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Johnson & Johnson JNJ -3.56%
reported that its single dose Covid-19 vaccine protected against Covid-19 in an advanced stage trial, while being generally safe and well tolerated. Here’s what we know and don’t know:
How effective is J & J’s vaccine?
It seems to be working well. The vaccine was 66% effective in an advanced-stage study with about 44,000 volunteers aged 18 and older, according to the company. This indicates that the shot is protecting adults from moderate to severe Covid-19, the disease caused by the coronavirus. When it focused specifically on preventing serious illness, the vaccine was even more effective, showing a rate of 85%. In comparison, an annual influenza vaccine is considered effective if it is 60% effective.
How does this compare to the effectiveness of Pfizer and Moderna injections?
Pfizer’s vaccine Inc.
and its partner BioNTech SE was 95% effective in preventing people from getting sick with Covid-19 in its late stage study, while the Moderna vaccine was 94.1% effective. J & J’s shot did not perform as well in his trial. However, it can be difficult to compare between trials. And the timing of the testing may have played a role, as J&J’s took place as new coronavirus variants emerged. The vaccines do not appear to work as well against the variant first identified in South Africa, in particular. J & J’s vaccine was 57% effective in South Africa, compared to 72% in the United States in the advanced stage trial. Several vaccines have performed better than health experts deem necessary to protect many people and provide the community immunity needed to move on to post-pandemic life.
When might the vaccine become available?
J&J says it expects in early February to ask the US Food and Drug Administration to authorize the use of its vaccine. If the FDA takes the same time it takes to review and clear the first two Covid-19 vaccines – around three weeks – it could make a decision later in February or early March. J&J did doses while testing his shot, so he might be ready to ship supplies quickly after getting the green light from regulators.
What are the side effects of J & J’s vaccine?
The most common symptoms after vaccination were fatigue, headache, muscle pain, and pain at the injection site in an early stage study. In the advanced stage study, J&J said a small percentage of subjects had a fever and there were no serious allergic reactions.
Which vaccine should I receive?
The first you can, say health officials. Individuals may not have much choice due to limited supply and the vaccination site only offers one of the vaccines. If you have a choice, there are some key differences that could guide your decision. J & J’s vaccine, although it appears to be less effective in studies, is given as a single dose, which may be a more practical option than the two doses required for the Pfizer and Moderna vaccines, given at three or four weeks of age. ‘interval. Only Pfizer vaccine is licensed for adolescents 16 and 17 years old, while Moderna is licensed for 18 years and older. J & J’s is also likely to be licensed for adults, as only people 18 and over have participated in the company’s large clinical trial.
How was J & J’s vaccine tested?
As of September, J&J recruited more than 44,000 adults in the United States and several other countries, including Brazil and South Africa, in a clinical trial. The subjects received a single dose of the vaccine or a placebo. The researchers counted how many people subsequently contracted moderate to severe Covid-19 from 14 days after vaccination, until a number of people became ill. The researchers then looked at whether there were fewer vaccinated people than unvaccinated people among the Covid-19 cases.
How does J & J’s vaccine work?
The vaccine uses a harmless type of virus called adenovirus, which can cause symptoms of the common cold. It is modified to contain the DNA of the so-called spike protein found on the surface of the novel coronavirus. Once injected, the adenovirus carries the payload of DNA into human cells. Once inside the cells, the DNA payload causes the production of the spike protein. This, in turn, triggers an immune response that can later defend against the real coronavirus if a vaccinated person is exposed to it.
How viral vector vaccines work
Companies like Johnson & Johnson and AstraZeneca are working on vaccines that rely on a different mechanism to confer immunity than traditional vaccines.
Traditional vaccines
1. In conventional vaccines, such as those against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This causes the immune system to produce specialized antibodies which are adapted to recognize the virus.
2. After vaccination, the antibodies remain in the body. If the patient later becomes infected with the virus, antibodies can identify it and help neutralize it.
