J&J says COVID-19 booster jab generates strong antibody response

Johnson & Johnson said its booster dose of COVID-19 vaccine provided a rapid and strong increase in neutralising antibodies against the spike protein of SARS-CoV-2 virus, supporting the use of a second shot among people who have had its single-dose vaccine.

In anticipation of the potential need for boosters, J&J conducted two Phase 1/2 studies in individuals vaccinated with its single-shot vaccine.

"We have established that a single shot of our COVID-19 vaccine generates strong and robust immune responses that are durable and persistent through eight months," said Mathai Mammen, Global Head, Janssen Research & Development, Johnson & Johnson.

"With these new data, we also see that a booster dose of the Johnson & Johnson COVID-19 vaccine further increases antibody responses among study participants who had previously received our vaccine."

The new interim data shows that a booster dose generated a rapid and robust increase in spike-binding antibodies, nine-fold higher than 28 days after the single-dose vaccination.