And then there were three: a single-shot vaccine is the latest weapon to join the battle against COVID-19 in the United States.
On February 27, the U.S. Food and Drug Administration issued an emergency use authorization for Johnson & Johnson’s vaccine against SARS-CoV-2, the coronavirus that causes COVID-19. South Africa is the only other country to have vaccinated with OK Johnson & Johnson so far, although other countries are ready to follow suit.
The FDA has determined that the Johnson & Johnson vaccine meets safety and efficacy criteria and that there is clear evidence that it can prevent COVID-19, the agency said in a statement.
“With today’s authorization, we’ve added another vaccine to our medical toolbox to fight this virus,” said Peter Marks, director of the FDA’s Center for Biological Assessment and Research.
Its authorization for emergency use in the United States – for people 18 and older – follows similar authorizations in December for vaccines made by Moderna and Pfizer and its German partner BioNTech.
The shortage of vaccines makes the addition of a safe and effective third vaccine welcome. “We are still in the midst of this deadly pandemic,” says Archana Chatterjee, dean of the Chicago School of Medicine at Rosalind Franklin University of Medicine and Science.
“Authorization of this vaccine will help meet the needs at this time,” he said Feb. 26 after an FDA vaccine advisory committee voted unanimously to recommend the Johnson & Johnson vaccine for emergency use.
But even when the pharmaceutical company is willing to send 4 million doses, doubts remain about how well the public will adopt the new shot.
Sign up to receive email updates on the latest news and coronavirus research
On the one hand, people tired of struggling to establish not just one, but two appointments to receive the currently available double-dose vaccines can host a single window. And adding millions more vaccines to the pipeline should accelerate efforts to protect the vast majority of Americans.
But, on the other hand, their efficacy results are lower than those reported in two vaccines of mRNA vaccines performed by Moderna (94.1 percent) and Pfizer (95 percent) (SN: 29/1/21; SN : 16/11/20; SN: 18/11/20). In real-world situations, a single shot of the Pfizer vaccine was 74% to 85% effective in preventing hospitalizations (SN: 26/02/21).
In clinical trials, the Johnson & Johnson vaccine was approximately 66 percent effective in preventing moderate to severe disease. Its effectiveness rose to 85 percent when it came to preventing serious and critical cases that required hospitalization.
Here's what you need to know about the vaccine, developed by Johnson & Johnson's subsidiary, Janssen Pharmaceuticals:
How does it work?
The researchers developed a common cold virus called adenovirus 26 to carry instructions for making the coronavirus ear protein into human cells. Human cells make the viral protein, which causes the immune system to produce antibodies and train immune cells to attack the coronavirus, if the person encounters it later.
Engineering adenovirus 26, which has been modified so that it cannot cause disease, is the basis for other vaccines manufactured by Janssen, including an approved Ebola vaccine, and experimental vaccines against Zika, HIV, and respiratory syncytial virus (RSV). . Together, trials of these vaccines have tested the engineering virus on more than 193,000 people, including children, pregnant women and immunocompromised people. These tests have shown that the technology has a good safety record.
Why is it less effective than other authorized vaccines?
It may be unfair to directly compare effectiveness results. The Johnson & Johnson vaccine was tested in the United States, South Africa, Brazil, and other parts of Latin America when circulating variants of coronavirus that may escape some immune protection. Under the same conditions, mRNA vaccines may also be less effective.
This is also a one-shot vaccine. Its effectiveness is similar to that of a different two-dose adenovirus vaccine made by Oxford University and its partner AstraZeneca (SN: 23/11/20).
Johnson & Johnson began testing whether a second dose of their vaccine could increase effectiveness. If a second dose improves efficacy, researchers worry that the new information could sow confusion among those who have already received the shot.
"If you take a single-dose vaccine … and then you say a second dose is clinically better enough than we recommend a second dose, you can see how confusing that would be," said Paul Offit, director of the Children's Hospital Vaccine Education Center. Philadelphia said during the FDA's vaccine advisory board meeting.
