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Johnson & Johnson Covid-19 Booster Shot Boosts Immune Defense, According To FDA Staff


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The Covid-19 vaccine showed signs of significantly strengthening the immune defenses of the study subjects, federal health regulators said on Wednesday.

Regulators warned, however, that the data was limited and that they should rely on J & J’s own analysis for some of the study’s findings, rather than conducting their own.

Food and Drug Administration staff gave their assessment of the J&J recall data as part of the agency’s review of the company’s second dose authorization request.

After authorizing recalls for seniors and certain high-risk people who received Pfizer’s Covid-19 vaccine Inc.

and BioNTech SE, FDA Now Considering Removing Additional Doses From J&J and Moderna Injections Inc.

He also wonders if the doses could be mixed between different vaccines.

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The review of FDA staff is now in the hands of an external expert panel, which is due to meet on Friday to discuss J&J’s request to give the green light to a booster dose. The FDA is expected to make a decision after the panel meeting.

The panel will also examine data on mixing and pairing of vaccines. Preliminary results from a study by researchers at the National Institutes of Health, published by the online preprint server medRxiv, suggest that people who received the J&J vaccine would achieve a stronger immune response from a second dose of drugs. Pfizer or Moderna vaccines, rather than another J&J. dose.

An additional dose of the same vaccine as the primary series increased antibody levels four to 20 times, while mixing and pairing of primary vaccines and booster doses increased antibody levels six to 76 times.

The study of 458 subjects, which was not peer reviewed or published in a scientific journal, also suggested that people who received the same messenger RNA vaccines for their first two vaccines could receive another dose of the vaccine. Pfizer-BioNTech or Moderna and have a strong immune response.

Preliminary data indicates that all of the boosters induced immune responses, regardless of which vaccine was used for the primary immunization, the researchers said.

A spokesperson for J&J said the NIH study shows that its booster injection increases immune responses, regardless of a person’s primary vaccination.

The FDA has released its personnel assessment and other material on J & J’s recall request. In an analysis by J&J, a booster dose of his vaccine given six months after the original vaccine increased levels of neutralizing antibodies after the first dose, including against the Delta variant. But FDA staff said the data was based on only 17 study subjects and that there were other confounding factors that limited the agency’s ability to assess the data.

In its request, J&J recommends that a booster be given six months or more after the first, although it can be given as early as two months after the first.


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The FDA did not say in its report whether it thought a two- or six-month interval was better.

In another much larger study, two doses of J & J’s vaccine, given two months apart, were 75% effective against moderate to severe cases of Covid-19, FDA staff said.

Efficacy was highest in people 18 to 59, at 77.6%, compared to 66.2% for people 60 and older, FDA staff said.

“Although this is not independently confirmed by the FDA from the data sets, the data summaries suggest that there may be an advantage in a second dose given approximately two months after the primary dose, compared to the efficacy seen in the pivotal study “which tested only one dose of the vaccine, FDA staff said.

FDA staff said analysis of J&J data shows that the efficacy of J&J’s single-dose vaccine is lower than reported for Covid-19 messenger RNA vaccines from Pfizer and BioNTech and Moderna.

To date, 14 million people in the United States have received the J&J vaccine, the company said. Worldwide, 33.5 million doses have been administered, including in the United States

The Biden administration pushed the boosters in large part to counter any waning strength of the vaccines and the contagious Delta variant. But many health experts have said there is insufficient evidence to offer reminders for most people, beyond those with weakened immune systems due to their age or condition. health.

As the FDA prepares to make a decision on whether to authorize Pfizer’s Covid-19 vaccine for children ages 5 to 11, public health officials and pediatricians share their research with families to assure parents hesitant about the safety of the vaccine. Photo: John Locher / Associated Press

J & J’s vaccine is currently the only one for which no booster doses are currently permitted in the United States. People who are immunocompromised can currently receive Moderna boosters, while a much wider range of adults can get Pfizer boosters.

J&J said in its report to the FDA that its single-dose vaccine is 75% effective worldwide against severe and critical cases of Covid-19.

The company said protection against such cases does not decrease in the United States for at least six months. Still, he said he has observed a decrease in protection against moderate to severe cases of Covid-19 around the world due to the emergence of coronavirus variants outside of the United States.

J&J said a second dose could increase protection and potentially ward off variants of the virus. An analysis of a study of 31,300 people showed that giving a second dose about two months after the first dose was 100% effective against severe and critical Covid-19.

Separate studies have shown that waiting even longer between doses (up to six months) could increase immune responses beyond what the two-month interval could achieve.

The company said the need for a booster and the timing may vary by region depending on the behavior of the virus.

U.S. vaccinations with J & J’s single-dose vaccine were halted in April as health officials investigated rare cases of blood clotting accompanied by low platelet levels in some vaccinees. Vaccine use has resumed, and J&J and regulators have added warnings about the rare risk, known as thrombosis with thrombocytopenia syndrome, or TTS, to the vaccine product information.

J&J said as of August 24, it has seen five to six cases of TTS per million doses administered, based on reports from its Global Safety Database. J&J said the rate was around two cases of TTS per million using criteria issued by the Centers for Disease Control and Prevention.

The FDA cleared J & J’s vaccine for use in late February, based on a large international trial showing it was 66% effective in preventing symptomatic cases of Covid-19.

Write to Peter Loftus at and Felicia Schwartz at

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