JNJ-78436735 is Janssen Pharmaceuticals Companies of Johnson & Johnson's vaccine. It is a one-dose vaccine for individuals 18 and over, with full protection 28 days after vaccination. The vaccine has been shown to be effective at preventing severe COVID-19 illness, hospitalization, and death. (Photo courtesy of Janssen Pharmaceuticals)

The federal Centers for Disease Control and Prevention’s advisory panel unanimously voted Friday to support COVID-19 vaccine boosters for immunocompromised people.

The guidance, which CDC Director Rochelle Walensky is expected to formally support on Friday, applies to people who have received the two-dose series of vaccines developed by Pfizer-BioNTech and Moderna.

Following Walensky’s approval, booster shots could be in arms as soon as this weekend. The U.S. Food and Drug Administration also issued its approval Thursday night of booster shots for people with weakened immune systems.

According to the CDC, some people who may be recommended to get a third vaccine dose include people who are being treated for cancer, organ transplant recipients, people with HIV and people actively being treated with immunosuppressant qualities like chemotherapeutic drugs.

Roughly 7 million U.S. adults have a weakened immune system and as such are more likely to suffer so-called breakthrough COVID-19 infections after they’ve been fully vaccinated, as their antibody response is not as robust as that of people with fully functional immune systems.