system
Given the following post, respond as if you're commenting on Reddit:
human
Why can’t we combine all of the vaccines into one big super vaccine and give it to babies at a young age instead of going through different rounds of vaccines at different ages?
gpt
The reality is that we are exposed to thousands of bacteria and viruses every day and our immune system is constantly fighting off the Invaders.

Why then is it so difficult to put 5 vaccines together and get it all done with in a single visit?

The purpose of vaccines is to provide long lasting protection from illnesses, whereas the body really cares about the here and now.

If we were to go include all the significant diseases in a single vaccine, then the macrophages which attack unknown Intruders would be divided between each illness. This is normal, but to get a long lasting effect from the vaccine we want the macrophages to predominantly be fighting off the disease if interest.

The macrophage presents the intruder to the T cells which learn how to recognize the  intruder. They go on to program the B cells to recognize and destroy the intruder.

By giving proportionally larger doses of individual vaccines, we can ensure that the immune response is large enough to provide a long lasting protection. If we were to as everything to a single shot or bodies would seek and eliminate the intruders but might not have a sufficient response- that is programming enough T cells- to give us long lasting protection.