J&J says second shot boosts protection

Amid the debate over the necessity of booster doses, Johnson & Johnson says a second shot of its COVID-19 vaccine boosts protection.

The drug maker said Tuesday a booster shot administered about two months after the first increased its effectiveness to 94% in the United States against moderate to severe forms of the disease. That’s much higher than a single dose, which offers 70% protection.

And the wider the gap between the two shots, the more effective the booster. J&J said a booster given two months after the first dose increased antibody levels four to six times. But when given six months after the first, antibody levels rocketed 12-fold.

The data has not been peer reviewed. But it will help J&J – the only producer of a single-shot coronavirus vaccine - make its case to U.S. regulators for a booster shot. The company says it has submitted its data to the Food & Drug Administration.

So far, only Pfizer and BioNTech have submitted sufficient data for evaluation on booster shots. U.S. regulators could authorize their booster shot for older and some high-risk Americans early this week in time for the government to roll them out by Friday.

Shares of Johnson & Johnson rose in early trading Tuesday.