Scientists have isolated the coronavirus genes responsible for producing these advanced proteins. Genes are spliced into weakened and harmless versions of other viruses.
Instead of using the whole virus to generate an immune response, these vaccines rely on the outer edge proteins of the coronavirus, which are what antibodies use to recognize the virus.
Weakened virus with
spike protein genes
When injected into a patient, the genetically engineered viruses enter healthy cells where they produce advanced coronavirus proteins.
The advanced proteins produced by the cells stimulate the immune system to mount a defense, just like with traditional vaccines.
Antibody response generated by the vaccine
1. In conventional vaccines, such as those against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This causes the immune system to produce specialized antibodies which are adapted to recognize the virus.
2. After vaccination, the antibodies remain in the body. If the patient later becomes infected with the virus, antibodies can identify it and help neutralize it.
Scientists have isolated the coronavirus genes responsible for producing these advanced proteins. Genes are spliced into weakened and harmless versions of other viruses.
Instead of using the whole virus to generate an immune response, these vaccines rely on the outer edge proteins of the coronavirus, which are what antibodies use to recognize the virus.
Weakened virus with
spike protein genes
When injected into a patient, the genetically modified viruses enter healthy cells where they produce advanced coronavirus proteins.
The advanced proteins produced by the cells stimulate the immune system to mount a defense, just like with traditional vaccines.
Antibody response generated by the vaccine
1. In conventional vaccines, such as those against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This causes the immune system to produce specialized antibodies which are adapted to recognize the virus.
2. After vaccination, the antibodies remain in the body. If the patient later becomes infected with the virus, antibodies can identify it and help neutralize it.
Scientists have isolated the coronavirus genes responsible for producing these advanced proteins. Genes are spliced into weakened and harmless versions of other viruses.
Instead of using the whole virus to generate an immune response, these vaccines rely on the outer tip proteins of the coronavirus, which are what antibodies use to recognize the virus.
Weakened virus with
spike protein genes
When injected into a patient, the genetically modified viruses enter healthy cells where they produce advanced coronavirus proteins.
The advanced proteins produced by the cells stimulate the immune system to mount a defense, just like with traditional vaccines.
Antibody response generated by the vaccine
1. In conventional vaccines, such as those against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This causes the immune system to produce specialized antibodies which are adapted to recognize the virus.
2. After vaccination, the antibodies remain in the body. If the patient later becomes infected with the virus, antibodies can identify it and help neutralize it.
Instead of using the whole virus to generate an immune response, these vaccines rely on the outer edge proteins of the coronavirus, which are what antibodies use to recognize the virus.
Scientists have isolated the coronavirus genes responsible for their production
peak protein. Genes are spliced into weakened and harmless versions of other viruses.
Weakened virus with
spike protein genes
When injected into a patient, the genetically modified viruses enter healthy cells where they produce advanced coronavirus proteins.
The advanced proteins produced by the cells stimulate the immune system to mount a defense, just like with traditional vaccines.
Antibody response generated by the vaccine
What don’t we know about J&J’s vaccine?
We do not know its safety and effectiveness in children, or in pregnant women, their fetuses or breastfed babies. We also don’t know how long the protection from the vaccine will last. The company is conducting a separate study to test whether adding a second dose improves its performance.
Does J & J’s vaccine protect against new strains of coronavirus?
The vaccine was less effective in South Africa and Latin America than in the United States. This could be a sign that the vaccine is less protective against strains circulating in these areas, although J&J is still conducting this analysis. Even at the lowest level of efficacy in South Africa and Latin America, health experts say, J & J’s vaccine works well. The company said it was working on a version of the vaccine targeting the South African variant.
Dr Anthony Fauci, senior medical adviser to President Biden, said current Covid-19 vaccines are still expected to be effective against newer variants of the virus and that the United States may approach a “degree of normalcy” by then fall if most of the country was vaccinated by summer. Photo: Al Drago / Zuma Press
Write to Peter Loftus at [email protected]
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