A group of expert advisors from the Food and Drug Administration (FDA) unanimously voted Friday afternoon to recommend the one-dose Covid-19 vaccine developed by Johnson & Johnson for an emergency approval. The next step is for the FDA to accept the recommendation, which could come this weekend to clear the way for distribution.
Earlier this week, the FDA released a briefing on the results of the Phase 3 clinical trials of the Johnson & Johnson vaccine, which included 40,000 participants in multiple countries, randomly divided into placebo and treatment groups.
The main finding: the vaccine was 100 percent effective at 28 days in preventing deaths and hospitalizations from Covid-19 among the clinical trial participants who received the treatment. (Two vaccine recipients were hospitalized two weeks after receiving the injection with Covid-19.)
The vaccine was also 66.1 percent effective in preventing symptomatic Covid-19 disease after four weeks with consistent results across all age groups. When investigating the blocking of severe and critical cases of Covid-19, the Johnson & Johnson vaccine was 85.4 percent effective.
Mathai Mammen, global director of research and development at Janssen Pharmaceutical Companies, said during a press conference last month that the vaccine also had "simple vanilla safety results" with the vast majority of recipients having no problems. Most of the symptoms reported were mild, including fatigue, arm pain, and fever.
The levels of effectiveness against severe to critical Covid-19 changed depending on where the vaccine was tested. In the US, it was 85.9 percent after four weeks, while in South Africa, where a variant of the coronavirus with worrying mutations that help escape vaccines has become widespread, its effectiveness against serious diseases was reduced to 81.7 percent .
Health officials say that while Johnson & Johnson's efficacy results are not as high as those of Moderna and Pfizer / BioNTech, the two vaccines that have already received emergency approval from the FDA, the new vaccine's performance is still excellent is.
"If this had happened without prior notice and implementation of a vaccine with a 94.95 percent effectiveness (vaccine), it would have been said that this was an absolutely spectacular result," said Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases , during last month's press conference. The vaccine was developed by Janssen Pharmaceuticals, a division of Johnson & Johnson based in Belgium, together with the Beth Israel Deaconess Medical Center in Boston.
But unlike the vaccines from Moderna and Pfizer / BioNTech, Johnson & Johnson doesn't need a booster shot to circumvent its competitors' two-dose problems. There is no need to track people for their second dose, which means more people can be vaccinated faster. The shots also don't require frozen storage, which means they're cheaper and slightly easier to distribute.
"It's a complete game changer," said Lawrence Gostin, professor of health law at Georgetown University. "It changes the equation completely."
The Johnson & Johnson vaccine differs in other ways as well. It uses an adenovirus vector to provide instructions on how to make the coronavirus spike protein, which is also less expensive to produce than the mRNA platform used for the other vaccines. (It's estimated to cost around $ 10 per vaccine dose – roughly half the cost of the Pfizer / BioNTech vaccine.)
Johnson & Johnson has promised enough vaccines for 20 million Americans by the end of March and 100 million Americans by the end of June, despite production problems. That would be a huge increase in the 65 million Covid-19 vaccine doses that have been given in the US to date.
Even with an overall potency lower than the other two vaccines in the US market, the Johnson & Johnson vaccine could become a major player. It is the vaccine that “can increase equity,” said Saad Omer, director of the Yale Institute for Global Health, “especially when used strategically in countries that are difficult to reach and where it is less than a double dose Timeline would be particularly challenging. "Johnson & Johnson expects to distribute a billion doses of its vaccine worldwide this year.
As amazing as it is to develop multiple effective Covid-19 vaccines in record time, it is now clear that technology alone will not save the day. An orchestra of supply chains, manufacturing, logistics, human resources, and public trust must harmonize to get billions of shots in the arms around the world and finally bring the pandemic to an end. And there are other hurdles to overcome: controlling the spread of variants that appear to jeopardize the effectiveness of all vaccines we offer.
What we learned about the safety and effectiveness of the Johnson & Johnson Covid-19 vaccine
Johnson & Johnson launched separate clinical trials testing both a single dose and a double dose to see how well these strategies provide long-term protection against Covid-19. The single dose The Phase 3 arm was the first to provide efficacy results.
But evidence that this vaccine might be safe and effective has been around for months. The company published some of its early Phase 1 and Phase 2 trial data in a preprint paper in September and the final version of the paper in the New England Journal of Medicine in January. The papers showed that the vaccine was well tolerated among participants and appeared to be very effective: at a dose after 29 days, the vaccine ensured that 90 percent of participants had enough antibodies to neutralize the virus. After 57 days, that number reached 100 percent.
"When I looked at this, I thought, wow, this Johnson & Johnson product is very powerful in terms of immunogenicity after the first dose," said Monica Gandhi, professor of global medicine at the University of California in San Francisco. "Pfizer and Moderna vaccines required two doses to achieve this level of (virus) neutralization."
