A U.S. Centers for Disease Control and Prevention advisory panel has recommended Pfizer booster shots, but only for those over 65 and some adults with underlying medical conditions.
However, they didn't back the shots for young adults in the high-risk group such as frontline medical workers.
The guidelines voted on by the CDC's Advisory Committee on Immunization Practices still need to be signed off on by agency Director Rochelle Walensky.
This is another step closer to the rollout of the booster shots, but the target group is smaller than expected.
The guideline also only recommends a third dose for those who have already been fully vaccinated by Pfizer's vaccine.