. Offit, director of the Center for Vaccine Education at Children’s Hospital of Philadelphia and advisor to the Food and Drug Administration.

He said he would be more concerned if vaccinated people infected with the omicron variant were being hospitalized en masse. But the scant evidence to date suggests that vaccines continue to prevent serious disease, he said.

“That has always been true: it has been true for the first three variants, and it is likely to be true in this case,” he said. “If your goal is protection against mild illness, then we are going to be giving ourselves booster shots until the day we die.”

Even if omicron turns out to be vaccine resistant, an additional injection of the original vaccines may not be the best solution, Offit said: not vaccinated ”.

However, waiting may not be an option.

If laboratory tests indicate that omicron dodges vaccines, manufacturers say they are prepared to adapt new versions. That process will take at least a few months, and booster shots of current vaccines may be needed to help keep the variant at bay until then.

Even if the antibodies stimulated by those vaccines aren’t as effective at defending themselves against omicron as they were against previous variants, simply increasing the amount could compensate, Gounder said.

“You can cancel part of that lower affinity by having a higher number,” he said.

If necessary, multiple booster doses – first with current vaccines and then with omicron-specific versions – would have to be exquisitely timed, because boosting immunity too often can backfire, Moore said. Some immune cells may stop responding to vaccines.

“This is where everything gets complicated; certainly no one should get carried away by dogma, “he said. “We are reacting in an environment of little information where the consequences are potentially very serious.”

Apoorva Mandavilli is a reporter for the Times and focuses on science and global health. In 2019 he won the Victor Cohn Award for Excellence in Medical Science Reporting.@apoorva_nyc


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