Johnson & Johnson JNJ -3.56%
reported that their single dose vaccine Covid-19 protected against Covid-19 in a final stage test, although it was generally safe and well tolerated. Here’s what we know and don’t know:
How effective is the J&J vaccine?
It seems to work well. The vaccine was 66% effective in a final-stage study of about 44,000 volunteers aged 18 or older, according to the company. This indicates that the injection protects adults from Covid-19 moderate to severe, the disease caused by the coronavirus. By focusing specifically on the prevention of serious diseases, the vaccine was even more effective, with a rate of 85%. In comparison, an annual flu vaccine works well if it is 60% effective.
How does this compare to the effectiveness of Pfizer and Moderna photos?
The Pfizer vaccine Inc.
and the partner BioNTech SE was 95% effective in preventing diseases with Covid-19 in its final stage study, while the Moderna vaccine was 94.1% effective. J&J’s shot didn’t work so well in his trial. However, it can be difficult to compare tests. And the timing of the test may have played a role, as J&Js occurred as new variants of the coronavirus emerged. Vaccines do not seem to work as well against the variant first identified in South Africa, in particular. The J&J vaccine was 57% effective in South Africa compared to 72% in the United States during the final stage test. Several vaccines have outperformed what health experts say is needed to protect many people and provide the community immunity needed to move on to post-pandemic life.
When will the vaccine be available?
J&J says it expects, in early February, to ask the United States Food and Drug Administration to authorize the use of its vaccine. If the FDA took the same time it took to review and authorize the first two Covid-19 vaccines – about three weeks – it could make a decision in late February or early March. J&J has been taking doses while testing your injection, so you can be ready to ship supplies quickly after obtaining authorization from regulators.
What are the side effects of the J&J 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 final stage study, J&J said that a small percentage of participants had a fever and there were no serious allergic reactions.
Which vaccine should I get?
The first you can, say health officials. Individuals may not have much of a choice due to limited supplies and the vaccination site may offer only one vaccine. If you have a choice, there are some important differences that can guide your decision. The J&J vaccine, although it seems less effective in studies, is administered in a single dose, which may be a more convenient option than the two doses required for the Pfizer and Moderna vaccines, administered three or four weeks apart. Only the Pfizer vaccine is authorized for teenagers aged 16 and 17, while Moderna is released for those over 18. J&J will also likely be released for adults because only people aged 18 and over participated in the company’s large clinical trial.
How was the J&J vaccine tested?
As of September, J&J enrolled 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 fell ill. The researchers then examined whether there were fewer vaccinated than unvaccinated people among Covid-19 cases.
How does the J&J vaccine work?
The vaccine uses a harmless type of virus, called adenovirus, which can cause cold symptoms. It is modified to contain the DNA of the so-called spike protein found on the surface of the new coronavirus. Once injected, the adenovirus carries the DNA payload to 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 for conferring immunity than traditional vaccines.
Traditional Vaccines
1. In classic vaccines, such as against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This activates the immune system to produce specialized antibodies that are adapted to recognize the virus.
2. After vaccination, antibodies remain in the body. If the patient is later infected with the real virus, the antibodies can identify him and help neutralize him.
The scientists isolated the coronavirus genes responsible for producing these peak proteins. The genes are combined into weakened and harmless versions of other viruses.
Instead of using the entire virus to generate an immune response, these vaccines rely on the coronavirus’s external peak proteins, which are used by antibodies to recognize the virus.
Virus weakened with
peak protein genes
When injected into a patient, the genetically modified viruses enter healthy cells, where they produce peak coronavirus proteins.
The peak proteins produced by the cells stimulate the immune system to mount a defense, just as with traditional vaccines.
Antibody response generated by vaccine
1. In classic vaccines, such as against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This activates the immune system to produce specialized antibodies that are adapted to recognize the virus.
2. After vaccination, antibodies remain in the body. If the patient is later infected with the real virus, the antibodies can identify him and help neutralize him.
The scientists isolated the coronavirus genes responsible for producing these peak proteins. The genes are combined into weakened and harmless versions of other viruses.
Instead of using the entire virus to generate an immune response, these vaccines rely on the coronavirus’s external peak proteins, which are used by antibodies to recognize the virus.
Virus weakened with
peak protein genes
When injected into a patient, the genetically modified viruses enter healthy cells, where they produce coronavirus peak proteins.
The peak proteins produced by the cells stimulate the immune system to mount a defense, just as with traditional vaccines.
Antibody response generated by vaccine
1. In classic vaccines, such as against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This activates the immune system to produce specialized antibodies that are adapted to recognize the virus.
2. After vaccination, antibodies remain in the body. If the patient is later infected with the real virus, the antibodies can identify him and help neutralize him.
The scientists isolated the coronavirus genes responsible for producing these peak proteins. The genes are combined into weakened and harmless versions of other viruses.
Instead of using the entire virus to generate an immune response, these vaccines rely on the coronavirus’s external peak proteins, which are used by antibodies to recognize the virus.
Virus weakened with
peak protein genes
When injected into a patient, the genetically modified viruses enter healthy cells, where they produce peak coronavirus proteins.
The peak proteins produced by the cells stimulate the immune system to mount a defense, just as with traditional vaccines.
Antibody response generated by vaccine
1. In classic vaccines, such as against measles and polio, the patient is inoculated with weakened or inactivated versions of the virus. This activates the immune system to produce specialized antibodies that are adapted to recognize the virus.
2. After vaccination, antibodies remain in the body. If the patient is later infected with the real virus, the antibodies can identify him and help neutralize him.
Instead of using the entire virus to generate an immune response, these vaccines rely on the coronavirus’s external peak proteins, which are used by antibodies to recognize the virus.
Scientists have isolated the coronavirus genes responsible for producing these
peak proteins. The genes are combined into weakened and harmless versions of other viruses.
Virus weakened with
peak protein genes
When injected into a patient, the genetically modified viruses enter healthy cells, where they produce coronavirus peak proteins.
The peak proteins produced by the cells stimulate the immune system to mount a defense, just as with traditional vaccines.
Antibody response generated by vaccine
What do we not know about the J&J vaccine?
We do not know its safety and effectiveness in children or among pregnant women, their fetuses or breastfeeding babies. We also don’t know how long the vaccine will last. The company is conducting a separate study to test whether adding a second dose improves its performance.
Does the J&J vaccine protect against new strains of coronavirus?
The vaccine was less effective in South Africa and Latin America than in the United States. This may be a sign that the vaccine is less protective against the strains that circulate in these regions, although J&J is still conducting this analysis. Even at the lowest level of effectiveness in South Africa and Latin America, health experts say, the J&J vaccine works well. The company said it is working on a version of the vaccine aimed at the South African variant.
Dr. Anthony Fauci, President Biden’s chief medical advisor, said that current vaccines from Covid-19 are still expected to be effective against new variants of the virus, and the United States may approach a “degree of normality” in the fall if the highest part of the country is vaccinated by summer. Photo: Al Drago / Zuma Press
Write to Peter Loftus at peter.loftus@wsj.com
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