The coronavirus vaccine manufactured by Johnson & Johnson is much less effective against the Delta and Lambda variants than against the original virus, according to a new study published online on Tuesday.
The results show that the 13 million people who used the J. & J. The vaccine may need to be given a second dose – ideally one of the Pfizer-BioNTech or Moderna mRNA vaccines, the authors said.
However, the conclusions contradict those from smaller studies published earlier this month by Johnson & Johnson, which suggest that a single dose of the vaccine is effective against the variant even eight months after being vaccinated.
The new study had not yet been peer-reviewed or published in a scientific journal and was based on laboratory experiments. However, it is consistent with observations that a single dose of the AstraZeneca vaccine – which has a similar architecture to the J. & J. Vaccine – only shows about 33 percent effectiveness against symptomatic diseases caused by the Delta variant.
“The message we wanted to get across wasn’t that people were making the J. & J. Vaccine, but we hope it will be reinforced with in the future either another dose of J. & J. or a boost with Pfizer or Moderna, ”said Nathaniel Landau, a virologist at NYU’s Grossman School of Medicine who led the study.
Other experts said the results are what they expected as all vaccines seem to work better when given in two doses. “I have always thought and often said that J. & J. Vaccine is a two-dose vaccine, ”said John Moore, a virologist at Weill Cornell Medicine in New York.
Dr. Moore pointed to several studies in monkeys and humans that showed greater effectiveness with two doses of the J. & J. Vaccine compared to a 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 “doesn’t speak about the whole nature of immune protection,” said Seema Kumar, a spokeswoman for J. & J. Company-sponsored studies suggest that the vaccine “produces strong, sustained activity against the rapidly spreading Delta variant,” she said.
The delta variant is the most contagious version of the coronavirus to date. It accounts for 83 percent of infections in the United States, said Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, at a Senate hearing on Tuesday.
The variant could also be responsible for a recent surge in infections: although they’re still low compared to last winter, cases are increasing in all 50 states and hospital admissions are increasing in almost all. In the two weeks ended Tuesday, there were an average of 268 deaths per day in the nation.
Delta can cause more breakthrough infections than previous forms of the virus, but more than 99 percent of hospitalizations and deaths occur in unvaccinated people. The vaccination rates in the country have stalled, almost 60 percent of adults are fully protected against the virus.
Several studies have shown that Pfizer-BioNTech and Moderna’s mRNA vaccines retain their effectiveness against the coronavirus, including all variants identified so far. For example, a recent study showed that the vaccines trigger a sustained immune response in the body that can protect against the coronavirus for years.
Updated
July 20, 2021, 4:10 p.m. ET
But evidence for the J. & J. The vaccine was limited as it was introduced later than the mRNA vaccines. Most of the studies on the effectiveness of the coronavirus vaccines were conducted in medical centers and hospitals, based on samples from staff who had received the mRNA vaccines.
The J. & J. The vaccine has also been followed by reports of blood clots and a rare neurological syndrome, as well as contamination problems at a Baltimore manufacturing facility.
Small studies published by researchers associated with J. & J. suggested that the vaccine against the Delta variant was only slightly less effective than against the original virus and that the antibodies stimulated by the vaccine grew in strength within eight months.
Dr. Landau would likely have seen a similar increase in the vaccine’s effectiveness if they looked at the data over time, said Dr. Dan Barouch, a virologist at Beth Israel Deaconess Medical Center in Boston. The data for the J. & J. The strength of the vaccine against the Delta variant on day 29 is not much different from what was reported in his own study, said Dr. Barouch.
“Basically, I don’t see any discrepancies,” he said. “The question is that of kinetics, it’s not just size, because immune responses are not static over time.” The new study does not consider other components of the immune system either, he added.
Dr. Landau and colleagues examined blood samples from 17 people who received two doses of an mRNA vaccine and 10 people who received one dose of the J. & J. Vaccination.
The J. & J. Vaccine started with less potency than the mRNA vaccines and showed a greater potency drop against the Delta and Lambda variants. “The lower baseline means that what is left against Delta is very weak,” said Dr. Moors. “That is a major concern.”
Very few vaccines are given as a single dose because the second dose is needed to raise antibody levels, noted Akiko Iwasaki, an immunologist at Yale University. Persons familiar with the J. & J. Vaccines “rely on this primary response to maintain high levels of antibody, which is particularly difficult against the variants,” she said.
Boosting immunity with a second dose should raise antibody levels high enough to counter the variants, she said.
For the second shot, let’s turn to an mRNA vaccine rather than another J. & J. Shot, Possibly Better: Several studies have shown that combining a dose of the AstraZeneca vaccine with a dose of the Pfizer BioNTech or Moderna vaccine is more effective than two doses of AstraZeneca.
The Food and Drug Administration has said, “Americans who have been fully vaccinated don’t need a booster right now,” and the agency is unlikely to change its recommendations based on laboratory studies. But the new data should cause the FDA to reconsider its recommendations, said Dr. Landau: “I hope you read our paper and think about it.”
