One Dose of J.&J. Vaccine Is Ineffective Towards Delta, Examine Suggests

The coronavirus vaccine made by Johnson & Johnson is way much less efficient in opposition to the Delta and Lambda variants than in opposition to the unique virus, in line with a brand new research posted on-line on Tuesday.

The findings add to proof that the 13 million folks inoculated with the J.&J. vaccine might must obtain a second dose — ideally of one of many mRNA vaccines made by Pfizer-BioNTech or Moderna, the authors stated.

However the conclusions are at odds with these from smaller research printed by Johnson & Johnson earlier this month suggesting {that a} single dose of the vaccine is efficient in opposition to the variant even eight months after inoculation.

The brand new research has not but been peer reviewed nor printed in a scientific journal, and relied on laboratory experiments. However it’s per observations {that a} single dose of the AstraZeneca vaccine — which has an identical structure to the J.&J. vaccine — exhibits solely about 33 {9408d2729c5b964773080eecb6473be8afcc4ab36ea87c4d1a5a2adbd81b758b} efficacy in opposition to symptomatic illness attributable to the Delta variant.

“The message that we wished to present was not that folks shouldn’t get the J.&J. vaccine, however we hope that sooner or later, it is going to be boosted with both one other dose of J.&J. or a lift with Pfizer or Moderna,” stated Nathaniel Landau, a virologist at N.Y.U.’s Grossman Faculty of Medication, who led the research.

Different consultants stated the outcomes are what they might have anticipated, as a result of all the vaccines appear to work higher when given in two doses. “I’ve at all times thought, and infrequently stated, that the J.&J. vaccine is a two-dose vaccine,” stated John Moore, a virologist at Weill Cornell Medication in New York.

Dr. Moore pointed to a number of research in monkeys and people that have shown greater efficacy with two doses of the J.&J. vaccine, compared with one dose. He said the new study was particularly credible because it was published by a team with no ties to any of the vaccine manufacturers.

But the data from the new study “do not speak to the full nature of immune protection,” said Seema Kumar, a spokeswoman for J.&J. Studies sponsored by the company indicate that the vaccine “generated strong, persistent activity against the rapidly spreading Delta variant,” she said.

The Delta variant is the most contagious version yet of the coronavirus. It accounts for 83 percent of infections in the United States, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said at a Senate hearing on Tuesday.

Dr. Landau’s team would probably have seen a similar increase in the vaccine’s potency if they had looked at the data over time, said Dr. Dan Barouch, a virologist at Beth Israel Deaconess Medical Center in Boston. The data on the J.&J. vaccine’s strength against the Delta variant at Day 29 is not much different from those reported in his own study, Dr. Barouch said.

“Fundamentally I don’t see that there’s any discordance,” he said. “The question is that of kinetics, it’s not just magnitude, because immune responses are not static over time.” The new study also did not consider other components of immune defense, he added.

Dr. Landau and his colleagues looked at blood samples taken from 17 people who had been immunized with two doses of an mRNA vaccine and 10 people with one dose of the J.&J. vaccine.

The J.&J. vaccine started out with a lower efficacy than the mRNA vaccines and showed a bigger drop in efficacy against the Delta and Lambda variants. “The lower baseline means that what’s left to counter Delta is very weak,” Dr. Moore said. “That is a substantial concern.”

Very few vaccines are given as a single dose, because the second dose is needed to amp up antibody levels, noted Akiko Iwasaki, an immunologist at Yale University. People who were inoculated with the J.&J. vaccine “are relying on that primary response to maintain high levels of antibodies, which is difficult, especially against the variants,” she said.

Boosting immunity with a second dose should raise the antibody levels high enough to counter the variants, she said.

Turning to an mRNA vaccine for the second shot, rather than another J.&J. shot, may be better: Several studies have shown that combining one dose of the AstraZeneca vaccine with a dose of the Pfizer-BioNTech or Moderna vaccines kicks up the immune response more effectively than two doses of AstraZeneca.

The Food and Drug Administration has said “Americans who have been fully vaccinated do not need a booster shot at this time,” and the agency is unlikely to change its recommendations based on laboratory studies. But the new data should prompt the F.D.A. to revisit its recommendations, Dr. Landau said: “I hope that they read our paper and think about it.”

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