Americans need to be prepared for the possibility that they may feel a little unwell after they get a coronavirus vaccine, if one is authorized, members of a US Centers for Disease Control and Prevention advisory committee said Monday.

The CDC’s Advisory Committee on Immunization Practices met to discuss whether to recommend use of any Covid-19 vaccine that the US Food and Drug Administration might authorize.

Volunteers in vaccine trials have reported they frequently feel flu-like effects after getting vaccinated, and members of the ACIP — as well as liaison representatives who take part in the discussion — said that could affect people’s willingness to get vaccinated in the first place, or to get the second dose of the two-vaccine regimen.

“As a practicing physician, I have got to be sure my patients will come back for the second dose. We really have got to make patients aware that this is not going to be a walk in the park,” Dr. Sandra Fryhofer of the Emory University School of Medicine, representing the American Medical Association, told the meeting.