An Ignoble Experiment: Tracking the COVID-19 vaccine: How does the Johnson and Johnson vaccine compare to others?

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CORONAVIRUS UPDATES

Feb 28, 2021

The U.S. Food and Drug Administration has authorized the use of the Johnson & Johnson coronavirus vaccine in adults.

Maureen Ferran, a virologist at the Rochester Institute of Technology, explains how this third authorized vaccine works and explores the differences between it and the Moderna and Pfizer–BioNTech vaccines that are already in use.

The Johnson & Johnson vaccine is what’s called a viral vector vaccine.

To create this vaccine, the Johnson & Johnson team took a harmless adenovirus – the viral vector – and replaced a small piece of its genetic instructions with coronavirus genes for the SARS-CoV-2 spike protein.

This approach is not new. Johnson & Johnson used a similar method to make its Ebola vaccine, and the AstraZeneca-Oxford COVID-19 vaccine is also an adenovirus viral vector vaccine.

The most basic difference is that the Johnson & Johnson vaccine is an adenovirus vector vaccine, while the Moderna and Pfizer vaccines are both mRNA vaccines. Messenger RNA vaccines use genetic instructions from the coronavirus to tell a person’s cells to make the spike protein, but these don’t use another virus as a vector. There are many practical differences, too.