The boosters have been approved for all adults aged 18 and older and will be given two months after the first dose.
It comes exactly one day after the Vaccines and Related Biological Products Advisory Committee (VRBPAC) recommended approval of boosters for the Moderna vaccine.
However, third doses of the Moderna were only recommended for those aged 65 and older or at high risk due to underlying conditions or their jobs.
The vote comes after Johnson & Johnson announced last month showing a booster shot of its COVID-19 vaccine is highly protective against severe illness.
The FDA’s advisory committee unanimously voted to recommend approval of Covid booster shots of Johnson & Johnson’s vaccine on Friday. Pictured: Johnson & Johnson COVID-19 vaccine on a table at a vaccination clinic in Los Angeles, May 2021
The booster shot will be available to all adults aged 18 and older and given two months after the first dose. Pictured: Dr Richard Schwartz receives a Pfizer Covid vaccine booster at Teaching Center LIJ Medical Center in New York, October 6
Last month, J&J said a second shot given about two months after the first increased effectiveness to 94 percent against symptomatic disease.
This compares to 70 percent protection seen with a single dose.
The New Brunswick, New Jersey-based firm published details of three studies examining different aspects of its vaccine.
The first study was a Phase III two-dose trial of up to 30,000 participants looking at the effectiveness of a second dose given 56 days after the first in adults 18 and older.
The first study found that a booster shot was 94 percent effective against symptomatic COVID-19 in the U.S. and 100 percent effective against critical illness at least 14 days post-vaccination.
There was only one case of COVID-19 in the vaccine group and 14 in the placebo group.
J&J said that a booster given two months after the first dose increased antibody levels between four-fold and six-fold.
When given six months after the first dose, antibody levels shot up nine-fold after one week and 12-fold after four weeks.
These increases were seen regardless of age.
Side effects with two doses were comparable to those seen in studies with the single-dose vaccine.
The recommended approval is very different than that given to the Pfizer-BioNTech vaccines.
Last month, Pfizer was only approved for adults aged 65 and older and those aged 18 to 64 at high risk due to underlying conditions or their jobs.
Modena received recommended approval for the same groups on Thursday but has yet to be authorized by the FDA or recommended by the Centers for Disease Control and Prevention’s (CDC) advisory committee, two key steps before it can be rolled out.
However, J&J is the first firm to have a booster shot available for all recipients regardless of age, comorbidities or other risk factors.
It wasn’t clear that the FDA committee would recommend approval of the J&J vaccine, however.
An FDA report released on Thursday did not show confidence in the need for the booster, because data was lacking, including limited evidence that a second shot would help against the highly contagious Delta variant.