How Does an Adenovirus Vaccine Work?

On Saturday, the FDA approved a third vaccine to help rid the world of the COVID-19 pandemic. This is a different type of vaccine: an adenovirus vaccine. How does it work?

Scientists have taken an adenovirus, which is the kind of virus that causes colds, and changed it so it cannot make us sick (cool, right?). Once injected into your arm, the virus finds your cells and shares a piece of DNA that tells your cells how to make a COVID-19 spike protein.

From that point on, it works in a very similar way to the mRNA vaccines from Pfizer and Moderna, which I described back when they were first approved by the FDA back in December.

The adenovirus in the vaccine cannot replicate (make more of itself) and it cannot change our DNA. It cannot give us (or anyone around us) COVID-19. It can make us feel a little icky for a day or two, which is a normal part of developing immunity.

You know what’s even more exciting? The Johnson & Johnson vaccine only requires one dose and doesn’t need extremely cold storage like the mRNA vaccine! That will make it much, much easier to distribute.

The one downside of the new Johnson & Johnson vaccine is that it appears to be a little less effective than the Pfizer and Moderna ones. The previously approved vaccines are 90-95% effective at preventing COVID-19, but the new one is only about 75%. However, with the tight supply of vaccines and the challenges of distribution, you will want to get any vaccine that’s offered to you. It might be a long time before you get your choice of vaccines. All of the available vaccines are safe, and the more people that get them, the sooner we can stop the spread of COVID-19. I will certainly be getting mine at the first opportunity.

Remember, the goal is herd immunity. We want as many people vaccinated as possible, as soon as possible. We’re almost at the end. We can do it!

Sources:

https://www.cdc.gov/vaccines/covid-19/hcp/viral-vector-vaccine-basics.html

https://www.pbs.org/newshour/health/how-does-the-johnson-johnson-vaccine-compare-to-other-coronavirus-vaccines