Researchers say any of the approved COVID-19 vaccines will work as a booster.
British researchers published their findings in "The Lancet."
They looked at six different COVID-19 vaccines and found they all produce a strong immune system response and work safely.
Researchers say the new information gives booster programs flexibility.
As we meet more COVID variants, researchers say it's possible a vaccine will be needed every year.
Meanwhile, Pfizer reps say their vaccine should adapt to respond to the omicron variant.
But that the mutation may still infect vaccinated people.
So, the company's CEO says it's likely vaccinations will be the norm.
He adds, a new vaccine will likely be needed to fight the new variant.
They're still doing research on this potential vaccine.