A Food and Drug Administration advisory panel recommended a half-dose of the Moderna vaccine as a booster shot against COVID-19 on Thursday, paving the way for possible approval.

The Vaccines and Related Biological Products Advisory Committee unanimously recommended the booster, which Moderna had requested be for emergency use authorization as a half dose of its regular vaccine to prevent COVID-19. The half-dose booster would be given to people who are at least 65 years old and those ages 18 to 64 with health problems or jobs that increase their risk for complications from the disease. The booster would be administered to people who have already been fully vaccinated for at least six months.

Full vaccination with Moderna’s vaccine consists of two 100-microgram injections; the company says a single 50-microgram shot is adequate for a booster to rev up immunity. Moderna has said it wants to offer the half-dose to reduce some of the reactions to the vaccine such as fever and aches, and to have more vaccines available for world supplies.

The recommendation is the first step in the approval process. The FDA will consider the recommendation when it decides on whether to approve the booster. The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices will discuss the booster shot on Oct. 21.

The FDA advisory committee plans to discuss the Janssen/Johnson & Johnson vaccine on Friday for a possible booster recommendation. The agency previously cleared the way for boosters of the Pfizer-BioNTech vaccine for people in high-risk demographic groups.