Vaccination is the administration of a vaccine to help the immune system develop protection from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. Vaccination is one of the most effective ways to prevent diseases. There are different types of vaccines like Live-attenuated vaccines, Inactivated vaccines. Subunit, recombinant, polysaccharide, and conjugate vaccines, Toxoid vaccines. These days DNA vaccines have also come into play for better therapeutic results. Children sice their are administered with a schedule of vaccination which prevent them from further diseases and infections like Chickenpox (varicella) vaccine, Diphtheria, tetanus, and pertussis vaccine (DTaP),Hepatitis A vaccine (HepA), Hepatitis B vaccine (HepB), Hib vaccine., Human papillomavirus (HPV) vaccine., Influenza vaccine., Measles, mumps, and rubella vaccine (MMR). Vaccines are available for these 18 dangerous or deadly diseases. Vaccines are very important for infants, but they're not all given immediately after birth. First vaccine was introduced for small pox by Edward Jenner. Vaccination relates to the knowledge of microbiology and the mechanism of infection of a disease. The severity/ pathogenicity with which a pathogen infects an organism also affect the efficiency of a vaccine and its administration.