In the most simplistic terms, flu vaccines including the H1N1 and seasonal flu vaccines are made from a dead virus (found in pre-filled syringes and vials) or a greatly weakened live virus (found in the nasal sprays). These viruses are grown in eggs and then they go through a processing period. The vaccines are then painstaking tested by the FDA and then hopefully approved or else it’s back to the drawing and the process is started all over again. However, vaccines have been made the same way for many years and in recent years have had no problems passing the FDA’s strict requirements. Finally the vaccines are placed in vials or syringes and made available to the public.  

Once you receive the vaccine, your body reacts to the dead or weakened virus by producing its own army of antibodies to protect you. This army of antibodies that the vaccine helped your body create assists your immune system to attack and destroy the live virus if it enters your body. 

That’s about as simple as I can make it …………. I hope this explanation helps.