The likelihood of a COVID-19 booster shot is becoming more confirmed and now Pfizer and Moderna may have a timeline for when people will need it.
"When the level of protection starts to dwindle down, as happens over time, or when we start seeing more breakthrough infections, you're going to see boosters," said Dr. Anthony Fauci.
That timeline appears to be several months after initial doses, according to the CEOs of Pfizer and Moderna, Axios reports.
"The data that I see coming, they are supporting the notion that likely there will be a need for a booster somewhere between eight and 12 months," Pfizer CEO Albert Bourla said Wednesday during an Axios event.
Moderna told Axios they expect a similar timeline.
"People at highest risks (elderly, healthcare workers) were vaccinated in December/January," Moderna CEO Stéphane Bancel wrote in an email. "So I would do [a] September start for those at highest risk."
While experts do not know how long the protection from the COVID-19 vaccines will last, there is no evidence yet that efficiency is fading. It is common for vaccines to fade over time, and it won't happen overnight. Companies that have approved vaccines are tracking antibody and protection levels of trial participants to see how protection changes over time.
Booster shots could also be updated to better address variants that are identified in the future, similar to the flu shot each year.
Pfizer's COVID-19 vaccine has been given FDA emergency use authorization for Americans as young as 12, and Dr. Fauci believes younger kids will be able to get the vaccine by the end of the year.
Robin Dich and Alex Livingston from Newsy.com contributed to this story.