Johnson & Johnson’s COVID-19 Vaccine Results Better Than They Look

Credit – U. Baumgarten via Getty Images – 2021 Ulrich Baumgarten

Johnson & Johnson pharmaceutical companies Janssen announced on January 29 that its COVID-19 one-shot vaccine is 66% effective in protecting against disease, but 85% effective against serious illness – results that could make it particularly effective. invaluable in the vaccination effort. regions of the world with weak health care systems.

By comparison, vaccines already licensed in the United States – one from Moderna and one from Pfizer-BioNTech – each require two doses, spaced three to four weeks apart. Janssen’s vaccine can also be stored in normal refrigerators, unlike Moderna and Pfizer-BioNTech, both of which must be frozen. While Moderna and Pfizer-BioNTech’s vaccines are around 94% to 95% effective in protecting against COVID-19, it is after two doses of these mRNA-based injections a relatively new vaccine platform. . Janssen’s vaccine takes a more traditional approach: it uses a harmless human cold virus to pass a gene for SARS-CoV-2 to the human immune system, which then learns how to protect the body against COVID-19. (SARS-CoV-2 is the virus that causes COVID-19.)

“A single dose vaccine is considered by the World Health Organization to be the best option in pandemic situations, improving access, distribution and compliance,” said Dr Paul Stoffels, Scientific Director of J&J, in a press release. “85% effectiveness in preventing serious illness from COVID-19 and preventing medical interventions related to COVID-19 will potentially protect hundreds of millions of people from serious and fatal outcomes of COVID-19.”

J&J’s results came days after Maryland-based Novavax reported that, in a Phase 3 trial, its vaccine was nearly 90 percent effective in protecting against COVID-19 disease. These results are all the more reassuring given that this study was carried out on 15,000 people in the United Kingdom, where a new mutant variant of SARS-CoV-2 is rapidly emerging. The high efficacy suggests that people vaccinated with the Novavax vaccine, which is based on another proven technology for injecting proteins made by SARS-CoV-2 to stimulate an immune response, can expect good protection against this. new variant.

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Dr Paul Goepfert, director of the Alabama Vaccine Research Clinic at the University of Alabama and principal investigator of the Janssen study, says he believes the effectiveness of the Janssen vaccine, in particular against emerging variant strains, justifies its use as soon as possible. , and potentially increase with an additional dose if studies support such a decision. Confronting a rapidly mutating virus requires vaccinating as many people as possible as quickly as possible, Goepfert said – a sentiment echoed by Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, in a briefing from the January 29. “Viruses cannot mutate if they cannot replicate themselves,” Fauci said. “So we have to keep doing what we’re doing, which is to increase our ability to vaccinate as many people as possible, as quickly as possible.”

The efficacy of Janssen’s vaccine, although lower than that of the Moderna and Pfizer-BioNTech versions, is probably still sufficient for authorization in most countries. Before studies on the first vaccines were completed, for example, the United States Food and Drug Administration set a minimum threshold of efficacy of 50 to 60% for considering vaccines for authorization. Moderna and Pfizer-BioNTech, the first two companies to report vaccine test results, have far exceeded that and set the bar high. But Goepfert says it’s not a fair comparison.

“We shouldn’t just watch [Janssen results] and say that it didn’t work out very well. That’s not the thing to remember here, ”says Goepfert. “The Moderna and Pfizer studies were done at a time when the virus hadn’t mutated much. And you have to remember that the effectiveness of Janssen is after one dose, compared to two doses of Moderna and Pfizer. “

In the Janssen study, which involved more than 43,000 people in eight countries – the United States, Argentina, Brazil, Chile, Colombia, Mexico, Peru and South Africa – the single shot was 66% effective in protecting against the disease Moderate to severe COVID-19. and 85% effective in specifically protecting against serious illness about one month after injection. Efficacy varies by country – in the United States, the study showed that the vaccine was 72% effective in protecting against moderate to severe COVID-19 disease, but 66% in Latin American countries and 57 % in South Africa.

These differences may reflect the rise of different mutant strains of SARS-CoV-2 around the world. In the study, most cases of the disease in South Africa, for example, were caused by the mutant virus, which scientists say is showing signs of resistance to already licensed vaccines. Janssen’s vaccine targets the spike protein that SARS-CoV-2 uses to bind to and infect human cells, and the variant circulating in South Africa has changed its genetic structure so that it binds in a way slightly different. This means that immune defenses like the antibodies generated by vaccines designed to block the original spike protein might not be as effective at blocking the variant.

Yet Janssen’s study shows that the immunity induced by the vaccine was sufficient to protect against COVID-19 disease, and perhaps more importantly, protect against death after infection. The study was conducted in collaboration with scientists from NIAID and the Biomedical Advanced Research and Development Authority of the US Department of Health and Human Services, and will continue to follow participants for two years. Goepfert says the company is also studying a two-dose regimen to see if it can further boost immune protection.

Testing already authorized COVID-19 vaccines, as well as future vaccines, against emerging mutations will be a priority for scientists and regulators. So far Moderna, Pfizer-BioNTech and Novavax report that tests with blood taken from people vaccinated with their injections show that they are able to neutralize the UK and South Africa variants, although that Moderna and Novavax found that recipients produced fewer antibodies against the South African. strain. Yet all studies show that the immune response generated by vaccines remains strong enough to protect against disease.

Staying on top of new mutations in the virus is a priority for the U.S. Centers for Disease Control and Prevention, agency director Dr. Rochelle Walensky said in the Jan. 29 briefing. The CDC is expanding its viral sequencing efforts by working with government, academic and commercial partners to collect more samples from COVID-19 patients and genetically sequence the virus they contain to monitor changes in viral genomes that could report imminent resistance to vaccines or drugs. “We’re asking for monitoring from each state, about 750 samples per week, and with collaborations with the university, we hope to do thousands per week,” she says.

Janssen plans to submit an emergency use authorization application in the United States and elsewhere. If allowed, it will be up to global health officials to decide whether the convenience of administering the single dose and its ability to be stored in refrigerated conditions is sufficient to justify the lower overall efficacy of Janssen’s vaccine.