[luztctti] Flu shot effectiveness each year

People get flu shots without knowing their effectiveness this year, even though it is measurable.

Designing each year's influenza vaccine is an educated guess that has to be made in the spring before the flu season starts, because the vaccine takes several months to manufacture.

Some people get a flu shot fairly early in the season.  By examining the incidence and determining the actual strains of flu in the early season, among people who did or did not get vaccinated, one can determine the effectiveness of the flu shot this year, how good that "educated guess" was last spring.  You, in a later wave, can then rationally decide whether it's worth spending the $30 to get vaccinated.  Why isn't this being measured and reported?  This seems well within the resources of, say, an investigative journalist of a news organization.

Vaccine makers don't want you to know this information.  If it's concluded that the flu shot is not effective this year, then they could lose hundreds of millions of dollars in the already manufactured doses.  They need consumers to pay for these now-useless shots to recoup their costs, so there's tremendous incentive to not measure and hide and suppress information.  How high up does it go?  The CDC currently recommends the flu shot unconditionally.

If this information gets out, vaccine manufacturers would probably pass on the cost of this financial risk to consumers, raising the price, so profits in years guessed right can recover losses in years guessed wrong.

Worse yet, almost unthinkably worse, vaccine manufacturers have incentive to purposely maliciously infect the population with each year's "educated guess" strains, ensuring the educated guess will be right.  It would not be very difficult, since the thing pretty much spreads itself after being introduced.  I can think of a dozen subtle ways this could be done. How would we detect this behavior?

It's possible that an "educated guess" strain might finally make it to the population (through not malicious means) later in the flu season, so measurements of flu early in the season might not be accurate.  How often this "late-introduction" occurs can also be measured scientifically (assuming no malice).  Flu mutates: the more time passes, the less likely it is for an "educated guess" to have been correct, so I predict "late-introduction" occurs rarely.

It's not that I'm against flu shots; I'm very much for them, and get one every year. One internet source suggest that the "educated guess" has been correct more than 50% of the time.