That’s a fact.. the flu shot reduces the risk of flu illness by between 40% and 60% because there’s so many variants of flu’s and so many variants of flu shots. When you get a flu shot it’s against whatever flu they think may be most prevalent or what they think may work best for you.
It DOES NOT reduce the symptoms and you can still get the flu if you have the wrong shot.
Flu shot does reduce the severity of symptoms. This has been well studied for a long, long time.
https://www.cdc.gov/flu/prevent/misconceptions.htm
https://www.cdc.gov/flu/vaccines-work/vaccineeffect.htm
https://www.mayoclinic.org/diseases-conditions/flu/in-depth/flu-shots/art-20048000
https://www.webmd.com/vaccines/how-effective-is-flu-vaccine
https://www.livescience.com/40279-flu-shot-information.html
https://www.livescience.com/27758-flu-shot-hospitalization-older-adults.html
https://www.healthpartners.com/blog/flu-shot-myths/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684491/
https://www.hcplive.com/view/flu-vaccine-reduces-virus-severity-patients-prevention