The FDA panel Friday’s meeting will also address the recall proposed by Johnson & Johnson.
Here are three takeaways from day one of the two-day FDA panel meeting:
Regulators grapple with incomplete data
Despite the unanimous vote, some panelists lamented the meager data they had to rely on to make their decision – and that the previous Pfizer prevented them from going in a different direction with Moderna.
Panel member Patrick Moore, a professor at the Cancer Institute at the University of Pittsburgh, said he had “real issues” with the vote result, based on questions about Moderna’s data quality .
“I just want to explain why I voted yes; it’s more of a hunch rather than a really serious database, ”he said, adding:“ The data itself isn’t solid, but it’s definitely going in a direction that is going. in this direction. ”
Moderna, like other vaccine makers, continues to refer to the antibody response as a sign that people have built up a level of immunity to the coronavirus. But FDA regulators at the meeting admitted they still weren’t sure exactly what the best endpoint, or “correlate of protection,” for measuring the effectiveness and duration of shots is.
University of Pennsylvania vaccine expert Paul Offit, a member of the advisory committee, lamented the use of the antibody response as a measuring stick when data seemed to indicate that immunity increased over time after two doses . He also criticized thinking of mild, asymptomatic breakthrough infections as a sign of failure or a weak vaccine.
“If the goal is to try and protect against the breakthrough infections sadly named asymptomatic infection … then we’re going to talk about getting frequent boosters, which in my opinion is not a reasonable strategy for that. “Offit said. noted.
Another panel member, Cody Meissner of Tufts University School of Medicine, expressed concern about the wording of the recommendation for people whose jobs or living conditions put them at high risk. He argued that while these people are more likely to be exposed to the virus, they are not necessarily more likely to contract serious illness.
“If we can’t defend these recommendations based on the evidence, I think it’s going to make it even harder to get this vaccine into every adult American, and that’s really what we want to do,” he said. declared.
Not all vaccines are created equal
Moderna’s presentation to the committee outlined the company’s rationale for offering a half-dose booster, as opposed to the full doses allowed or proposed for Pfizer and Johnson & Johnson.
“We believe we should vaccinate with the lowest amount of antigen needed to induce an immune response,” said Jacqueline Miller, Moderna’s senior vice president for infectious diseases.
A lower dose is enough to reactivate the body’s immune memory upon the initial vaccination, she said – and it could help expand the global supply of the Moderna vaccine.
Moderna’s half-dose booster didn’t produce the four-fold increase in antibodies that the FDA set as a bar to allow boosts, but Miller said that was because participants in the company’s booster studies had high antibody levels to begin with.
“Subjects who did not meet the definition of a quadruple increase still derive a substantial benefit from the 50 microgram booster dose,” she said.
But some panelists questioned whether the lower dose would provide as long-lasting protection as a full-dose booster.
The data presented by Moderna on the immune response from a full booster dose suggests that immune cells were able to repel the virus even after antibody levels dropped dramatically.
“I don’t know if the FDA has any idea how that will change going from 100 [micrograms] to 50 [micrograms]”said Michael Kurilla, director of the Division of Clinical Innovation at the National Center for Advancing Translation Sciences.” This can have a huge impact on sustainability. “
Global vaccine equity concerns color recall debate
FDA staff tried to block the agency’s vaccine advisers from engaging in broader fairness discussions at recall meetings, but the issue repeatedly surfaced on Thursday.
Miller began his morning presentation by saying the company’s proposed half-dose booster would help expand the global vaccine supply.
Just under half of the world’s population has received at least one dose of a Covid-19 vaccine, but most of those injections have been given in the wealthiest countries. African countries in particular have struggled to vaccinate their populations.
Miller faced sharper questions later in the day about Moderna’s role in reducing the global vaccine deficit from panel member Randy Hawkins, a physician specializing in pulmonary and internal medicine at Charles Drew University and in practice. private.
He insisted to Miller on criticism that Moderna has fallen behind in producing doses for low-income countries, either directly or through the global vaccine assistance program known as COVAX.
“What is Moderna’s commitment to COVAX and the other steps it will take to control the pandemic in disproportionately suffering countries? He asked Miller.
She noted that the company said it would not enforce its intellectual property protections against generic versions of the vaccine during the pandemic and delivered 50 million doses to COVAX in September. Moderna also pledged to build a manufacturing facility in Africa, although she couldn’t say when or where it would open.
“We also plan to deliver 1 billion doses to low-income countries in 2022, and while that includes greater complexity, we are reducing the [booster] dose to 50 micrograms in order to make more vaccines available to the world, ”Miller said.