The U.S. Food and Drug Administration’s vaccine experts unanimously recommended an emergency use permission of a booster dose of Moderna’s Covid-19 vaccine.

The FDA’s Vaccines and Related Biological Products Advisory Committee concluded Thursday that using a booster dose six months after the initial shots would be safe and beneficial in some patients.

 Moderna had requested emergency use authorization for a half dosage of their vaccine to be administered as a booster for specific individuals.

All 19 members of the committee agreed that a 50-microgram booster dose, half the size of the 100-microgram doses used in the primary series of the two-dose vaccine, should be given at least six months after the second dose.

They agreed that the additional dose should only be given to certain people, namely people 65 and older, people 18 to 64 who are at high risk of severe Covid-19 symptoms, and people 18 to 64 whose exposure to the coronavirus in their settings or jobs puts them at risk for Covid-19 complications or severe disease.

The groups permitted to receive a booster dose of Pfizer’s mRNA vaccine were reflected in Moderna’s EUA request. For some immune-compromised individuals, third doses of the Moderna and Pfizer Covid-19 vaccines have previously been approved.

Dr. Eric Rubin, the editor in chief of the New England Journal Of Medicine, said that despite the imperfect data, he thinks that everyone should learn to work with what they have. Health care workers should be protected from infection, even if they’re not sick, he added.

The VRBPAC’s meeting will continue on Friday when members will vote on whether to approve the use of boosters for Johnson & Johnson’s vaccine. The agency’s committee of independent advisers is responsible for reviewing and making recommendations on vaccines.

After the recent vote, members were asked if they would like to widen the group to include younger members. Several said they were not convinced that they needed to do much more.

Dr. Paul Offit, who heads the Vaccine Education Center, said that he doesn’t agree with giving vaccines to kids under 18 years old. He also criticized the use of terms such as breakthrough and implying that people are not safe without a third shot.