It’s time for everyone to be as informed as possible about the new COVID-19 vaccines.
In February 2021, the FDA issued an “emergency use authorization” (not FDA approval) for the Janssen COVID-19 vaccine from Johnson & Johnson for individuals 18 years old and older. Unlike the Pfizer and Moderna COVID-19 vaccines, which consist of a series of two injections, the Janssen Vaccine is only one shot. It also works using a slightly different mechanism — spike protein DNA instead of mRNA. The DNA for the spike protein of COVID-19 is attached to a common cold virus (adenovirus) and injected into the arm. It then enters the cells, and the DNA is activated to make spike proteins which are recognized by immune cells to produce antibodies. Because it is using the adenovirus as a vehicle, this vaccine also activates other immune cells.
Side effects reported in the study include headache, fatigue, pain at the injection site, nausea and muscle aches lasting one or two days.
The ongoing vaccine study consisting of 39,321 individuals (19,630 received the vaccine and 19,691 received saline placebo) was conducted in South Africa, certain countries in South America, Mexico and the U.S. This effectiveness study found the vaccine to be about 67 percent effective in preventing moderate to severe COVID-19 in the first 14 days after vaccination, and up to 85 percent effective in preventing severe COVID-19 after 28 days.
However, currently “data are not available to determine how long the vaccine will provide protection, nor is there evidence that the vaccine prevents transmission of SARS-CoV-2 from person to person.” Therefore, people who receive vaccines are recommended to continue to wear masks and socially distance until more is known about the potential risk of transmission even after vaccination.