On Thursday, the Food and Drug Administration’s (FDA) Vaccines and Related Biological Products Advisory Committee unanimously voted to support a new plan simplifying future COVID-19 vaccines, making them similar to annual flu shots.

At the meeting, the advisory panel said that a single annual vaccine would be less confusing and more effective to health care workers and patients alike. 

In a 21 to 0 vote, the panel voted to direct Moderna, Pfizer/BioNTech, and Novavax to “harmonize” the first doses (or primary vaccination series) with the new bivalent booster shots that protect against the original strain of the virus and the newer Omicron variant. 

[Related: What’s really going on with myocarditis and COVID vaccines.]

“This is a consequential meeting to determine if we’ve reached the point in the pandemic that allows for simplifying the use of current COVID-19 vaccines,” said FDA’s David Kaslow, the Director of the Office of Vaccines Research and Review..

Under previous guidance, patients must first get two shots of the original vaccines (spaced weeks apart) and then a bivalent booster tailored to protect against the Omicron variant two months later. 

Members of the advisory panel were also supportive of a new approach that is more like the strategy seen with the annual flu vaccine. Currently, the annual flu vaccine is created each year to match whatever strain of the virus is circulating. This way, patients and healthcare professionals wouldn’t have to worry about how many shots they’ve already gotten and when they were administered. 

“I think this is a reasonable approach. We have to keep reminding ourselves that this is not influenza and we need to keep paying attention to that to make sure we don’t just follow that dogma because we’re used to doing it,” said Bruce Gellin, a temporary voting member of the panel and chief of global public health strategy for the Rockefeller Foundation’s pandemic prevention institute. “We’ll try this this time. I don’t think we’re setting it in stone and we’ll see how it goes. We may need to adjust along the way.”

The agency also addressed varying risks to people with different health status and ages in briefing documents released ahead of the meeting. ​“Most individuals may only need to receive one dose of an approved or authorized COVID-19 vaccine to restore protective immunity for a period of time.  Two doses of an approved or authorized COVID-19 vaccine may be needed to induce the expected protective immunity for those who have a low likelihood of prior exposure (the very young) or those who may not generate a protective immune response (older and immunocompromised individuals),” the FDA wrote.

If a more dangerous COVID variant were to emerge, the FDA said it might reconsider the strain used in the vaccine at other times of the year on an “as-needed and emergent basis.”

Additionally, the timing of annual boosters was debated since COVID-19 hasn’t fallen into a seasonal pattern like the flu—instead  COVID-19 waves emerge periodically year round.  Peter Marks, the director of FDA’s Center for Biologics Evaluation and Research said that there is some evidence SARS-2 is developing a seasonal pattern, but that comment was not universally agreed upon in the meeting. 

“When do we have to worry about the worst overwhelming of the hospitals? It will be when we have influenza, RSV, and potentially covid at the same time,” said Marks.

There is also a debate among scientists if updating the COVID-19 vaccines really does make them more effective and some critics of the FDA’s proposed new strategy argue that investing in developing better vaccines that are more appealing to people, such as intranasal vaccines that could also help curb transmission of the disease, and more robust vaccination campaigns might be more effective.

[Related: Omicron boosters are the future of COVID vaccines in the US.]

“Particularly now when Congress is not allocating new funds for COVID response, we have to be especially judicious in how we spend our money and what would be most cost-effective,” Celine Gounder, a senior fellow at the Kaiser Family Foundation, told NPR. “It’s unclear whether updating the booster formulations and repeatedly boosting people is the most effective approach to controlling COVID at this stage.”

Uptake of vaccine boosters remains slow. Roughly 40 percent of adults over 65 and only 16 percent of those 5 years and older have received the latest COVID-19 booster. 

In a separate development on Thursday, the FDA also halted the emergency use authorization (EUA) of Evusheld, a monoclonal antibody treatment used to prevent COVID-19 in immunocompromised people who are less likely to generate a robust immune response from vaccination. The treatment does not appear to protect against the variants currently circulating.

The agency advised those who are infected to seek medical care and ask about antiviral treatments like Paxlovid, remdesivir, or molnupiravir, which do work against currently circulating variants.