Experts on June 15 recommended updating the COVID-19 vaccines due to the current slate performing worse against the XBB variant and its sublineages.
“We need a better vaccine,” Dr. Eric Rubin, a professor of medicine at Harvard Medical School and one of the advisers, said.
The FDA cleared, and the U.S. Centers for Disease Control and Prevention (CDC) recommended, in the fall of 2022 bivalent vaccines from Moderna and Pfizer that include components of the Wuhan variant and the BA.4/BA.5 subvariants of the Omicron strain with the hope that the updated shots would provide better protection.
XBB, another Omicron subvariant, became dominant in the United States in January.
The updated vaccines will, for the first time ever, not contain a component of the Wuhan variant. Officials say that’s because of signs of immune imprinting, or repeated exposure to the variant, that impedes the immune response to newer strains.
“You won’t be competing with something that people have already seen two, three, four times,” Jerry Weir, an FDA scientist, said.
Dr. Robert Malone, a vaccine expert who is not on the panel, told The Epoch Times that changing the composition of the vaccines is “playing around at the margins.”
“They’re refusing to address the real problem,” he said, which is that the spike protein in the vaccine “is toxic.”
Regulators expect the new vaccines to be available in or near September.
A change “would make this much easier for the companies to deliver and protect people around the world,” said Dr. Steve Pergram, a panel member who is a professor at Fred Hutchinson Cancer Center.
Representatives from Moderna, Pfizer, and Novavax offered animal data that indicates vaccines targeting just XBB trigger higher levels of neutralizing antibodies when compared to the currently available shots.
Moderna also presented clinical trial data that compared adults vaccinated with a monovalent XBB vaccine to people who received a bivalent BA.4/BA.5 plus XBB shot. The monovalent vaccine produced more antibodies.
No trial data with unvaccinated comparators were presented and no data for children were presented.
When Dr. Paul Offit, a panel member, asked the FDA whether such data would be made available before the new vaccines were rolled out, officials refused to say.
If the FDA clears updated vaccines, as expected, then the CDC would issue guidance on which populations could or should receive one.
Update Once a Year?
For influenza, officials meet once a year to examine how the virus has evolved and inform manufacturers of which strain should be targeted. Companies then manufacture updated versions of the vaccine, which are used that year. Some years, the prediction is wrong.World Health Organization (WHO) experts plan to meet twice a year to consider COVID-19 data and decide whether to recommend updated vaccines. The FDA will “probably follow WHO here and look at this twice yearly as well,” Dr. Peter Marks, a top FDA official, said.
At another point, though, he said that updates would likely happen no more than once a year.
“We’re only going to have one update per year, barring a heroic effort to deal with a strain that pops up that is essentially so different that it requires us to mobilize tremendous resources,” he said.
He also said the COVID-19 vaccine is not like the vaccine against measles, mumps, and rubella, which is not updated.
“This is not going to be the final formula for this vaccine forevermore. It’s probably going to require another update,” he said.
One of the goals of updating the vaccine composition is to convince more people to get vaccinated, according to Marks and some of the panelists.
The initial vaccination campaign led to about four in every five Americans getting at least one dose, but just 17 percent have received a bivalent shot.
That’s likely due to how Omicron and now XBB cause less severe illness than earlier strains, Dr. Cody Meissner, a panel member who is a professor of pediatrics and medicine at Dartmouth College’s Geisel School of Medicine.
“If this virus continues to decline in disease severity and rates and approaches the four seasonal coronaviruses, then it’s going to be difficult to convince many people to get this vaccine,” Meissner said.