Like Pfizer / BioNTech, Johnson & Johnson "didn't rush to phase 3 (trials)," said Hilda Bastian, a scientist who has followed the global vaccine race. Instead, several vaccine doses and candidates were initially tested to see which ones might perform best in humans, and clinical trials were then conducted.
The vaccine was also tested in nine countries – the world's largest international phase 3 study, with more than 60,000 participants – which means many ethnic groups were represented in the data, Bastian said. "As if all of these weren't enough, it's one of those that could be made in South Africa and elsewhere," as Johnson & Johnson has manufacturing capabilities around the world, even in countries affected by the pandemic has been serviced, vaccine stocks are badly affected, she added.
The day this vaccine is approved "will be a big day for the future of this pandemic (and) a ticket to more of the world out of this disease," said Nicholas Lusiani, senior adviser at Oxfam America.
How adenovirus vector vaccines work
Part of the appeal of this vaccine lies in the technology behind it. Adenoviruses are a family of viruses that can cause a number of diseases in humans, including the common cold. They are very efficient at getting their DNA into the nucleus. Scientists concluded that if they could cut out the correct sections of the genome of an adenovirus and insert another DNA code (in this case, for a fragment of the new coronavirus), they could have a powerful system to provide instructions to cells.
For decades, scientists have experimented with adenovirus vectors as a platform for gene therapy and the treatment of certain types of cancer, using the virus to modify or replace genes in host cells. More recently, researchers have seen some success using adenoviruses as vaccines. An adenovirus vector vaccine has already been developed for the Ebola virus.
In addition to Johnson & Johnson and AstraZeneca / Oxford, CanSino Biologics from China is also developing an adenovirus vector Covid-19 vaccine. The Russian vaccine Sputnik V Covid-19 also uses this platform.
To make one of these vaccines, the adenovirus is modified so that it cannot reproduce, but it contains instructions for making a component of a virus. In the case of Covid-19, most adenovirus vector vaccines code for the spike protein of SARS-CoV-2, the part the virus uses to start an infection.
Human cells then read the instructions from the adenovirus and begin making the spike protein. The immune system recognizes the spike proteins as a threat and begins to build up its defenses.
Because adenoviruses exist naturally, they tend to be more temperature stable than the synthetic lipid nanoparticles used to deliver the mRNA in the Moderna and Pfizer / BioNTech vaccines.
"The beauty of the adenovirus vector vaccines is that they are a little more tolerant of extended shelf life and storage conditions," said Angela Rasmussen, a virologist at Georgetown University. Adenovirus vector vaccines can be stored at refrigerator temperatures, while mRNA vaccines require freezers. Pfizer / BioNTech's vaccine requires temperatures of minus 80 degrees Celsius.
This helps reduce the cost and complexity of making, selling, and administering adenovirus vector vaccines compared to other platforms. And just having another vaccine on the market A big step forward is the manufacture of a large pharmaceutical company with its own production infrastructure. "The more doses of vaccine we can have, the better," said Rasmussen.
An Army National Guard specialist gives instructions at one of four mass vaccination sites opened by the Washington State Department of Health on Jan. 26.
Jason Redmond / AFP / Getty Images
The next challenge for Johnson & Johnson after the FDA gives the green light is to get cans for millions of guns.
But, given three vaccines that will eventually hit the market, should people advocate for a particular vaccine?
“Right now when people ask me what vaccine should I get? It's pretty easy to answer that question because it's the question that is being offered to you, ”said Paul Sax, Professor of Medicine at Harvard Medical School. Vaccine supplies are limited, transmission of the virus is high, and hospitals are almost full so few people can be selective about what to get.
As vaccine supplies stabilize, doctors and health authorities can optimize vaccine distribution after the vaccine supply has stabilized. "When the effectiveness (of a given vaccine) is less but still pretty good, there may be a scenario where one vaccine is recommended for low-risk populations and another is recommended for high-risk populations," Omer said.
While the Johnson & Johnson vaccine has some key advantages over its competitors, it could face some of the same distribution problems that other vaccines have encountered, such as: B. Government-hospital misunderstandings and production barriers.
Researchers say all manufacturers must also start working to get vaccines to the rest of the world. The new variants that have surfaced in the UK, Brazil and South Africa and discovered in other parts of the world are a reminder that the virus continues to evolve and that a partially vaccinated population could exert more selective pressures, accelerating these mutations. So vaccination needs to be quick and global – and the Johnson & Johnson vaccine can be a crucial tool for that.
"In the long term, we need to think about making vaccines fair to the world, and vaccines that are easier to distribute in terms of cold chain needs will be huge in that regard," said Rasmussen.
But even when these vaccines hit the market, there is still more to learn: How long does the protection against vaccines last, whether there are rare complications, whether they prevent both transmission and disease, and how well these vaccines work against the new variants . There are already some worrying signs of how these variants may be evading vaccines. Continuing clinical trials will be critical, Sax said.
"You know we have millions of people who have already received these vaccines, which is exciting," he added. "We are on our way."