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While Pfizer and Moderna both have COVID-19 vaccines licensed for emergency use in the United States, other vaccine candidates are still under development, including a single-dose option from Johnson & Johnson, which has approximately 45,000 people enrolled in ongoing Phase 3 clinical trials. . According to the first data just published by the company, this vaccine is also very promising.
Interim data for phase 1 / 2a were published on January 13 in the New England Journal of Medicine, and the results show that the company’s vaccine candidate has created an immune response in patients for at least 71 days – the total time measured in the study so far.
The vaccine was also “generally well tolerated” in study participants, Johnson & Johnson said in a press release. Although the Pfizer and Moderna vaccines are similar, Johnson & Johnson’s vaccine also has many differences. Here’s what we know so far and what lies ahead.
How does the Johnson & Johnson COVID-19 vaccine work?
Johnson & Johnson has an andenovector vaccine, which uses double stranded DNA to promote an immune response in the body. This technology works differently from mRNA vaccines available from Pfizer-BioNTech and Moderna, which both use single stranded RNA.
In the Johnson & Johnson vaccine, researchers added a piece of genetic material from the novel coronavirus spike protein (the piece that locks onto human cells) in another virus, adenovirus 26, which has been modified to that it can enter cells but not reproduce inside them. Adenoviruses are common viruses that usually cause cold-like symptoms, but because the one used in the vaccine has been altered and cannot replicate, it cannot make you sick. (Other COVID-19 vaccines, including the candidate from Oxford and AstraZeneca, use similar adenovirus technology.)
When you receive the Johnson & Johnson vaccine, the modified adenovirus carrying a piece of the spike protein locks onto the surface of your cells. It is sucked inside, where the modified virus travels to the cell nucleus, where its DNA is located. The adenovirus then places its DNA in the nucleus, the spike protein gene is read by the cell, and then it is copied into messenger RNA (mRNA).
After that, the mRNA leaves the nucleus and serves as an instruction set for other cells, so that they begin to make advanced proteins. These are then recognized by your immune system and your body responds by producing antibodies against the perceived threat (even if no threat exists).
Your immune system cells then remember how to fight off the distinct fragment of SARS-CoV-2, the new coronavirus, so if you come into contact with it in the future, your body will have the ability to fight it more effectively.
This technology is unique but Johnson & Johnson has a lot of experience with it, as it has already been used for their Ebola vaccine. “They gave hundreds of thousands of doses of this similar vaccine,” which had no major safety concerns, says William Schaffner, MD, infectious disease specialist and professor in the Vanderbilt University School of Medicine .
While still being tested, Johnson & Johnson’s COVID-19 vaccine may only require a turned rather than two. His trials so far have shown that administering one or two doses of the vaccine stimulated an effective immune response against SARS-CoV-2 in study participants, but nothing is set in stone until that the phase 3 clinical trials have been completed and the company has sufficient data. to support its single dose.
How effective is the Johnson & Johnson COVID-19 vaccine?
It’s not entirely clear at this point. Published data from preliminary trials found that over 90% of people vaccinated developed neutralizing antibodies (which should prevent SARS-CoV-2 from infecting your cells) 29 days after receiving the first dose of the vaccine. Two months after the first dose, all participants had developed neutralizing antibodies, which remained in place for at least 71 days.
What are the side effects of Johnson & Johnson COVID-19 vaccine?
According to data to date, it can cause “mild to moderate side effects usually associated with vaccinations”, similar to those expected from Pfizer and Moderna vaccines. This includes cold-like symptoms, such as a headache, body aches, pain at the injection site, and fever – a normal sign that the body’s immune response is underway.
How is the Johnson & Johnson COVID-19 vaccine stored?
One of the biggest advantages of the Johnson & Johnson vaccine is its durability. Because it does not contain delicate mRNA like the Pfizer and Moderna vaccines (which must be kept frozen), it is much less fragile and can remain stable in a normal refrigerator (36-46 ° F) for up to three months.
“That’s a big plus,” says Thomas Russo, MD, professor and chief of infectious diseases at the University of Buffalo in New York City. Safely storing other available vaccines, especially the Pfizer vaccine (which should be stored at a freezing temperature of -94 ° F) presents challenges for the average doctor’s office or pharmacy, as most places do not have specialized freezers that reach these temperatures.
When will it get emergency use clearance from the FDA?
“It’s too early to tell because we don’t have any Phase 3 clinical data yet,” says infectious disease expert Amesh A. Adalja, MD, principal investigator at the Johns Hopkins Center for Health Security.
However, he is hopeful, as “the results of the phase 2 clinical trial appear strong”. Dr Russo agrees that “at the moment there are no major issues with the safety signals.
Johnson & Johnson’s Phase 3 clinical trial is scheduled to end in mid-February. If all goes well, the company can apply for emergency use authorization from the Food and Drug Administration (FDA), explains Dr. Russo. Once the FDA gives its approval, it is possible that the vaccine will be authorized in March.
In August, the company signed a billion-dollar contract with the federal government, committing to produce 12 million doses of its vaccine by February and 100 million doses by the end of June. however, The New York Times production of reports can be delayed by about two months.
Will you have a choice of which COVID-19 vaccine you will receive?
At this point, it doesn’t seem likely. “In this initial phase of vaccination, there probably won’t be a lot of choice for people,” says Dr Adalja. Rather, it is the health department or agency that administers the vaccine that will make the decision, mainly depending on which vaccine is readily available in a specific area.
But a lot of it depends on what the data will say. “How effective is this vaccine exactly?” Says Dr. Schaffner. “If there is a noticeable difference, it could make a difference.”
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