J.&J. Vaccine May Be Less Effective Against Delta, Study Suggests - The New York Times

The coronavirus vaccine made by Johnson & Johnson is much less effective against the Delta and Lambda variants than against the original virus, according to a new study posted online on Tuesday.

vaccine may need to receive a second dose — ideally of one of the mRNA vaccines made by Pfizer-BioNTech or Moderna, the authors said.

The conclusions are at odds with those from smaller studies published by Johnson & Johnson earlier this month suggesting that a single dose of the vaccine is effective against the variant even eight months after inoculation.

But it is consistent with observations that a single dose of the AstraZeneca vaccine — which has a similar architecture to the J.&J.

vaccine — shows only about 33 percent efficacy against symptomatic disease caused by the Delta variant.

vaccine, but we hope that in the future, it will be boosted with either another dose of 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.

suggested that the vaccine was only slightly less effective against the Delta variant than against the original virus, and that antibodies stimulated by the vaccine grew in strength over eight months.

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 started out with a lower efficacy than the mRNA vaccines and showed a bigger drop in efficacy against the Delta and Lambda variants.

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.