How the Johnson & Johnson Covid-19 vaccine works and why it is important

Here’s what’s known about how it works and how it will fit into the vaccine mix.

Johnson & Johnson’s single-shot vaccine Covid-19 has been shown to be 66% effective in preventing moderate to severe diseases in a global phase 3 trial, the company announced on Friday.

The vaccine is generally 85% effective in preventing hospitalization and death in all regions where it has been tested.

Its effectiveness against moderate and severe diseases varies from country to country: 72% in the USA, 66% in Latin America and 57% in South Africa. It was measured from a month after the shot.

In South Africa, 95% of the cases in the trial were due to a variant known as B.1.351, which is known to be more contagious and contains mutations that may make the virus less susceptible to the immune response against the antibody – including antibodies produced by vaccination.

Even those who received moderate cases of Covid-19 at trial tended to have a milder course and develop fewer symptoms, Drs. Mathai Mammen, Janssen’s global head of research and development, said.

From one month after the shot, all hospitalizations and deaths occurred in the placebo group.

How it works

The J&J vaccine is known as a non-repetitive viral vector vaccine, using a cold virus called adenovirus 26.

Scientists made this vaccine by ingesting and integrating a small amount of genetic material encoding a piece of the new coronavirus with an attenuated version of adenovirus 26. J&J scientists have modified this adenovirus so that it can enter cells enter, but it can not repeat and make people. sick.

AstraZeneca uses a similar platform, but the adenovirus comes from a chimpanzee.

The adenovirus carries the genetic material of the coronavirus into human cells, tricking them into making pieces of the coronavirus protein – the part it uses to attach to cells. The immune system then responds to these pieces of the coronavirus.

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“So you are not infected with the virus that can give you Covid-19 if you get this vaccine. It only has some harmful Covid virus proteins on its surface,” said Dr. William Schaffner, an internist and infectious disease, explains. specialist at Vanderbilt University’s Department of Health Policy. “So it’s actually a sheep in wolf’s clothing, and if your immune system sees it, it responds to it and creates protection against it and in the future against the real virus that causes Covid-19.”

The technology used in the Covid-19 vaccine worked in conjunction with the Ebola vaccine by Janssen.

How is it different from the other Covid-19 vaccines?

Dr Paul Offit, director of the Vaccine Education Center at Philadelphia Children’s Hospital, said the Moderna, Pfizer and J&J Covid-19 vaccines all follow the same path, but there is a slight difference with the J&J approach.

“In the case of the Moderna and Pfizer vaccine, you just give the gene in a lipid nanoparticle or a fat drop,” Offit said. “In the case of J&J, you give the gene into a virus that cannot reproduce on its own.”

The J&J vaccine is so far the only Covid-19 vaccine given in a single dose. Modern and Pfizer use two. Like those of Moderna, it can also be kept at regular cooling temperatures and does not need to be deep-frozen like Pfizer’s.

How does a single-dose survey affect deployment?

A single dose, it will be much easier to administer and will mean that more people can be vaccinated because no one has to set aside to give someone a second chance.

“This benefit is rising in neon,” said Schaffner, who believes the addition of a vaccine like this will “accelerate” vaccination efforts in the U.S. and around the world.

“If it’s a single-dose vaccine, a billion vaccine doses will be translated into a billion people being vaccinated,” said Dr. Dan Barouch of Harvard Medical School said. He helped develop Johnson & Johnson’s vaccination candidate on the Coronavirus Fact vs. CNN CNN Podcast.

The cold chain benefit

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& J’s other advantage is that it can be stored at regular refrigerator temperatures, unlike the Pfizer vaccine, which requires special freezers. The vaccine is stable for up to three months at 36 degrees F to 46 degrees F, the company said. This means that healthcare facilities do not have to buy extra equipment to store the vaccine safely.

“If successful, these vaccines will be especially popular in the developing world because they are easy to store and administer,” said Dr. Rafi Ahmed, the director of the vaccination center at Emory University, said.

The vaccines will also be popular in rural communities in the US and regular doctor’s offices that may not have access to the budget to afford special equipment.

“In other words, we can bring the vaccine to the people,” Schaffner said, “rather than bringing the people to the vaccine.”

What happens next?

The company will apply for FDA authorization, or an EUA, in early February.

The data will be examined more closely by the FDA and advisers from the US Centers for Disease Control and Prevention.

While the FDA reviews the data, it plans to hold a public meeting of the Advisory Committee on Vaccines and Related Biological Products. The committee is made up of independent scientific and public health experts who will discuss the J&J data and make a recommendation to the agency.

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Once an application was submitted, “The FDA really, very, very closely looks at the data in every age group and in every demographic group,” said dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a call Friday.

Following the meeting, FDA staff members will consider the input of the committee, along with evaluating the agency’s data from the company, and will decide whether the vaccine should be authorized.

Shortly after an EUA, the CDC’s Advisory Committee on Immunization Practices, also known as ACIP, also reviewed the data.

After the CDC committee has made a recommendation and it has been approved by the CDC director, the company plans to ship the vaccines immediately and can go into arms immediately.

How long does the authorization process take?

According to Offit, which is a member of the FDA’s VRBPAC, the process for the Johnson & Johnson vaccine should be about the same as for the Moderna and Pfizer vaccinations.

With the Pfizer vaccine, it has taken a little over three weeks since the company submitted its data to an EUA. With the Moderna vaccine, it took a little over two weeks.

If the vaccine is approved for emergency use, “our plan is to have the stock immediately after launch,” Moms said.

How many doses are there?

The US ordered 100 million doses and the company manufactured them while testing the vaccine. Usually companies wait to make the vaccine after it is approved, but that changed during the pandemic.

Johnson & Johnson says it could meet its 100 million dose commitment by June.

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