In the past few weeks, Covid-19 vaccines created by Pfizer and Moderna have made headlines with their promising phase 3 trial results. Neck-in-neck in efficacy, both reported reductions in Covid-19 related disease higher than 90 percent. The Food and Drug Administration (FDA) could open the doors to widespread use of these vaccines, either through expanded access or emergency use authorization, as early as next month.
Although the reviews leading up to a stamp of regulatory approval are proceeding full speed ahead, one last bend in the road awaits—phase 4 (see Figure 1). This stage is designed to catch any adverse effects that didn’t surface or register as significant over the course of clinical trials. It also involves monitoring the production of the vaccines themselves. Given the accelerated timeline, long-term followup will be of particular importance for any Covid-19 vaccine authorized for human use under any authority, and a new commentary in Science Magazine shows why.
Originally published on Forbes (November 20, 2020)