Vaccinations are an important tool in the fight against serious preventable diseases.  Some people would rather gain immunity from having the disease itself, rather than receiving a vaccine, but this can be dangerous as natural infections can cause severe complications and be deadly. Even with relatively mild diseases like chickenpox it is impossible to predict who may get seriously ill.  Although many of these diseases are rare in the U.S., they do exist in other parts of the world and can be brought into the country, putting unvaccinated American children at risk. Vaccination is the best way to protect against these potentially deadly diseases.