Vaccines are basically Gene Wilder and Cleavon Little in Blazing Saddles or the Three Amigos.
Q. How exactly do vaccines work if they don't prevent a virus from entering your body?
A. OK, so do you ever watch those cop dramas on TV? They do a bunch of research, figure out who the bad guy is, and then âput out a BOLOâ to find the bad guy?
Thatâs kind of what a vaccine is.
Itâs the Wanted poster that they give to the cops (which is your immune system) so that they know what the bad guy looks like, so that when they run into the bad guy, they recognize him and take him out. Itâs also the specialist that comes in and trains the locals on how to deal with this particular bad guy.
A vaccine âtrainsâ your own immune system to recognize the virus. Usually, the immune system can only learn what a virus âlooksâ like by actually coming in contact with a virus. But since they wonât know itâs a âbad guyâ until it does âbad guyâ stuff, that gives the virus time to run around doing damage before the immune system a) figures out that itâs the bad guy and b) calls in all the troops for the manhunt.
This is bad. This is reactive. This necessarily requires damage to the body first. And a lot of time, the damage can be too extensive to repair, or it can kill you before your immune system has the time to mount an effective response. Or worse, the damage is to the immune system itself, preventing any defense of any illness at all.
So a vaccine delivers something that *looks* like the virus but doesnât do any damage. A mock-up, a model, a training dummy. That way, the immune system learns to recognize it first, and it rallies the troops immediately and has them on standby, ready to go, before the virus ever enters the system. So when the virus DOES finally enter (if it does), the SWAT team is right there, already geared up and trained on this guyâs specific tactics.
There may still be a firefight. The bad guy might still win. But itâs WAY WAY WAY less likely if all systems are on alert and geared up and waiting to ambush the virus, rather than allowing the virus the opportunity to sneak in and start sabotaging stuff without the immune system knowing about it.
Vaccines are the warning poster, the BOLO, the call to action, telling your own body that there is an imminent threat on the horizon, go to DEFCON 5, batten down the hatches, and get ready for war. Then your own body does what it can to prepare itself based on the information itâs given in the warning poster / vaccine.
With enough warning and the proper information, our bodies can usually mount an effective defense, but itâs still gonna be a fight and some people are immunocompromised (meaning that their body doesnât have, like, a functional SWAT team, they have a dinky little rural sheriffâs office with 2 deputies and a couple of shotguns and thatâs it). So itâs really important that all the surrounding towns (people) mount a good defense, that way the virus never even makes it into the county and the people with the little rural immune systems never have to take on the big fight that they canât even hope to win. And if enough counties have enough towns on alert, we remove all the possible places that the bad guy can go to ground and hide, and if it canât go anyway, it dies out.
Vaccines are the early warning system and training montage. Your body is still doing all the work. For most people, thatâs very effective as long as the intel the body has about the virus is good. For some people, they require everyone else to keep the virus out of the population around them because theyâre not equipped to mount their own defense. As long as we reach a minimum number of vaccinated people in the population (80% or more get the âwarning systemâ), and we get the required âcontinuing educationâ training (i.e. booster shots) for those viruses that need it, our collective biology does a pretty good job of repelling the invaders ourselves.
https://www.quora.com/How-exactly-do-vaccines-work-if-they-dont-prevent-a-virus-from-entering-your-body/answer/Joreth-Innkeeper