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Johnson & Johnson said on Friday that its single-dose Covid-19 vaccine reduced rates of moderate and severe disease, but the shot appeared to be less effective in South Africa, where a new variant of the coronavirus has become common.
Overall, the vaccine was found to be 66% effective in preventing moderate to severe illness 28 days after vaccination. But the effectiveness differs depending on the geography. The shot was 72% effective in clinical trial volunteers in the United States, but 66% in those in Latin America and only 57% in those in South Africa. Although significantly lower than the levels seen with the first two authorized Covid-19 vaccines, these rates are above the thresholds initially set by the United States Food and Drug Administration for a vaccine to be considered useful.
The vaccine on its own reduced serious illness by 85% and prevented Covid-related hospitalization or death, Johnson & Johnson said.
“In a pandemic, if you can, with a single dose vaccine, very quickly eliminate the serious consequences of death, hospitalization and serious illness, that is what is important to society,” he told STAT Paul Stoffels, scientific director of the company.
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Eric Topol, director and founder of the Scripps Research Translational Institute, called the results “disappointing,” but added that a vaccine that prevents the most serious consequences, such as hospitalization and death, is still valuable. “It reinforces the luck we had that the first two were more effective,” he added.
The results triggered a new phase in the fight against the SARS-CoV-2 virus, responsible for Covid-19. Different vaccines against the virus are found to have varying levels of effectiveness, but also distinct attributes that might make them more – or less – useful in certain settings.
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The results of the first two licensed vaccines, one from Pfizer and BioNtech partners and a second from Moderna, were significantly stronger, reducing symptomatic infection by approximately 95%. But these vaccines require two doses. They also present distribution challenges as they have to stay at ultra-cold temperatures.
The new variant of the virus that was first identified in South Africa, B.1.351, throws another wrench into the equation. It seems that vaccines are less effective. Novavax, another vaccine maker, said on Thursday that its vaccine was 90% effective in the UK but only 49% in South Africa. The existence of such a variant raises the possibility that vaccine manufacturers will have to develop booster shots to protect against it. They might even need to do it regularly, as new strains of the coronavirus emerge.
The efficacy of authorized vaccines appears to be somewhat impaired by strain B.1.351 in test-tube experiments, but has not yet been tested against it in clinical research.
“The policy implications of having different vaccines with different levels of efficacy are enormous,” said Carlos del Rio, a professor of infectious diseases in the Emory University School of Medicine. “To deal with this pandemic and stop the spread, I think you are using all the tools in the toolbox.”
J&J’s results come from an interim analysis of a study of 44,325 volunteers in which 468 symptomatic cases of Covid-19 occurred. They were unveiled Friday morning at a press conference with the National Institutes of Health, which helped conduct the study as part of the U.S. vaccination effort, known as Operation Warp Speed. Since the study is still ongoing, the data could still change.
Unlike the Pfizer / BioNTech and Moderna vaccines, which are based on a new technology called mRNA that uses the body’s own cells to produce a key viral protein, the J&J vaccine uses a type of virus called adenovirus to deliver genes that produce the same. virus. protein. Similar technology was used in the vaccine developed by the University of Oxford and AstraZeneca.
J&J said the trial did not lead to significant safety concerns about the vaccine. A case of stroke in a volunteer, which prompted researchers to put the trial on hold this fall, was determined to be unrelated to the vaccine, Stoffels said. Fevers occurred in 9% of those who received the vaccine, and fevers over 104 degrees occurred in 0.2% of those vaccinated. Serious adverse events were more common in people who received a placebo than the vaccine.
Regardless of the age of the volunteers participating in the study, the vaccine appears to have high efficacy, Stoffels said. It was feared that its effectiveness was less robust in the elderly.
Akiko Iwasaki, a virologist at Yale University, said the results from the Novavax and J&J vaccines were strong. She noted that it’s difficult to compare J&J’s results to those of other trials, as previous trials counted cases of mild Covid-19 while the J&J study included only the sickest.
Regardless, Iwasaki stressed the importance of simply vaccinating as many people as possible, as the current lack of immunity of the majority of the population and the high number of cases give the virus the opportunity to mutate more often. .
“We need to get the first dose to as many people as possible,” said Iwasaki. “These more transmissible and potentially even deadlier variants are on the increase. I think we are really fighting against time.
Kert Viele, statistician at Berry Consultants, made a similar point. The approval of more vaccines and the expanding global supply could mean communities achieve herd immunity, in which enough people are vaccinated against a pathogen to stop chains of transmission. “If we can reduce global cases,” said Viele, “we will reduce the rate of emergence of all these strains for the benefit of all, and therefore the need for such reformulations in the future.”
It is hoped that the effectiveness of the Johnson & Johnson vaccine could increase if given as a two-dose schedule. Johnson & Johnson is conducting another large study, enrolling 30,000 patients, testing two doses of the vaccine given 57 days apart. However, Stoffels said, waiting that long between doses will slow results. He expects the two-dose study results to be read in the summer or fall.
The study population was “diverse and large,” J&J said. Patients were from the United States (44%), Central and South America (41%), and South Africa (15%). Women made up 45% of the study and men 55%. Of the participants worldwide, 59% were White, 45% Hispanic or Latinx, 13% were Black, 6% were Asian, and 1% were Native American. The volunteers had health issues including obesity, type 2 diabetes, high blood pressure and HIV.
The J&J vaccine will be much easier to distribute than the mRNA vaccines manufactured by Moderna and Pfizer / BioNTech. The vaccine will remain stable for two years at -4 degrees Fahrenheit, and will remain stable for up to three months if stored between 36 degrees and 46 degrees Fahrenheit.
Johnson & Johnson plans to file an emergency use authorization with the FDA in early February and, assuming the vaccine is cleared, will have a product ready to ship immediately after getting the green light. The company declined to give details on how much is available except to say that it expects to meet all of its supply commitments for 2021.
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