According to a study, J. & J. beneficiaries could be further helped by the booster of other brands

People who have received a vaccine against the Johnson & Johnson coronavirus may be better off with a booster from Moderna or Pfizer-BioNTech, according to preliminary data from a federal clinical trial released on Wednesday.

This finding, along with a mixed review by the Food and Drug Administration of the case presented by Johnson & Johnson for authorization of its recall, could lead to a heated debate over how and when to offer additional injections to the 15 million. Americans who received the single dose vaccine.

The agency’s panel of vaccine advisers will meet on Thursday and Friday to vote on whether to recommend that the agency allow Moderna and Johnson & Johnson to offer booster shots.

Despite questions raised by new data on the potency of Johnson & Johnson’s boosters, some experts predicted that the agency would wipe out injections anyway, as the efficacy of the single-shot vaccine is lower than that of two-shot mRNA vaccines. doses manufactured. by Moderna and Pfizer-BioNTech. And the general public can expect clearances too, given the pressure from the Biden administration for boosters of all brands.

After the agency cleared a recall from Pfizer-BioNTech last month, “the die was cast,” said John Moore, virologist at Weill Cornell Medicine.

The Pfizer and Moderna vaccines are by far the most widely used in the United States, with more than 170 million people in the United States fully immunized with either vaccine. When Johnson & Johnson’s was cleared in February, public health experts were eager to roll out the ‘one-and-done’ option, especially in communities with limited access to healthcare. But the shot’s popularity fell when the FDA subsequently suspended its use to investigate rare cases of blood clotting.

For those who have received the Johnson & Johnson vaccine, the timing of a recall authorization – of any brand – is still uncertain. The FDA panel is only due to vote on Friday on whether the agency should allow a second dose of the Johnson & Johnson vaccine, a scenario the Centers for Disease Control and Prevention’s vaccine advisory committee will discuss next week. If both agencies think an extra dose should be offered, people could look for it as early as next week.

Whether and how the FDA can authorize the mix-and-match approach is unclear. The strategy will be discussed at the agency’s panel meeting on Friday, but no votes will be taken. If regulators come to believe that there is sufficient scientific support for the approach, they would likely need to update the authorization language for Moderna and Pfizer-BioNTech vaccines to allow their use in people who initially received Johnson & # 39; s vaccine. Johnson.

In a study conducted by the National Institutes of Health, researchers organized nine groups of about 50 people each. Each group received one of three authorized vaccines, followed by a booster. In three groups, volunteers received the same vaccine for a booster. In the other six, they switched to another brand.

The researchers found that those who received an injection of Johnson & Johnson followed by a Moderna booster saw their antibody levels increase 76-fold in 15 days, while those who received another dose of Johnson & Johnson did ‘saw their antibody level only four-fold during the same period. A Pfizer-BioNTech booster injection increased antibody levels 35-fold in Johnson & Johnson recipients.

The authors cautioned against the small size of the study and noted that they did not follow the volunteers long enough to identify rare side effects.

Sharon LaFraniere contributed reporting from Washington.