Johnson & Johnson announced Tuesday that its COVID-19 booster shot is 94% effective when administered two months after the first dose.

They say it also increases antibody levels four to six times higher than one shot alone.

The company also said that those who got the booster tolerated it well - and side effects were generally consistent with those seen after the initial dose.

The Johnson & Johnson vaccine was administered Tuesday at Wantagh High School from Mount Sinai South Nassau’s Vaxmobile.

Amber Vitale, a nurse practitioner with Mount Sinai South Nassau says health care workers giving the COVID-19 vaccine shot will have to wait for further guidance from the CDC, FDA and New York State Department of Health before making any changes to the doses they're giving.

"It's important to still mask, still do social distancing, but right now you just got to hold tight till we get that recommendation from everybody," says Vitale.

Right now, the one-shot Johnson & Johnson vaccine is only being given under emergency use authorization by the FDA.

According to the CDC, more than 14 million Americans have received the shot.

When a booster of the Johnson & Johnson COVID-19 vaccine was given six months after the single shot, antibody levels increased nine-fold one week after the booster and continued to climb to 12-fold higher four weeks after the booster.

The report by the company has not been evaluated or reviewed by other scientists or federal agency with the authority to authorize a second shot.

Johnson & Johnson says it has given its data to the Food and Drug Administration and plans to also submit it to the World Health Organization.