As word circulates around whether or not an a COVID-19 vaccine booster shot will be necessary in coming months, Chicago's top doctor said she could see an additional dose being required by fall.
The need for a booster shot likely won't depend on how effective any of the three COVID vaccines are, according to Chicago Department of Public Health Commissioner Dr. Allison Arwady. Rather, another shot could aid in protecting against any possible new variants that could arise during the summer.
"Where we would need a booster is not because one of the three vaccines we have lost how effective it is," Arwady said. "Most likely it's more that we could see a new variant emerge that the vaccines are no longer protective against, and that could happen just in the next few months."
She noted that the vaccine companies would need to gain additional research before bringing a potential booster to the U.S. Food and Drug Administration, which she says could take two to three months.
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Companies behind the vaccines currently being administered in the U.S. have already started investigating potential booster shots as variants of the coronavirus spread nationwide.
"We continue to try to project what will happen," Illinois Department of Public Health Director Dr. Ngozi Ezike said Monday. "Again, the boosters, we're not even sure, you know, when that will be, if that will be, if it'll be new vaccines or the same vaccines."
But preparations for a booster shot are already underway.
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"Requiring additional shots in the future is obviously a foreseeable potential event," Andy Slavitt, senior advisor to President Joe Biden's COVID response team, said during a mid-April press briefing. "I want to emphasize that while there is certainly speculation about this, that is far from saying that is what's going to happen."
White House chief advisor Dr. Anthony Fauci also said during an interview with MSNBC's Medhi Hasan last month that people may need to get booster shots in a year.
Though studies have shown the current vaccines provide protection against known variants so far, they may not be as effective against newer strains.
Boosters and new versions of vaccines that target the variants are already being explored.
Pfizer CEO Albert Bourla previously said people will "likely" need a third dose within 12 months of getting fully vaccinated. Pfizer-BioNTech have already been testing a third booster shot on fully vaccinated people.
"The flexibility of our proprietary mRNA vaccine platform allows us to technically develop booster vaccines within weeks, if needed," Ugur Sahin, CEO and co-founder of BioNTech, said in a release.
Moderna is also testing a potential third dose of its current vaccine, and a possible booster shot specifically targeting a South African variant.
Citing early data, the company recently said the booster vaccine generated a promising immune response against the B.1.351 and P.1 variants first identified in South Africa and Brazil, respectively.
Meanwhile, Johnson & Johnson CEO Alex Gorsky said during an interview with CNBC's "Squawk Box" in March that the company is well-positioned to adapt its vaccine for variants, and is working on developing software that will "help address some of these new and emerging variants."
Some experts have speculated that the coronavirus vaccine could become an annual event, similar to the flu vaccine. But many acknowledge that there's still much left to determine.
"We already know the number of people that get their annual flu shot from pharmacies, so that's not a new invention or creation, but we need it for this pandemic," Ezike said Monday. "And going forward, we will continue to make vaccines as accessible as possible to just erase barriers and obstacles, so that people can get the protection they need as quickly and effectively and equitably as possible."