I would say it doesn't come out of a man other than through blood. my reasoning for this is simple, messenger rna is simply a protein molecule that closely resembles the viral infection it is trying to structurally mimic AND is identifiable by the immune system. when the mrna protein is spotted by the immune system the system then creates antibodies to remove the protein and those antibodies happen to fight off the real viral infection in the process. once the proteins are eliminated the antibodies are remembered but the virus is still unidentifiable by the body so if the body hasn't killed off the infection then another shot will be needed until the infection is gone.

this changes when we talk about coronavirus however because corona is a tiny virus inhabiting a larger virus inhabiting the body and the larger virus is identifiable by the immune system hencethe need for only one mrna shot, unless the tiny virus happens to mutate then a new mrna shot will be needed.

I hope this information was helpful because I needed to see a lot of clinical trials at clinicaltrials.gov to get the information for and share with you. I also broke it down to not so complex because big words are confusing.

the earth is most likely flat. if it wasn't why would pilots use azimuthal equidistant maps to navigate the air and seas? not to forget you can't buy no stop flight tickets from certain places that are too far from each other on said azimuthal map that otherwise would be easily possible on a sphere. theres also been proof of there not being a curve of the planet from cameras stationed on the beach recording a ship in the ocean traveling away and well surpassing the curve that a spherical planet would have because on a sphere the ship wouldn't be observable after the milage would be passed. I mean it's even on the flag of the United Nations. believe whatever you want but science and unpurchasable plane tickets do not lie.