11^th European Epidemiology and Public Health Congress

Vaccines

A vaccine can gives active immunity against specific injurious diseases by stimulating the immune system to attack the agent. After stimulated by a vaccine, the antibody-producing cells, which are ready to acknowledge to the agent should it ever gain entry to the body. A vaccine also confers passive immunity by providing antibodies or lymphocytes already formed by an animal or human donor. Vaccines are generally administered by injection, but some are given orally or even nasally. Vaccines applied to mucosal surfaces, seem to stimulate a greater antibody reaction and may be the most effective route of administration. In addition to the development of memory B cells, vaccination is also favourable at the population level. When a sufficient number of individuals in a population are immune to a disease, as would occur if a huge proportion of a population were vaccinated, herd immunity is achieved.