According to three top US Food and Drug Administration officials, the pandemic coronavirus is likely to become a seasonal respiratory virus, much like the flu, which requires annual boosters each fall.
In a comment piece published this week in the medical journal JAMA, the officials are calling for seasonal shooting and warning that preparations for this winter’s potential wave should begin no later than next month.
“The timeline for determining the composition of the COVID-19 vaccine for the 2022-2023 season, to be used in addition to the seasonal flu vaccine for administration in the Northern Hemisphere from approximately October, has been compressed due to the time required to manufacture of the necessary doses,” the officials write. “A composition decision must be made in the US before June 2022.”
The piece was written by top FDA vaccine regulator Peter Marks, FDA chief deputy commissioner Janet Woodcock and FDA commissioner Robert Califf.
On the one hand, the urgency to prepare for the fall can be caution. But it comes well before the data settles on many aspects of their argument, most notably whether SARS-CoV-2 will become seasonal and whether boosters will be needed.
Insecurity
“The jury is still out on how seasonal this virus will become,” said Dr. Mike Ryan, executive director of the World Health Organization’s Health Emergencies Program, said in a news conference Wednesday. The transmission dynamics will depend on how well people are protected at any given time (by vaccination and/or previous infection), which variant spreads and how people behave, such as invading, he explained. However, he noted that it is reasonable to assume that the virus is transmitted more quickly if people are close together indoors.
In the event of more transmission this fall, it’s still unclear whether additional boosters are needed, as Katherine O’Brien, director of WHO’s division of immunization, vaccines and biologics, noted in the briefing. “We’re in a pretty limited space in terms of data,” she said. There is little data so far, and what we do have is mainly on mRNA vaccines — one of many vaccine platforms in use worldwide — and from high-income countries like the US and Israel.
Those data point to a short-term benefit in terms of hospitalizations, she said, but the information is limited and not to a point where the WHO can recommend future boosters. For now, she said, the agency is focused on continuing to get primary doses and existing boosters for priority groups — health professionals and older adults — in countries around the world.
New normal
But the FDA’s Marks, Woodcock and Califf note that there is no time left to prepare for fall, given the lead time required to manufacture the doses. Rather than solid evidence, the FDA will have to rely on available data and predictive models that can attempt to explain declining vaccination protection and winter infection and transmission patterns. The pending decision will also have to be made “with the understanding that there will be some inherent residual uncertainty about the further evolution of SARS-CoV-2,” they write.
That uncertainty is already looming large with the upcoming decision. Omicron subvariants continue to evolve rapidly, demonstrating newfound abilities to evade ommicron-based immune responses that have evolved in recent months. The evolution of the viruses raises concerns that all ommicron-based vaccines designed this summer could be obsolete by the fall.
Still, the FDA appears to have set its sights on an ommicron-based booster. “To date, the original, or prototype, vaccine composition used is quite good at protecting against severe effects of COVID-19,” the officials write. “However, greater depth and duration of protection can be achieved with a vaccine that currently covers circulating variants.”
Whatever vaccine formulation is chosen, fall boosters will provide an opportunity to increase protection at the population level, they argue. And with the plan in motion, “society is moving towards a new norm that may well include annual COVID-19 vaccination alongside seasonal flu vaccination.”
