What’s different about this latest vaccine?
The Pfizer-BioNTech and Moderna vaccines are made using messenger RNA, a technology that gives instructions for making a harmless piece of what is called the “spike protein.” The spike protein is found on the surface of the virus that causes COVID-19. The proteins made with the mRNA instructions activate the immune system, teaching it to see the spike protein as foreign and develop antibodies to fight it.
The vaccine by Janssen Biotech, owned by Johnson & Johnson, uses a different approach for delivering the genetic instructions for creating the coronavirus spike protein. Its vaccine uses an inactivated virus, called an adenovirus, which is a common virus that can cause a range of diseases, such as colds and pinkeye.
While the use of weakened or killed viruses for vaccines is not new, there haven’t been other adenovirus vaccines approved by public health authorities for people. But clinical trials are underway for adenovirus-based vaccines for HIV, Ebola, Zika and malaria, among other diseases.
What are the advantages of this new vaccine?
The vaccine requires only a single dose, rather than the two doses required for the mRNA vaccines, and it can become protective as early as 14 days after administration. The vaccine also can be stored in refrigerators for at least three months, the company says, while the new mRNA vaccines require much colder storage. Those advantages make it easier to distribute the vaccine in rural areas and administer it to masses of people during the pandemic.
How effective is it?
A review by the Food and Drug Administration found that the vaccine is highly effective at preventing hospitalizations and deaths 28 days after immunization.
Studies conducted in the U.S., South Africa and Central and South America showed it to be less effective, though, than the mRNA vaccines at preventing moderate illness, with an efficacy rate of 66% overall. That’s likely due, at least in part, to a decrease in effectiveness against the variant first found in South Africa.
The company’s trial showed it 72% effective in the U.S. against moderate to severe COVID.
Studies showed the vaccine protection was generally consistent across race and age groups, the company says.
Is it safe?
The FDA found no specific safety concerns with the vaccine.
Among the study participants, the most common side effects were soreness at the injection site, headaches, fatigue and muscle pain. Those were generally mild to moderate and more common in those ages 18 to 59 than to older participants in the trials.
Emergency use authorization of the vaccine means that the FDA considers that the benefits from the vaccine outweigh any risks.
Two people suffered severe allergic reactions shortly after getting the Johnson & Johnson COVID-19 vaccine, a J&J scientist told the FDA panel Friday. One of the people was participating in an ongoing trial in South Africa and developed anaphylaxis, a severe and potentially life-threatening allergic reaction, after getting the vaccine.
There were previously no reports of anaphylaxis in J&J’s clinical trial.
Severe reactions from the COVID-19 vaccines are considered extremely rare and the Centers for Disease Control and Prevention is monitoring them. All of the patients who experienced an allergic reaction were treated and recovered.
Should people consider waiting for the Pfizer-BioNTech or Moderna vaccines, which have higher efficacy?
No, don’t wait, experts say. They urge people to take whichever vaccine is available to them and focus on why it’s important to get the vaccine in the first place — to avoid hospitalization and death. Experts emphasize the results from the Johnson & Johnson’s clinical trials have shown the vaccine to be 100% effective at preventing hospitalizations and deaths.
Waiting for a preferred vaccine would slow down efforts to vaccinate people, leaving more at risk for severe illness from COVID-19.
However, those who have had serious allergic reactions to other vaccines should consult with their physician. The CDC advises that those with a severe allergic reaction to any ingredient in the Pfizer-BioNTech or Moderna vaccines not get them.
How many doses will J&J supply and when will they be available?
The company says it will have 4 million doses available to ship immediately as soon as the vaccine is authorized, although earlier it had pledged to have 10 million available by the end of February. Company officials now say they can have 20 million doses available to the U.S. government by the end of March. The U.S. has agreed to buy 100 million doses of the vaccine by June.
Federal officials said the vaccine will be distributed similar to the current allocation process.
The J&J vaccine could arrive as early as next week. Gov. Brian Kemp said he expects the state will receive 83,000 doses in the first week.
Who can get the vaccine?
Authorization was granted for adults 18 and older. No COVID-19 vaccines have been authorized yet for young children. However, the Pfizer-BioNTech vaccine is available for those ages 16 and 17.
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