The United States Food and Drug Administration Independent Advisory Committee on Vaccines and Related Biologicals (VRBPAC) voted on Tuesday to support the recommendation to include a specific component of Omicron for a Covid-19 booster vaccine.
Twenty-one voting members of the FDA’s Independent Panel voted 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?”
Nineteen of the members voted yes, two voted no.
“I voted for Omicron because I think broadening immunity is important,” said Dr. Wayne Marasco, professor of medicine in the Dana-Farber Department of Cancer Immunology and Virology. Cancer Institute Harvard Medical School. “I will say I was quite impressed today that we could do better.”
“I think it’s a step in the right direction, but we have to reassess that as we move forward,” he added.
The committee reasoned that a modified vaccine would provide broader protection to match the strain of coronavirus currently in circulation.
Two subvariants of Omicron, BA.4 and BA.5, now dominate the transmission of Covid-19 in the United States, according to the United States Centers for Disease Control and Prevention.
This means that the Covid-19 vaccine the United States will receive in the future will be different. The committee does not determine how. The committee was not asked to vote on which subline to include or whether the booster should be a bivalent or monovalent vaccine.
Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said there will be a conversation going forward about who needs another booster and what that booster will look like. Marks noted that a bivalent vaccine targeting the BA.4 and BA.5 Omicron subvariants appeared to be the committee’s preference.
When the FDA’s independent vaccine advisers met in April, they agreed they needed to develop a framework for how the country can keep pace with the virus with an appropriate vaccine strategy. The FDA said in May that the “new normal” could include an annual Covid-19 and flu vaccine for people in the fall. Cases are expected to rise again in the fall and winter.
Dr Arnold Monto, acting chairman of the Independent Vaccine Advisers, suggested that figuring out what goes into the recall won’t be easy.
“I think we’ve done our best in a difficult situation with imperfect data and the inability to say what’s coming after what looks like Omicron wave 4 or 5,” Monto said. “We have reviewed the available options and come up with a set of recommendations and guidance that the FDA can follow.”
Moving forward to create a vaccine to better fight a rapidly changing virus is ‘uncharted territory’
“Looking into the past doesn’t help us much in looking into the future for this virus which has baffled many of us and made predictions almost irrelevant,” Monto added.
Current Covid-19 vaccines are based on the coronavirus that emerged in late 2019, but Pfizer and Moderna have been working on updated versions of the vaccines. Current vaccines are not as effective against circulating variants.
Moderna presented details of its bivalent Covid-19 vaccine booster, mRNA-1273.214, which the company claims elicits “potent” immune responses against Omicron BA.4 and BA.5 subvariants.
Moderna’s bivalent booster vaccine candidate contains components of Moderna’s original Covid-19 vaccine and a vaccine that targets the Omicron variant.
Pfizer/BioNTech also presented the committee with data that showed their two Covid-19 vaccine boosters targeting Omicron showed a significantly higher immune response than its current Covid-19 vaccine. Preliminary laboratory studies suggest that the vaccines could neutralize Omicron BA.4 and BA.5.
Another vaccine maker, Novavax, has committee support for emergency use authorization in the United States, but the FDA has yet to clear its vaccine. Novavax told the committee it was developing updated variant-specific versions of its Covid-19 vaccine as well as a combined Covid-19 and influenza vaccine.
The World Health Organization told the independent committee of vaccine advisers on Tuesday that the vaccination strategy in the future should probably be based on a vaccine that provides as broad a protection as possible, rather than just continuing with it. vaccines that were made against the original. strain that is no longer in circulation.
“I still think it is useful to increase the breath of immunity and I repeat that we are not trying to match what can circulate,” said Dr Kanta Subbarao of the World Collaborating Center of Health for Influenza Reference and Research who works as a professor at the University of Melbourne. “It’s not so much about matching what’s likely to flow because there’s so much uncertainty about the trajectory of that evolution.”
Including Omicron in a future vaccine would help because Omicron is the most distinct of the variants of concern that have emerged, she said, but a stand-alone vaccine that simply matched Omicron would likely not be broad enough to protect against other variants. in the future.
“We are trying to increase the magnitude of the immune response without losing the benefit of the index vaccine that worked so well,” she added.
“We just don’t have enough information about the other variants, but I could argue, based on our experience with influenza, that using a virus to antigenically stimulate as much as possible is a better strategy than something that is halfway there,” she added.
The longer Omicron is the dominant variant circulating in the world, the more likely anything that comes after is from Omicron.
“At least it’s a realistic possibility,” Jerry Weir, director of the viral products division for the Office of Vaccine Research and Review at the FDA, told the committee.
Going forward, as the committee works out how it should create a process for the future if people will need regular reminders of Covid-19, committee members agreed there needs to be better central coordination on studies and on what plans should go forward.
“Without such a plan, we are going to play Whack a Mole as this virus evolves, because it will continue to evolve,” said Dr. Bruce Gellin, committee member and head of global public health strategy at the Foundation. Rockefeller.
“We will improve, but we still have to get ahead,” he said.
Weir, along with the FDA, tried to help the committee keep what they’ve accomplished in perspective.
“I think we’ve made tremendous progress in this whole endeavor over the past few months, but I’ll remind you that the type of parallel track of influenza strain selection, which works very well, was a process that was refined by many people, many years and so we probably have quite a bit of work. It’s a different virus. We have a lot of work to do on the strain selection process for Covid vaccines.”
Several committee members were also concerned about the lack of data regarding what should go into future pediatric vaccines.
“In terms of extrapolating the available data, I’m very hesitant to extrapolate this from adults to children,” said committee member Dr. Archana Chatterjee, who is dean of Chicago Medical School. “I think pediatric studies need to be done and they need to be done now.”
Following the VRBPAC vote, the FDA will rule on the updated vaccine. Then, a panel of independent experts advising the CDC will take a closer look at the available data and recommend to the head of the CDC to decide whether to endorse those recommendations.