You probably want to learn how they make flu, H1N1, or any vaccines. In general, vaccines are made by incubating the virus itself into chicken eggs, then purifying the virus. (see this chart for reference)
As for H1N1, here’s a descriptive process of how the H1N1 vaccine is made:
First, “reverse genetics”, where scientists take the H and the N surface proteins from the H1N1 virus and mix them with a laboratory virus known as PR8.
This creates a harmless hybrid virus which can be used for the vaccine.
The second technique involves injecting both the H1N1 and PR8 viruses into eggs and allowing the hybrid strain to be created through a natural re-assortment of their genes.
All this will be injected into humans so your immune system develops antibodies against the virus:
The vaccine will work by tricking the immune system into thinking it has been infected with the H1N1 swine flu virus so that it creates antibodies against it.
Also check this video out of India making their H1N1 vaccine for reference:
Well, I’ve never got flu shots my whole life and just decided to suffer through flu season by getting them but you should probably get the shots.