Vaccine Question - What if it's always an either or ?

Just rambling thoughts as I wait for dinner...

Let's say we have a group of people.

One has a strong immune system and never gets sick.

One is average immune system. Gets sick every other year.

Third one gets sick all the time and has bad health in general.


All of them get a flu shot.

The first one has no flu symptoms all year.
The second gets a little bit sick for a day or so but is mostly fine.
Third one gets sick. Mild at first, but then has complications and dies.


Did the flu shot work?


Would the outcome be any different without it?

How do they rate the effectiveness? Do they say it has a 66% reduction in death?
But the first guy would have probably been fine without it and the second guy would have just had another day or 2 off work.
Third guy might have had lesser symptoms but still died.

I just don't think they can attribute effectiveness when there is no way to compare before and after for a single person.

It all comes down to each person's own immune system to do the work. Vaccines are not medicines and don't fight the invader in any way. They just sort of try to give you a diagram of the enemy, which may not even be necessary when you will see the real thing eventually. I don't think a "head start" is really worth what they have to do to give it to you.