J&J’s extra doses will be for all adults aged 18 and older while Modena’s third shot will only be for those aged 65 and older or at high risk due to underlying conditions or their jobs.
It comes a week after the FDA’s advisory committee recommended that officials approved the two companies’ booster doses.
The federal health agency will also allow fully vaccinated Americans to ‘mix and match’ Covid vaccines and booster shots.
This means people can receive a booster made by a company that is different than the one that made the vaccine they initially received.
The next and final step before the extra doses can be rolled out will be authorization from the Centers for Disease Control and Prevention’s (CDC) advisory committee, which is expected to occur on Thursday.
The FDA has authorized booster shots for the Moderna and Johnson & Johnson COVID-19 vaccines. Pictured: Nurse Elyse Isopo receives COVID-19 Pfizer vaccine booster at Teaching Center LIJ Medical Center in New York, September 23
Moderna’s (left) third dose is only authorized for those aged 65 and older or those between ages 18 and 64 at high risk due to underlying conditions or their jobs. J&J’s (right) booster shot is approved for all American adults aged 18 and older
‘Today’s actions demonstrate our commitment to public health in proactively fighting against the COVID-19 pandemic,’ said Acting FDA Commissioner Dr Janet Woodcock, in a statement.
‘As the pandemic continues to impact the country, science has shown that vaccination continues to be the safest and most effective way to prevent COVID-19, including the most serious consequences of the disease, such as hospitalization and death.
‘The available data suggest waning immunity in some populations who are fully vaccinated. The availability of these authorized boosters is important for continued protection against COVID-19 disease.’
J&J’s authorization comes after the company published data in September looking at the effectiveness of a second dose given 56 days after the first in adults 18 and older.
Results showed a booster shot was 94 percent effective against symptomatic COVID-19 and 100 percent effective against critical illness at least 14 days post-vaccination.
This compares to 70 percent protection seen with a single dose.
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.
In the case of Moderna, the company released data in September showing people who received its COVID-19 vaccine last year are nearly twice as likely to get a breakthrough infection compared to those recently vaccinated.
There were 88 breakthrough cases of COVID-19 among Americans vaccinated from December 2020 to March 2021.
Comparatively, there were 162 cases – 1.8 times as many – among those vaccinated between July 2020 and December 2020.
The Cambridge, Massachusetts-based company said the data provided evidence for giving booster doses to fully vaccinated people.
The authorization of ‘mix and match’ boosters comes after researchers from the National Institutes of Health (NIH) presented data at an FDA advisory committee meeting on Friday showing people who got Johnson & Johnson’s Covid vaccine had higher antibody levels if they get a Pfizer-BioNTech or Moderna booster shot.
The NIH presented data last week showing the J&J booster raised antibody levels in J&J recipients four-fold (left) over two weeks while Pfizer’s booster raised levels 45-fold (right) and the Moderna booster spiked levels 76-fold (center)
Moderna’s booster was also found to raise antibody levels higher among Pfizer recipients than Pfizer’s third dose – 32 fold (center) compared to 21-fold (right)
The report found that when recipients of the one-shot J&J vaccine received a second dose, their antibody levels increased four-fold over two weeks.
Comparatively, when they received a Moderna booster, their antibody levels spiked 76-fold over the same time period.
A booster shot of the Pfizer vaccine also raised antibody levels 45-fold over the course of two weeks – higher than the J&J shot, but not as high as the Moderna shot.
What’s more, the Moderna booster was also found to raise antibody levels higher Pfizer recipients.
Americans who received two doses of the Pfizer saw their antibody levels increase 21-fold after a third Pfizer shot.
But those given the Moderna booster had antibody levels raised 32-fold over the span of 14 days.