JOhnson & Johnson said on Friday that his single-dose vaccine Covid-19 reduced rates of moderate and severe illness, but the injection appeared less effective in South Africa, where a new variant of the coronavirus has become common.
Overall, the vaccine was 66% effective in preventing moderate to severe illness 28 days after vaccination. But the effectiveness differs depending on the geography. The injection was 72% effective among clinical trial volunteers in the United States, but 66% among those in Latin America and only 57% among those in South Africa. Although markedly below the levels seen with the first two authorized Covid-19 vaccines , these rates are above the limits originally set by the U.S. Food and Drug Administration for a vaccine to be considered useful.
The vaccine reduced serious illness by itself by 85% and prevented Covid-related hospitalization or death, Johnson & Johnson said.
“In a pandemic, if you can, with a single dose vaccine, quickly eliminate the serious consequences of death, hospitalization and serious illnesses, this is what is important for society,” said Paul Stoffels, the company’s scientific director, to the STAT.
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Eric Topol, director and founder of the Scripps Research Translational Institute, considered the results “disappointing”, but added that a vaccine that prevents the most serious results, such as hospitalization and death, is still valuable. “This reinforces our luck that the first two are more effective,” he added.
The results started a new phase in the battle against the SARS-CoV-2 virus, which causes Covid-19. Different vaccines against the virus are proving to have varying levels of effectiveness, but also different attributes that can make them more – or less – valuable in certain contexts.
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The results of the first two authorized vaccines, one from partners Pfizer and BioNtech and the second from Moderna, were considerably stronger, reducing symptomatic infection by about 95%. But these vaccines require two doses. They also present distribution challenges, as they need to remain at ultra-low 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 to make vaccines less effective. Novavax, another vaccine manufacturer, said on Thursday that its vaccine was 90% effective in the UK, but only 49% effective in South Africa. The existence of such a variant raises the possibility that vaccine manufacturers will have to develop booster vaccines to protect against it. They may even need to do this regularly, as new strains of the coronavirus emerge.
The effectiveness of authorized vaccines appears to be somewhat diminished by strain B.1.351 in test tube experiments, but has not yet been tested against it in clinical research.
“The political implications of having different vaccines with different levels of effectiveness are huge,” said Carlos del Rio, a professor of infectious diseases at Emory University School of Medicine. “To deal with this pandemic and prevent it from spreading, I think you use all the tools in the toolbox.”
The results of J&J are from a provisional analysis of a study with 44,325 volunteers, in which 468 symptomatic cases of Covid-19 occurred. They are being revealed Friday morning at a news 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. As the study is still ongoing, the data may 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 these same virus proteins. Similar technology was used in the vaccine developed by Oxford University and AstraZeneca.
J&J said the trial did not result in any significant safety concerns about the vaccine. A case of stroke in a volunteer, which prompted researchers to pause the test this fall, was determined to be unrelated to the vaccine, said Stoffels. Fevers occurred in 9% of those who received the vaccine, and fevers of more than 104 degrees occurred in 0.2% of those who received the vaccine. Serious adverse events were more common among those who received placebo than the vaccine.
No matter the age of the volunteers in the study, the vaccine appeared to be highly effective, said Stoffels. There were concerns that its effectiveness might be less robust in older people.
Akiko Iwasaki, a virologist at Yale University, said the results of the Novavax and J&J vaccines were strong. She noted that it is difficult to compare the results of J&J with those of other studies, because the former counted cases of mild Covid-19, while the J&J study included only the most sick.
Despite this, Iwasaki emphasized the importance of simply vaccinating as many people as possible, because the current lack of immunity in the majority of the population and the high number of cases are giving the virus the opportunity to mutate more often.
“We have to give the first dose to as many people as possible,” said Iwasaki. “These variants, which are more transmissible and potentially even more lethal, are increasing. I think we are really fighting against time ”.
Kert Viele, a statistician at Berry Consultants, made a similar observation. Approving more vaccines and expanding the global supply could mean that communities achieve collective immunity, in which a sufficient number of people are inoculated against a pathogen to interrupt transmission chains. “If we can reduce global cases,” said Viele, “we will reduce the emergence rate of all these strains for the benefit of all, and therefore the need for such reformulations in the future.”
One hope is that the efficacy of the Johnson & Johnson vaccine may increase if administered in a two-dose regimen. Johnson & Johnson is conducting another large study, involving 30,000 patients, testing two doses of the vaccine administered 57 days apart. However, said Stoffels, waiting so long between doses will delay results. He expects the results of the two-dose study to be read in the summer or fall.
The population in the study was “diverse and broad,” said J&J. Patients came from the United States (44%), Central and South America (41%) and South Africa (15%). Women represented 45% of the study and men 55%. Among participants worldwide, 59% were white, 45% Hispanic or Latino, 13% were black, 6% were Asian and 1% were Native Americans. The volunteers had health problems, including obesity, type 2 diabetes, hypertension and HIV.
The J&J vaccine will be much easier to distribute than the mRNA vaccines made 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 kept between 36 degrees and 46 degrees Fahrenheit.
Johnson & Johnson expects to file with the FDA to obtain an emergency use authorization in early February and, assuming the vaccine is authorized, will have a product ready to be shipped immediately after approval. The company declined to give details of how much would be available, except to say it expects to meet all of its 2021 supply commitments.