CDC finds flu shots 42% effective this season, better than some recent years

[BumRushDaShow]

2. It's never been that high

About the highest I've seen is maybe 60% effective.

Because of the long lag time between determining what they think will be circulating and actually doing the manufacturing process (using eggs), means that it's often a miss by the time the vaccines are ready before the fall.

This is why there is a lot of work being done to try to get an effective mRNA flu vaccine because the manufacturing of that can happen much quicker and thus they can "guestimate" the variant later in the year before the fall (meaning a better chance the "guess" is spot on).