[Shethink13]

The flu vaccine is 40-60% effective depending on the year.

What are the parameters used to judge effectiveness. In other words, what is the definition of “effective” in this circumstance?

[444Flyer]

To small to fail.

“Covid-19 Vaccine Protocols Reveal That Trials Are Designed To Succeed”

https://www.forbes.com/sites/williamhaseltine/2020/09/23/covid-19-vaccine-protocols-reveal-that-trials-are-designed-to-succeed/?sh=707fb7bd5247

[2aProtectsTheRest]

Prevents contracting the disease would be the common meaning there.

Also, specifically for the flu vaccine, even in cases where the vaccinated person still contracted the flu, there is a huge drop in the risk of having a severe case requiring medical attention: https://www.cdc.gov/flu/spotlights/2017-2018/vaccine-reduces-risk-severe-illness.htm

So if you get the flu vaccine, there’s a 40-60% chance (depending on the year) that you won’t get the flu at all, and if you do get the flu, there’s a 37% lower chance you’ll wind up in the hospital and an 82% lower chance you’ll wind up in the ICU.

Not bad for a free 5-minute shot at Walgreens!