FDA adviser recommends updating coronavirus vaccine targeting XBB

A unanimous vote by the FDA’s independent advisory panel marks the emergence of a global consensus that vaccines should be relaunched without the original strain early in the pandemic.

The currently available version of the vaccine is bivalent, meaning it targets both the original strain and the more recent BA.4 and BA.5 micron variants. But in the four years since the coronavirus began spreading in humans, new ways to circumvent pre-existing immunity have continued to evolve.

The newly chosen target XBB is recombinant virus — A mashup of two descendants of the BA.2 Micron variant. Several flavors of his XBB are currently circulating in the United States, but the Commission and the FDA appear to support the use of his XBB. XBB.1.5highly transmissible Virus version on which Vaccine makers are already conducting important trials.

The XBB spin-offs are so similar to each other that even if they don’t match exactly, it’s hoped that new shots based on one version will provide broad mutual protection against this fall’s prevalent virus. increase.

“Clearly, the data suggests that the older variant is no longer in circulation. It’s XBB. Ah yes. [a change] It makes sense,” said Adam C. Berger, director of the Division of Clinical and Medical Research Policy at the National Institutes of Health’s Office of Science Policy.

The leaders of vaccine companies Moderna, Pfizer and Novavax, which provide immunizations in the United States, released data from animal studies and some limited human studies on a variety of updates. candidates. The potential timeline for distributing the vaccine will depend on which strain the FDA chooses, allowing companies to deliver the XBB.1.5 vaccine sooner than other options.

Renewing the vaccine this year was an easy decision for the committee members. However, some debate whether the scientific understanding of the virus is strong enough to predict that the vaccine will be updated every year in the same way that the flu vaccine is. Virus evolution is inherently unpredictable, and seasonal patterns of this virus are still emerging.

Calling this the 2023-2024 coronavirus vaccine suggests that “this is once a year, and I personally don’t know if this virus exists. Not necessarily seasonal.” It’s not a thing,” said Henry Bernstein, professor of pediatrics at Zucker University. Hofstra/Northwell School of Medicine, NY.

Peter Marks, director of the Center for Biologics Evaluation and Research, said he understands these uncertainties and how companies can manufacture sufficient doses so that public health officials can clearly communicate when people need to be vaccinated. He said it must be balanced against the need to plan to do so. at the FDA.

“While we certainly agree that Covid-19 is not the flu, from a public health perspective, it’s not the same as manufacturing and deploying tens of millions of vaccines. And you have to get it into people’s hands … that’s going to be reduced to a similar type of campaign,” Marks said.

A major concern may prove to be vaccine uptake.that’s all 1 in 5 adults Patients received bivalent boosters, according to Centers for Disease Control and Prevention data.

This worries public health experts. Because while immunity from vaccination and infectious diseases continues to protect most people from serious illness and death, over time the defenses obviously weaken. Data presented at the conference showed a significant decrease in protection against hospitalization 4-6 months after bivalent booster immunization. Older people are the most vulnerable.

“I think we have one chance to have a vaccine this fall, unless a resistant virus develops exceptionally,” Marks said.

Scientists are working to develop a series of next-generation vaccines with even more potential. variant prooflasts longer or can block the transmission of disease. But the most realistic short-term option is to keep track of the virus and update vaccines as it evolves. Several members said that uncertain tracking would not be satisfactory if necessary.

“We have to be prepared for this to be an ongoing process,” said Jerry Weir, director of the Viral Products Division of the FDA’s Center for Biologics Evaluation and Research.