Facts About Johnson & Johnson Vaccine

Johnson & Johnson’s Belgian counterpart, Janssen Pharmaceutica, is working on approval of the third vaccine for COVID-19. Here’s what we know so far:

1. Johnson & Johnson’s vaccine is different from the other two—Pfizer’s and Moderna’s—in that it requires only one shot.
2. It is also far more stable than either of the other two. It will last for 3 months in an average home refrigerator and 2 years in an average home freezer. Its stability means that it can be transported without any extraordinary infrastructure or technology.
3. It uses adenovirus vector technology, meaning that a deactivated version of the common cold virus carries the DNA for COVID-19’s spike protein into cells. Once in, the spike protein triggers the immune system to respond.
4. This type of vaccine is easier to produce than the other two available now, which uses the newer mRNA technology.
5. The adenovirus vector technology used for Johnson & Johnson’s vaccine has been used for other vaccines in the past, including the Ebola vaccine. There is a lot of data on safety for this method.
6. We don’t yet know how well it will work. The company is expected to release data by the end of January. Anything over 80 percent would be good enough to warrant approval and widespread use.
7. If approved, Johnson & Johnson expects to be able to produce 1 billion doses by the end of the year.

Continued adherence to precautions—including avoiding gatherings outside your household, wearing a mask when in public, staying 6 feet from others, and washing hands regularly—are our best defense until vaccines are widely available and adopted. COVID is spreading in Vermont at the highest rates ever, so we need to be especially careful with precautions and vigilant in taking care of ourselves and others. 

Marie George, MD, FIDSA, is an infectious disease specialist at Southwestern Vermont Medical Center.