Should I get shot?
Yes, experts say.
"We'll have to communicate effectively so people don't feel like they're getting a second-hand product. He's very good at what he does," says Georges Benjamin, executive director of the American Public Health Association in Washington, D.C.
Although the Johnson & Johnson vaccine did not prevent moderate or severe disease, as well as mRNA vaccines, "it will protect, no matter what, the part of the disease that really matters to us, which is hospitalization, serious illness, and death." , of Benjamin. "There's no difference."
See our full coverage of the coronavirus outbreak
As of Feb. 25, more than 52,000 people were hospitalized in the United States fighting COVID-19, according to the COVID monitoring project. This dropped from daily highs of more than 130,000 in early January and the lowest since early to mid-November. More than half a million people in the United States have now died from COVID-19.
In the Johnson & Johnson clinical trial, two of the 19,514 people in the vaccine group were hospitalized with COVID-19 from 14 days after vaccination. That compares with 29 hospitalizations among the 19,544 people in the placebo group. None of the vaccinated people died, but there were seven COVID-19-related deaths in the placebo group. Those numbers are small and some researchers say the data is unclear about the benefits.
“The data indicate that the vaccine is effective, but it does not show that the vaccine is especially effective against moderate to severe COVID,” said Diana Zuckerman, president of the National Center for Health Research, a Washington-DC-based think tank. . analyzes health research.
Data were also collected after only two months of follow-up. Typically, the FDA requires a year or more of data to fully approve a vaccine. Some questions about the vaccine cannot be answered with less than six months of data, Zuckerman said during a public comment period at the Feb. 26 advisory board hearing. “Let’s be very honest with the audience about what we know and what we won’t know” for a while.
For all vaccines, no one knows how long immunity will last. And what is already authorized may need to be modified if resistant variants are generalized. Reinforcement shots may be needed, Benjamin says.
Most people probably can't choose which vaccine they get, but if the choice is to take the Johnson & Johnson vaccine or wait months for an mRNA vaccine, "for me it's not an upcoming call. I should get the J&J now," he says. Robert Wachter, who chairs the Department of Medicine at the University of California, San Francisco. "The best vaccine is the one you get today."
How many people will be able to get the vaccine?
The company failed to meet its target of delivering 10 million doses by the end of February. But it may have 20 million doses by the end of March and 100 million by the end of June, a company official told a subcommittee of the U.S. House of Representatives Energy and Commerce Committee on Feb. 23.
Because the vaccine is given at once, each dose is enough to vaccinate a person. The Pfizer and Moderna vaccines require two shots for complete effectiveness.
“The fact that it’s a single dose lends itself to changing the game,” says Krishna Udayakumar, director of the Duke Global Health Institute in Durham, N.C.
People who are afraid of needles or those who cannot rest from work or have no transportation to vaccination sites may prefer a single shot over two-dose mRNA vaccines.
“We have poorly housed people coming to the emergency room,” Wachter says. “They don’t have a doctor. They have no home and are we going to try to vaccinate them and bring them back in a month? It’s just not going to work. ”A single-dose vaccine would be ideal in that context.
In addition, the vaccine does not require freezing. It can be stored in a standard refrigerator for up to three months. This facilitates its use in places that do not have easy access to the freezers needed to keep mRNA vaccines fresh.
With the three vaccines authorized, the United States may have enough doses in late summer to vaccinate everyone, Udayakumar says.
The sooner the United States can vaccinate vulnerable populations, the sooner it can begin sharing vaccines with low-income countries through the World Health Organization’s COVAX program (SN: 26/02/20).
“We still have 130 countries that have had zero vaccines,” Udayakumar says. "In the United States we buy more vaccine than we could use."
Sign up to receive the latest from Science News
Headlines and summaries of the latest Science News articles, delivered in your inbox