Why can’t we take the immunity from and old person (who’s had lots of colds and flus) and use it to innoculate everyone?

Question

I’m laying here with a nasty cold and am curious… I don’t know where our immunity information is stored in our bodies, but why can’t we draw that immunity out of one person and inject it into someone else, and save them from getting sick from many versions of the rhinovirus?

In: 0

Answer 1

I am in no way a medical expert or professional. But, some diseases do work that way. When I was in the army, I had so many anthrax vaccinations that they took my plasma to either treat it or make more, I don’t remember which.

Answer 2

Common colds and flus change so often that the reality is the vaccines don’t proove to be effective that long. For example you get a new flu vaccine every year because the virus mutates to make previous vaccines less effective.

The second point is your body will ‘forget’ over time you will generally forget about the immunity you have. Just look at the 2 doses and booster COVID-19 vaccines.

Answer 3

The immune system is really complicated, but “immunity” in this sense is sort of “stored” in certain long-lived cells that your body makes and antibodies it learns to make. The problem is that immunity is basically a form of learned knowledge, where your body needs to learn by experience. Sure, you and I each have a small number of expert white blood cells in our bodies that could help with fighting off a given cold, but finding them is harder than finding a needle in a haystack, and even if you could get them to the other person they wouldn’t stimulate that person’s immune system correctly (and instead would get destroyed as an invading cell.)

There are some ways of simply giving someone a big injection of pre-formed antibodies from another source, but none of them are perfect. It’s a temporary solution because you’re not stimulating your own antibody production, and your immune system may get pretty mad about all these foreign proteins suddenly showing up, so it can cause a serious reaction.

ELI5: Imagine that somewhere in the U.S., there’s a single expert who knows how to help Ukraine defeat Russia, but we don’t know their name or face, and they don’t speak a word of Ukrainian, and aren’t allowed in Ukraine.