Johnson & Johnson reported that its single-dose Covid-19 vaccine was protected against Covid-19 in a final-phase trial, 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. According to the company, the vaccine was 66% effective in a final study with about 44,000 volunteers aged 18 or older. This indicates that the trait protects adults from moderate to severe Covid-19, the disease caused by the coronavirus. When it focused on the specific prevention of serious diseases, the vaccine was even more effective, with a percentage of 85%. In comparison, an annual flu vaccine is considered to work well if it is 60% effective.
How does it compare to the effectiveness of Pfizer and Moderna shots?
The Pfizer Inc. Vaccine and its partner BioNTech SE was 95% effective in preventing people from getting Covid-19 disease in its final phase study, while the Modern vaccine was 94.1% effective. J&J’s shot didn’t work so well in the test. However, it can be tricky to compare between tests. And the timing of the tests could have played an important role, as J&J occurred as new variants of coronavirus appeared. Vaccines do not seem to work so 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 trial. Several vaccines have outperformed what health experts say to protect many people and provide the community with the immunity needed to move on to a post-pandemic life.
When can the vaccine be available?
J&J says it expects to ask the U.S. Food and Drug Administration in early February to authorize the use of its vaccine. If the FDA takes the same amount of time it did to review and authorize the first two Covid-19 vaccines (about three weeks), it could make a decision later in February or early March. J&J has been dosing while testing its shot, so it could be ready to ship supplies quickly after it gets regulators ’approval.
What are the side effects of the J&J vaccine?
The most common symptoms after vaccination were fatigue, headache, muscle aches, and pain at the injection site in an initial study. In the final phase study, J&J said a small percentage of subjects had a fever and there were no severe allergic reactions.