The question of vaccinations and the side effects that accompany them has been the subject of an omnipresent debate in society and in medicine for several years. Some continue to believe that vaccinations are harmful and actually promote disease, but the truth is that the concept of immunization is one of the most significant advances in scientific history that has led to the prevention of countless diseases and epidemics across the world. Yet, despite the overall improvement in public health, the use of vaccination remains a controversial and constantly questioned concern. Critics of vaccination say serious side effects associated with vaccines have been underestimated, underfunded and rarely studied. This is, however, false. Vaccinations are a necessary part of society because they prevent the spread of major diseases, reduce the severity of the disease, strengthen the immune system and, therefore, protect the population from possible epidemics. The definition of a vaccination, as stated by the Encyclopedia Britannica, is "a suspension of weakened, killed or fragmented microorganisms or toxins or antibodies or lymphocytes that is administered primarily to prevent disease" ( Encyclopedia Britannica). Vaccines stimulate the immune system to attack the specific harmful agent, then ensure that the antibodies remain sensitized in case the agent re-emerges in the system. Obviously, this can be useful when trying to prevent a disease, or any other disease, since the antibodies specific to this type of disease remain present in the body for fear that the disease will return. Since infants are extremely susceptible to infirmities, many are vaccinated within the first month of life. This helps... middle of paper ......ed reported cases of measles, and less than a hundred reported cases of poliovirus. Additionally, studies in the United States have found that the diphtheria, pertussis, and tetanus (DPT) vaccine is 90% effective in preventing disease (Zimmerman). id=60286Encyclopedia Britannica. “Science and technology ::Vaccine.” Encyclopedia Britannica. Encyclopedia Britannica, Web. .http://internetreviewofbooks.com/sep10/the_pox_and_the_covenant.htmlhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1200696/http://www.vaccinateyourbaby.org/why/preventing.cfmZimmerman, RK . (2000). Childhood immunizations, part 1: routine vaccinations. Journal of Family Practice, 49, (9), 22-33. Retrieved March 12, 2005 from EBSCOhost database. http://www.whale.to/a/moth.html