This story was updated on June 16, 2023.
June 15, 2023 – The FDA today announced that the following COVID-19 vaccines should goal the XBB variants of the SARS-CoV-2 virus currently circulating within the United States and advised manufacturers to start planning vaccinations now for the autumn.
“The FDA will continue to monitor the safety and effectiveness of COVID-19 vaccines as well as the evolution of the SARS-CoV-2 virus,” the agency said in a press release.
On Twitter, the FDA said: “The agency expects the data and documentation to be submitted in a timely manner to support FDA's actions on updated COVID-19 vaccines so that vaccines that meet our expectations for safety, effectiveness, and quality will be available this fall.”
The move got here a day after the FDA's Vaccines and Related Biological Products Advisory Committee voted 21-0 to recommend using the strain in the following generation of vaccines.
In the Briefing document At the briefing, FDA staff said available evidence suggests a monovalent (single-strain) vaccine of the XBB lineage is “warranted” for the 2023-2024 vaccination campaign and would replace the present bivalent vaccine that targets the unique version of the virus and two strains of the omicron variant.
FDA staff also noted that such a reorientation can be consistent with the World Health Organization's strategy, which focuses on combating XBB subvariants. European regulators have also done so.
The FDA isn’t required to follow the panel's recommendations, but it surely often does and can almost definitely achieve this on this case. Vaccine manufacturers need the FDA's suggestion to start producing vaccines in the autumn.
A recent shot every yr?
The FDA has simply asked its panel of experts to vote on the composition of future vaccines and the strains to be included.
However, in the course of the meeting, panelists also raised other issues, including concerns about efforts to tie COVID vaccinations to the annual flu shot model.
Paul Offit, MD, director of the Vaccine Education Center at Children's Hospital of Philadelphia, argued for more attention to be paid to the T cell response after vaccination, even in light of the already known waning of antibody protection.
In a current Substack articleOffit called T cells the “unsung heroes” of the pandemic. Their development after infection or vaccination takes longer than that of the antibodies that first attack the virus, but immune memory cells, called B and T cells, “are long-lived” and their “protection against severe disease often lasts for years and sometimes decades.”
Offit expressed concerns about using a blanket approach to future COVID vaccination recommendations, as is currently done for flu vaccines. The CDC recommends flu vaccinations for everybody aged 6 months and over, with rare exceptions.
“We must continue to define who these high-risk groups are and not make a recommendation for everyone every season,” he said.
Offit cited his own experience for instance. Although he had been vaccinated against the early Wuhan strain of the virus, he was still infected, almost definitely with a variant that emerged later.
“It was a carried-over virus. That's why I had a mild infection, but not a severe one, because I probably had T cells that prevented this severe infection, which can last for years,” Offit said.
Pfizer And Modern, The two firms that produce mRNA-based COVID vaccines are working on experimental products designed to guard against each influenza and SARS-COv-2 with a single injection. Novavax, maker of a more traditional protein-based COVID vaccine, does the identical thing.
The idea behind these combination products is to make it easier for people to guard themselves against each viruses while also providing firms with some marketing advantages.
However, without addressing these pharmaceutical firms' plans for future combination flu and COVID vaccines, FDA panel members on Thursday objected to accepting routine annual vaccinations against SARS-CoV-2 variants.
Among the panelists who expressed concerns was Henry H. Bernstein, DO, a former member of the CDC's Advisory Committee on Immunization Practices.
Bernstein questioned the approach of calling these formulas “2023-2024 formulas,” as this approach creates the impression that annual vaccinations are required, just like the flu.
“It is not yet clear to me whether this is a seasonal virus,” said Bernstein, who can also be a professor of pediatrics on the Zucker School of Medicine at Hofstra/Northwell in New York.
In response to Bernstein's argument, Dr. Arnold Monto, the present FDA panel chairman, suggested that such a pattern could emerge, but acknowledged that it was too early to say needless to say.
Monto is a professor emeritus on the University of Michigan and his profession has included pandemic planning and emergency response to viral outbreaks, including the Hong Kong flu pandemic of 1968, avian influenza, and the unique SARS pandemic.
“I think it's premature to say this virus won't become seasonal,” Monto said of SARS-CoV-2. “I agree. We're not there yet, but maybe we are.”
At the top of the meeting, Monto summarized the important thing points of the meeting, noting that there was general consensus that the XBB.1.5 subvariant can be probably the most suitable for future COVID vaccinations.
He also identified that Novavax, the maker of the more traditional protein-based vaccine, together with Pfizer and Moderna, have already focused on this subvariant, which might enable rapid development of updated COVID vaccines.
“The fact that most manufacturers are willing to work on an XBB 1.5 [vaccine] is an additional reason to select this strain or variant given the immunological data,” Monto said.
Peter Marks, MD, PhD, director of the FDA's Center for Biologics Evaluation and Research, said vaccine manufacturing requirements change annually.
“In practice, there will only be one update per year unless we make a heroic attempt to deal with a strain that emerges that is so fundamentally different that we have to mobilize enormous resources to respond to that strain change,” he said.
Marks questioned panelists' concerns about equating flu and COVID vaccination practices. The FDA staff's intention was to assist the general public understand the necessity for follow-up vaccination, he said.
“I really have trouble understanding why this committee has to get upset about something that resembles the flu. People understand an annual flu shot,” Marks said.
And it's not certain when the XBB subvariant shall be followed by one other major COVID virus change, but it surely's likely that it should occur – and shortly, Marks said.
“It looks like there will likely be further deviations by next fall,” he said.
Informing the general public
Marks also stressed that the advantages of vaccination must be higher communicated to people within the United States.
CDC data estimates that 70% of the U.S. population accomplished the primary series of initial monovalent vaccinations, while only 17% subsequently received bivalent vaccinations. There is even a decline amongst those over 65. CDC estimates that 94% of this group accomplished their primary vaccination series, but only 43% received the bivalent booster dose.
“We have to do better because we failed today to make it clear to the American public what is going on here,” Marks said.
Researchers are also still trying to find out the most effective time to provide additional COVID vaccinations. Finding the “sweet spot” where people can maximize additional protection is difficult because the most effective protection involves individuals who occur to get vaccinated just before virus spread begins to extend, the CDC's Ruth Link-Gelles, PhD, MPH, told the panel during a presentation.
“You'll get the most additional benefit if it's been a long time since your last vaccination,” she said. “But of course, if you leave it too long since your last vaccination, your protection will be very low and you'll be at risk of getting seriously ill.”
Like FDA's Marks, Link-Gelles stressed that more people must be convinced to get follow-up vaccinations.
“Most Americans have not even received the bivalent dose at this point, and so it has been a year or more since their monovalent dose, leaving them with relatively little protection,” she said.