Aunque la designación de COVID-19 como emergencia nacional y de...Leer más
FDA Panel Backs Shift Toward One-Dose COVID Shot
A panel of advisers to the FDA unanimously supported an effort today to simplify COVID-19 vaccinations, with the aim of developing a one-dose approach — perhaps annually — for the general population.
The FDA is looking to give clearer direction to vaccine makers about future development of COVID-19 vaccines. The plan is to narrow down the current complex landscape of options for vaccinations, and thus help increase use of these shots.
COVID remains a serious threat, causing about 4000 deaths a week recently, according to the Centers for Disease Control and Prevention (CDC).
The 21 Members of the Vaccines and Related Biological Products Advisory Committee (VRBPAC) unanimously voted “yes” on a single question posed by the FDA:
“Does the committee recommend harmonizing the vaccine strain composition of primary series and booster doses in the US to a single composition, e.g., the composition for all vaccines administered currently would be a bivalent vaccine (Original plus Omicron BA.4/BA.5)?”
In other words, would it be better to have one vaccine potentially combining multiple strains of the virus, instead of multiple vaccines — such as a two-shot primary series followed by a booster containing different combinations of viral strains.
The FDA will consider the panel’s advice as it outlines new strategies for keeping ahead of the evolving virus.
In explaining their support for the FDA plan, panel members said they hoped that a simpler regimen would aid in persuading more people to get COVID vaccines.
Pamela McInnes, DDS, MSc, noted that it’s difficult to explain to many people that the vaccine worked to protect them from more severe illness if they contract COVID after getting vaccinated.
“That is a real challenge,” said McInness, a retired deputy director of the National Center for Advancing Translational Sciences at the National Institutes of Health.
“The message that you would have gotten more sick and landed in the hospital resonates with me, but I’m not sure if it resonates with” many people who become infected, she said.
In the briefing document for the meeting, the FDA outlined a plan for transitioning from the current complex landscape of COVID-19 vaccines to a single vaccine-composition for the primary series and booster vaccination.
This would require:
- Harmonizing the strain composition of all COVID-19 vaccines (mRNA, protein-based)
- Simplifying the immunization schedule for future vaccination campaigns to administer a two-dose series in certain young children and in older adults and persons with compromised immunity, and only one dose in all other individuals
- Establishing a process for vaccine strain selection recommendations, similar in many ways to that used for seasonal influenza vaccines, based on prevailing and predicted variants that would take place by June to allow for vaccine production by September.
During the discussion, though, questions arose about the June target date. Given the production schedule for some vaccines, that date might need to shift, said Jerry Weir, PhD, director of the division of viral products at FDA’s Center for Biologics Evaluation and Research.
“We’re all just going to have to maintain flexibility,” Weir said, adding that there is not yet a “good pattern” established for updating these vaccines.
Increasing Vaccination Rates
There was broad consensus about the need to boost public support for COVID-19 vaccinations. While about 81% of the US population has had at least one dose of this vaccine, only 15.3% have had an updated bivalent booster dose, according to the CDC.
“Anything that results in better public communication would be extremely valuable,” said committee member Henry H. Bernstein, DO, MHCM, of the Zucker School of Medicine at Hofstra/Northwell Health in Hempstead, New York.
But it’s unclear what expectations will be prioritized for the COVID vaccine program, he said.
“Realistically, I don’t think we can have it all — less infection, less transmission, less severe disease, and less long COVID,” Bernstein said. “And that seems to be a major challenge for public messaging.”
Panelists Press for More Data
Other committee members also pressed for clearer targets in evaluating the goals for COVID vaccines, and for more robust data.
Like his fellow VRBPAC members, Cody Meissner, MD, of Dartmouth’s Geisel School of Medicine, supported a move toward harmonizing the strains used in different companies’ vaccines. But he added that it wasn’t clear yet how frequently they should be administered.
“We need to see what happens with disease burden,” Meissner said, “We may or may not need annual vaccination. It’s just awfully early, it seems to me, in this process to answer that question.”
Among those serving on VRBPAC Thursday was one of the FDA’s more vocal critics on these points, Paul A. Offit, MD, a vaccine expert from Children’s Hospital of Philadelphia. Offit, for example, joined former FDA officials in writing a November opinion article for the Washington Post, arguing that the evidence for boosters for healthy younger adults was not strong.
At Thursday’s meeting, he supported the drive toward simplification of COVID vaccine schedules, while arguing for more data about how well these products are working.
“This virus is going to be with us for years, if not decades, and there will always be vulnerable groups who are going to be hospitalized and killed by the virus,” Offit said.
The CDC needs to provide more information about the characteristics of people being hospitalized with COVID infections, including their ages and comorbidities as well as details about their vaccine history, he said. In addition, academic researchers should provide a clearer picture of what immunological predictors are at play in increasing people’s risk from COVID.
“Then and only then can we really best make the decision about who gets vaccinated with what and when,” Offit said.
VRBPAC member Ofer Levy, MD, PhD, also urged the FDA to press for a collection of more robust and detailed information about the immune response to COVID-19 vaccinations, such as a deeper look at what’s happening with antibodies.
“I hope FDA will continue to reflect on how to best take this information forward, and encourage –or require —sponsors to gather more information in a standardized way across these different arms of the human immune system,” he said. “So we keep learning and keep doing this better.”
In recapping the panel’s suggestions at the end of the meeting, Peter Marks, MD, PhD, the director of the FDA’s Center for Biologics Evaluation and Research, addressed the requests made during the day’s meeting about better data on how the vaccines work.
“We heard loud and clear that we need to use a data-driven approach to get to the simplest possible scheme that we can for vaccination,” Marks said. “And it should be as simple as possible but not over simplified, a little bit like they say about Mozart’s music.”
The study was funded by Merck. Smith reports receiving grant funding from Merck. Jones reports no relevant financial relationships.