After a brief pause in use, the Centers for Disease Control and Prevention (CDC) and U.S. Food and Drug Administration (FDA) have recommended that the use of the Johnson & Johnson COVID-19 vaccine should resume. The vaccine was initially given emergency use authorization in February 2021 and is estimated to provide, by mid-year, an additional 100 million safe and effective doses of protection against the disease that has claimed the lives of more than 572,000 Americans.
Use of the Johnson & Johnson vaccine was paused for 11 days due to reports of very rare, but severe blood clots in 6 women, all under age 50, who received the vaccine. The agencies reviewed the available data and found that the vaccine's proven benefits outweigh the known risks. However, the CDC recommends that women younger than 50 years old should be aware of the risk and know that there are 2 other COVID-19 vaccine options for which this risk has not been seen.
The vaccine's unique benefits
According to Johnson & Johnson, their vaccine requires only 1 dose and can be kept at normal refrigeration temperatures, making it easy to both store and distribute. The other COVID-19 vaccines currently being used in the U.S, made by Pfizer and Moderna, require 2 doses for full protection and freezing storage temperatures.
"The fact that we have a third vaccine given emergency use authorization in the U.S. within a year is amazing," says Dr. Abisola Olulade, a family medicine doctor with Sharp Rees-Stealy Medical Group. "And the '1 and done' approach is great. I've heard of people forgetting or unable to get - or choosing to forego - their second dose of the other vaccines and we won't have that problem with this single-dose option."
A different technology
Unlike the Pfizer and Moderna mRNA vaccines, the Johnson & Johnson COVID-19 vaccine is an adenovirus viral vector vaccine. This vaccine uses a harmless common cold virus that has been altered to deliver a piece of genetic code to the body's cells to mimic coronavirus infection. The cells make the surface spike protein of the coronavirus, and then the immune system responds, priming it to attack any future coronavirus infection.
Clinical trials demonstrated that the Johnson & Johnson vaccine is 72% effective in preventing moderate to severe COVID-19 disease in the U.S. While both the Pfizer and Moderna vaccines provide over 94% efficacy against severe illness, the Johnson & Johnson vaccine joins them in providing 100% protection against hospitalization and death.
Additionally, this newest vaccine was tested later in the pandemic than the others, making the comparison of the vaccines, Dr. Olulade says, "like comparing apples to oranges." Both the Pfizer and Moderna vaccines were tested early in the pandemic. Conversely, the Johnson & Johnson clinical trials were held at a time when COVID-19 infections had already surged across the globe and virus variants had developed, suggesting it is also effective against newer strains.
Take the shot you can get
Dr. Olulade stresses that the differences in vaccine efficacy should not cause anyone to be hesitant to receive the vaccine. "When we look at the effectiveness of our annual flu vaccines, the average is 40% to 60%," she says. "And they are considered excellent vaccines. The same is true of the Johnson & Johnson COVID-19 vaccine."
Like other experts, Dr. Olulade strongly recommends that people should receive whatever COVID-19 vaccine is available to them once they become eligible.
"The best vaccine is the one that you can get," she says. "And even after you're vaccinated, it is important to continue to take all the regular prevention measures - wear a face mask, wash your hands often and practice social distancing - so that things don't get worse before we can reach herd immunity."
This story was updated in April 2021 to include the latest Johnson & Johnson vaccine information.