The debate over the need for COVID-19 booster shots continues unabated – and the country is no closer to a definitive answer today than it was months ago.

Earlier in the month, a Food and Drug Administration advisory panel chose not to recommend the extra dose to the general population, limiting it only to people aged 65 and up and people at high risk of severe illness. The FDA’s take clashed with President Biden’s original announcement that the federal government would begin rolling out booster shots to all Americans by September 20.

The mixed messaging around booster shots adds yet another layer of confusion to the federal government’s COVID-19 response. It joins issues stemming from unclear communication, flip-flopping on masking guidance and not properly tracking breakthrough infections on the list.

But public health experts believe the arduous scientific process that will ultimately determine whether booster shots are needed is relatively normal – and an important part of ensuring safety and confidence. The difference is that, pre-COVID, those scientific committees weren’t as closely watched by the public.

“This is the normal part of the checks and balances that this process goes through,” said Dr. Waleed Javaid, an epidemiologist and professor of medicine at Icahn School of Medicine at Mount Sinai. “There’s a process that has to be followed for safety and security. It does take time for all these recommendations to be made, because there’s a lot of data the CDC and FDA have to go through to make recommendations that are applicable to the public.”

Centers for Disease Control and Prevention committee members have so far reviewed Pfizer data from Israel, which show that immunity decreases over time. Those data also show that a third shot boosted antibody levels and improved immunity. But a variety of other studies have noted that protection from the original two-shot administration is strong enough to keep people safe from severe illness or death – as well as the Delta variant – months later.

One of the complications in interpreting that data to determine policy is that there’s no set definition of “severe illness.” Israel, for example, defines it as anything involving a higher respiratory rate and an oxygen level below 94%. The CDC, on the other hand, views severe illness through the lens of hospitalizations.

However the CDC advisors weigh in on booster shots, their recommendations may well change with time, Javaid noted. He pointed out that the annual flu vaccine is adjusted every year to target changing strains of the virus, which mutate significantly enough that a one-and-done vaccine will not suffice. The COVID-19 vaccine, on the other hand, appears to maintain decent protection against variants of the virus, including Delta.

For now, booster shots don’t appear necessary for the general population. Whether we’ll need them annually as the pandemic becomes endemic is something that only time – and more data – will tell.

“The longevity of that protection is something we’ll know in the next few months or year,” Javaid said. “One of the things that the data will show is whether boosting our immune systems will help. The other thing will be what other modalities do we need to do to prevent rising cases. Whether those are annual boosters is something that remains to be seen.”

Putting aside the booster conversation, Javaid pointed out that the greater concern remains the large swaths of the country that remain unvaccinated.

“Look at New York City versus Texas,” he said. “The rates we’re seeing show us it’s likely due to lower vaccination rates and different social policies when it comes to masking and other precautions.”

“Once we are on the other side, we’ll know better what worked better and what didn’t,” Javaid continued. “We know our way out of COVID is going to be vaccines, because that was our way out of polio, smallpox and measles. The only thing we don’t know is when.”