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Johnson & Johnson says booster shot provides ‘rapid and robust’ COVID-19 antibody increase

Johnson & Johnson said a booster shot of its vaccine provides a nine-fold increase in COVID-19 antibodies.
Free COVID-19 vaccination clinic at Jetport
A nurse prepares a syringe of the Johnson & Johnson COVID-19 vaccine at a clinic in Portland, Maine.Ben McCanna / Portland Press Herald via Getty Images

Johnson & Johnson said 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 one-shot 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.

Mathai Mammen, global head of Janssen Research & Development at Johnson & Johnson, said the company was looking “forward to discussing with public health officials a potential strategy” for deploying a J&J booster shot.

The drugmaker said it was “engaging” with the Food and Drug Administration and the Centers for Disease Control and Prevention, as well as the European Medicines Agency, which is the main regulator in Europe, and the World Health Organization, about using its shot as a booster.

Boosters are being planned in the United States as early as the fall for those who got the two-shot Pfizer-BioNTech and Moderna vaccines.

This is a breaking news story. Please check back for more updates. A version of this story was originally published on