FDA advisers to determine if Omicron-specific vaccines are needed


The United States is preparing for the possible need to update its vaccines against Covid-19.

The U.S. Food and Drug Administration’s Independent Advisory Committee on Vaccines and Related Biologicals is due to meet on Tuesday to discuss whether the composition of Covid-19 vaccines should be changed to target a specific strain of coronavirus and, if so, which strain should be selected.

This means that the Covid-19 vaccines people will receive in the future could be somewhat or completely different formulations from those being given now. Current vaccines are based on the coronavirus that emerged in late 2019, but experts will discuss on Tuesday whether vaccines should also target the Omicron variant.

At their meeting, VRBPAC members will vote on the question: “Does the committee recommend the inclusion of a SARS-CoV-2 Omicron component for COVID-19 booster vaccines in the United States?”

It is a moment of transition for the approach to coronavirus vaccines. There is growing anticipation that vaccinations may be needed every year – in the same way that seasonal flu shots are given every year.

“It’s expected that we’ll need a fall reminder and what that framework would look like and if a vaccine is needed because of a different variant,” Lori Tremmel Freeman, chief executive of CNN, told CNN. the National Association of County and City Health Officials. .

“It gets difficult, because is it really a booster if it’s not the same formulation? And should we talk about it that way or is it just a new vaccination? Freeman added. “We don’t discuss the fact that we’ve had flu shot boosters over the years. This is part of the flu vaccination process each year. This transition is therefore important.

In May, a trio of senior FDA officials wrote in the medical journal JAMA that the United States may need to update its Covid-19 vaccines every year and “a new normal” could include a Covid-19 vaccine. annually along with a seasonal influenza vaccine.

“By the summer, decisions will need to be made for the 2022-2023 season regarding who should be eligible for vaccination with additional boosters and regarding the composition of the vaccine,” wrote Dr. Peter Marks, director of the Center for FDA Biologics Evaluation and Research; Senior Deputy Commissioner Dr. Janet Woodcock; and FDA Commissioner Dr. Robert Califf.

“Giving additional doses of COVID-19 vaccine to appropriate people this fall at the time of the usual influenza vaccination campaign has the potential to protect susceptible people from hospitalization and death, and will therefore be a subject to be debated. review by the FDA,” they wrote.

FDA vaccine advisers previously met in April to discuss how the composition of Covid-19 vaccines could change to target all new and emerging coronavirus variants. The committee agreed that there needs to be a framework to determine how and when such changes take place.

The FDA’s Marks called this year “transitional” in how we view the evolution of the Covid-19 vaccine schedule.

“The assumption now is that it’s going to look a bit like the flu. In this 2022-23 season, instead of just getting your flu shot, you’ll also get your booster for Covid-19. And we’ll see how that is happening,” Marks told Bloomberg in an opinion piece earlier this month.

“If the people who get this boost do well and we seem to have avoided another big wave from October to March-April next year, we’ll have people used to it,” he said. .

People aged 5 and over are already eligible for booster doses, and some immunocompromised people and adults 50 and over are eligible for additional doses of the Covid-19 vaccine.

“We need to start thinking about vaccines that we can adjust the strains of once a year and make it a model of the flu rather than saying, OK, every five or four months you’ll get another booster,” Marks said. at Bloomberg. “The idea here is that next year we have a campaign, and we don’t have to follow it with another booster campaign. Ultimately, next-generation vaccines would ideally help hold us back for this full year.”

Currently, the original versions of the Pfizer/BioNTech, Moderna and Johnson & Johnson coronavirus vaccines are in use in the United States – but the vaccine makers have been working on updated versions of their vaccines.

Moderna has developed a bivalent Covid-19 vaccine booster, named mRNA-1273.214, which the company announced this month has been shown to elicit “potent” immune responses against Omicron BA subvariants. 4 and BA.5. This bivalent booster vaccine candidate contains components of Moderna’s original Covid-19 vaccine and a vaccine that targets the Omicron variant. J

On Saturday, Pfizer and BioNTech said their two Covid-19 vaccine boosters targeting Omicron showed a significantly higher immune response than its current Covid-19 vaccine, and preliminary lab studies suggest the vaccines could neutralize Omicron BAs. 4 and BA.5.

Another vaccine maker, Novavax, has received VRBPAC support for emergency use authorization in the United States, but has not yet been cleared by the FDA. Novavax scientists have also developed updated variant-specific versions of their Covid-19 vaccine as well as a combined Covid-19 and influenza vaccine.

Public health experts fear there will be slow uptake of any modified Covid-19 vaccine in the future.

“Our booster usage rate isn’t that high so far, and so another booster isn’t necessarily going to cause people to burn out and get the boosters they’ve already missed,” said Freeman.

About two-thirds of the U.S. population — 67% — are fully immunized against Covid-19 with at least their initial round of vaccines, but less than a third — 32% — have received their boosters, CDC data shows, like Friday.

Childhood vaccination rates still lag far behind other age groups – only 30% of children aged 5-11 and 60% of those aged 12-17 are fully vaccinated, compared to nearly 77% of adults . National data on vaccination rates for children under 5, who became eligible this month, likely won’t be available for a few weeks.

The CDC still considers receiving two doses of the Pfizer/BioNTech or Moderna vaccines or a single dose of the Johnson & Johnson vaccine to be fully vaccinated. All additional doses are called ‘booster’ and completion of all recommended boosters of the vaccine is considered ‘up to date’.

But that language and messaging around completing booster doses – and seeing them as being up to date instead of part of a full vaccination – ‘doesn’t work,’ specialist scientist Dr Peter Hotez said. in vaccines and dean of the National School of Tropical Medicine. at Baylor College of Medicine, CNN told CNN. This is evident in the slow absorption of additional doses.

“Since early January 2021, I’ve said it’s always been a three-dose vaccine,” he said.

Now people who have not yet completed their booster doses become more vulnerable to infections, hospitalizations and deaths from Covid-19.

“There are dire consequences because we are starting to see not just breakthrough hospitalizations, but even breakthrough deaths in people receiving only two doses of vaccine and not receiving the booster – especially those over the age of 65 – c It is therefore more than a theoretical discussion. Lives are being lost to messaging,” Hotez said.

At the moment, vaccine-induced protection against Covid-19 doesn’t seem to last as long as vaccine experts hope, but it’s unclear why. The waning protection could be due to the vaccines themselves or the emergence of vaccine-evading coronavirus variants.

Hotez said he thinks the White House should convene a panel of vaccine experts — outside of the FDA’s VRBPAC — in a special meeting to determine whether the Covid-19 vaccine technology has a weakness in vaccines. sustainability and what this means for future vaccine strategies. .

“Two things are happening at the same time. There could be waning immunity,” Hotez said, but at the same time variants like Delta and Omicron came to the scene.

“If all we had to worry about was Delta, would we have a problem? Or would things have held up? And so I don’t know the answer to that,” Hotez said. “That’s why you want to summon the experts.”


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