(NBC News) — Johnson & Johnson said on Wednesday that studies show a booster shot of its vaccine provides a “rapid and robust increase” in Covid-19 antibodies when used on people who have already received its first dose.
The interim data showed people who already had been given the J&J vaccine experienced a nine-fold increase in spike-binding antibodies compared with 28 days after the first dose, the drugmaker said in a statement.
That increase was seen in trial participants aged 18 to 55, and in people over 65 who received a lower booster dose, according to the statement. The study was done early in anticipation of the need for boosters, the company said.
The findings have been submitted to the medical preprint publication MedRxiv.