Johnson & Johnson’s coronavirus vaccine is still effective eight months after being vaccinated against the highly contagious Delta variant, the company reported Thursday – a result that should reassure the 11 million Americans who received the vaccination.

The vaccine showed a slight decrease in effectiveness against the variant compared to its effectiveness against the original virus, the company said. But the vaccine was more effective against the Delta variant than the beta variant, which was first identified in South Africa – the pattern was also seen with mRNA vaccines.

Antibodies stimulated by the vaccine get stronger over time, researchers also reported.

The results were described in a press release, and the company announced that both studies were submitted for online publication on Thursday. One of these studies was accepted for publication in a scientific journal. Both studies are small, and the researchers said they published the results early because of the great public interest.

“The coverage of the variants will be better than expected,” said Dr. Dan Barouch, a virologist at Beth Israel Deaconess Medical Center in Boston. “There was a lot of misinformation out there so we decided we had to get this public right away.”

The intense discourse about Delta’s threat has made even immunized people worry about whether they are protected. The variant first identified in India is much more transmissible than previous versions of the virus, and its global spread has resulted in new health restrictions from Ireland to Malaysia.

In the USA, the variant now accounts for every fourth new infection. Public health officials said the vaccines approved in the United States will work against all existing variants, but the data is primarily based on studies of the mRNA vaccines from Pfizer-BioNTech and Moderna.

That made some people who received the Johnson & Johnson vaccine ask, What about us?

The frustration built before the Delta variant appeared. For example, the guidelines from the Centers for Disease Control and Prevention that vaccinated people could do without masks in many indoor situations were mainly based on data for mRNA vaccines. And reports of an accumulation of infections among players on the Yankees baseball team that the J. & J. Shot did nothing to allay fears that the vaccine might be inferior to others.

Martha Young, 63, of Mountain View, California received the J. & J. shot on April 9th. It wasn’t their first choice, but it was offered. But since then she has said, “I’m very, very frustrated with the lack of information.”

She added, referring to the J. & J. “I felt like I didn’t count, like I was statistically insignificant because so few of us stand a chance that we don’t have to worry about us.”

Some people familiar with the J. & J. Vaccine complained that they felt cheated by experts who said the vaccines were all equally good. “I was surprised to see others make that claim,” said Natalie Dean, biostatistician at the University of Florida. “I did not like it. People don’t want to feel misled. “

However, other experts said the clinical trials should have shown that the J. & J. Vaccine was lower than that of the mRNA vaccines. “Of course, 72 percent is less than 95 or 94 percent,” says Florian Krammer, an immunologist at the Icahn School of Medicine on Mount Sinai in New York.

Part of the difficulty with comparing the vaccines is that they were all tested individually and with different measures of success. The Pfizer-BioNTech and Moderna studies were designed to capture symptomatic infections, while the J. & J. Study looked at the prevention of moderate to severe infections by the vaccine.

Still, it’s clear that all vaccines keep people out of the intensive care unit and morgue far more effectively than scientists could hope for, said Danny Altmann, an immunologist at Imperial College London.

Updated

July 6, 2021, 7:44 a.m. ET

“It’s like arguing whether you want a Ferrari or a Porsche that goes 250 or 180 mph on a road that is only allowed to drive 30 miles an hour,” he said.

However, there are differences: The J. & J. The vaccine can allow more so-called breakthrough infections – which occur in people who are fully vaccinated – with mild to no symptoms than the mRNA vaccines.

People with asymptomatic infections are very unlikely to spread the virus, but their diagnosis can become a problem when they’re caught by routine tests – as was the case with the Yankees cluster – and they have to go into quarantine, said John Moore, one Virologist at Weill Cornell Medicine in New York.

Information on the effectiveness of the J. & J. The vaccine was slow to market because it was launched later and its use has been suspended due to concerns about rare blood clots. Many medical centers and hospitals offered staff the mRNA vaccines early on and were able to conduct studies to evaluate these vaccines.

But blood samples from people who were tested with the J. & J. Vaccines are a comparatively rare commodity, said Dr. Krammer. “It’s not that nobody cares, or we’re hiding something because the vaccine isn’t good,” he said. “It’s more of an access problem.”

In the absence of data, some experts had suggested that the J. & J. Vaccination against the Delta variant probably performed about as well as the AstraZeneca vaccine, which is widely used in Europe. But this vaccine is given in two doses compared to J. & J’s single dose.

“The thing that I do at J. & J. is that their technology platform is essentially very, very similar – almost indistinguishable from AstraZeneca, ”said Dr. Altmann. “Should it really be a two-dose vaccine like everything else?”

The single dose offers benefits for those with limited access or who do not want two doses for other reasons. The J. & J. The vaccine also lasts longer in the refrigerator than the others and was a welcome option earlier in the pandemic when vaccines were scarce.

But after the advent of variants like Beta and Delta, which seem to bypass the immune system in part, the discussion about boosters for J. & J. Receiver intensified. One dose of the AstraZeneca vaccine is much less effective against variants than two doses, and experts feared that J. & J. Shot could be similar.

The new study addressed some of these concerns. The researchers followed the immune responses in volunteers 29 and 239 days after the first vaccination. Ten of the study participants received only one dose of the J. & J. Vaccine while 10 others received a second dose of the J. & J. Shot or an mRNA vaccine.

While blood antibody levels produced after immunization with Pfizer-BioNTech or Moderna decrease after an initial increase, antibodies – and immune cells – are released by the J. & J. Vaccine persisted at a high level, the researchers found. (However, other studies have shown that immune responses generated by mRNA vaccines are also likely to last for years.)

A second dose of the J. & J. Vaccine raised antibody levels even higher. An mRNA booster increased them even further, although the numbers in each group are too small to be statistically significant.

Eight months after the J. & J. Vaccination, the participants’ antibodies against the variants also appeared to be more effective than after a month. One participant who received a single dose became infected with the coronavirus.

A lack of information on the immune response to the J. & J. Vaccine had led a lot of people to speculate that they might need a second vaccination, a dose of an mRNA vaccine. But what the new evidence suggests is that people following the J. & J. Vaccine does not need a booster.

They also can’t get a legal one, “unless they play the system, unless they pretend they’re vaccine-naïve and get an mRNA vaccine and essentially lie,” said Dr. Moors. “And I certainly don’t recommend people do that.”