There’s no evidence yet that shows COVID-19 vaccine booster shots are needed, a working group for the Centers for Disease Control and Prevention said Wednesday.

The situation, however, could change, Dr. Sara Oliver, co-lead of the working group, told the CDC’s Advisory Committee on Immunization Practices. The group will “continue to monitor” data, she said.

"For recommendations around booster doses of COVID-19 vaccine, we need to not only have information around the risks of COVID complications and risk of exposure but also the risk of waning immunities and risk of COVID variants," Oliver said.

Oliver said additional shots could eventually be needed for the general population, but there’s a chance they might only be recommended for certain populations — among the ones closely being watched are residents of long-term care facilities, people 65 years of age or older, health care workers and the immunocompromised. 

Oliver said the working group recommended that the CDC only call for boosters if there is “evidence of declining protection” such as vaccines losing their effectiveness over time or variants emerging that are resistant to the initial shots. Global vaccine availability should also be considered, she said.

The advisory panel agreed that it’s too soon to recommend boosters.

“I think the only thing we can do at this moment is, if we start to see an uptick in reinfection in people, or new infections in people who have been vaccinated, that's our clue that we need to move quickly,” said committee member Dr. Sharon Frey.