Johnson and Johnson: Second dose of COVID-19 vaccine boosts antibodies

Trials have shown a booster of the single-dose vaccine produces a robust increase in spike-binding antibodies.

As the country gears up for the administration of COVID-19 boosters, Johnson and Johnson has released data suggesting a second shot of their single-dose vaccine increases spike-binding antibodies.

According to a news release, interim Phase 1/2a data showed that the initial dose generated neutralizing antibody responses for eight months after it was administered. The studies show that an additional dose of the vaccine generated a rapid and robust increase in spike-binding antibodies nine times higher than those seen 28 days after the primary vaccination.

Large increases in these antibody responses were seen in trial participants between 18 and 55 and in participants 65 and older who received a smaller booster dose, the release says.

“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,” Mathai Mammen, MD, PhD, global head of Janssen Research & Development at Johnson & Johnson, says in the release. “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. We look forward to discussing with public health officials a potential strategy for our Johnson & Johnson COVID-19 vaccine, boosting eight months or longer after the primary single-dose vaccination.”

The release says that Johnson and Johnson is currently engaging with the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and European drug authorities regarding the booster shots and will continue to generate and evaluate data from ongoing trials.

Boosters are coming

The federal government will make third doses of the Pfizer and Moderna COVID-19 vaccines available to all American next month.

Reportedly, the decision came after the administration reviewed a wide array of data and concluded that the additional shots are needed to maintain immunity against COVID-19. For now, the administration will not recommend an additional dose for those who received the Johnson and Johnson vaccine as the government still reviews data.

The move comes as the Delta variant has driven up the numbers of COVID-19 infections across the country and has led to a rash of breakthrough infections among the already vaccinated.

Earlier in the month, when the move was hinted at by administration officials, they said it would be dependent on the Food and Drug Administration (FDA) authorization, but there’s been no reports of a timeline for such authorization.

The agency has already expanded the emergency use authorization for the Pfizer and Moderna two-dose vaccines to allow for a third dose to the estimated 3 percent of Americans, or about 9 million, with weakened immune systems. The vaccines are believed to be less effective in this group of people, but the initial hope was that widespread vaccinations would protect the immunocompromised population. As of Aug. 25, slightly more than half of eligible Americans, 167.1 million, have been fully vaccinated.