What does COVID vaccine efficacy and COVID vaccine effectiveness mean? And which vaccine is best for you?
Efficacy refers to how well a vaccine works in a controlled setting, as in a clinical trial. Effectiveness, on the other hand, refers to how well it works in a real-world setting.
The Pfizer vaccine had a 95 percent efficacy in clinical trials. A U.S. study showed that the Moderna vaccine had a 90 percent efficacy in a recent clinical trial.
But how does that translate to the real world? How well will they work for you?
Americans have been getting shots in arms since December. The CDC followed 4,000 individuals who’d received shots over a period of months. It found both the Pfizer and Moderna vaccines to be 90 percent effective at preventing infection.
These are both two-dose vaccines. But even after the first dose, the vaccines proved 80 percent effective at preventing infection.
So which vaccine should you get? Health experts say there is no “best” vaccine. Take whichever one is available to you. Because it’s more important to get protected from the coronavirus than to shop around for a preferred vaccine.
You can expect to gain maximum protection 14 to 28 days after both shots. Even with the current variants, the vaccines prevent 90 percent of infections. They also keep you from becoming seriously ill, if you get infected.