Vaccines are part of a healthy individual’s life from birth to old age. Vaccines help infants and toddlers acquire immunity to otherwise lethal infections, such as measles, tetanus, and diphtheria, and are initiated as early as two months after birth. In adults and the elderly, vaccines help boost the immune system, fighting off bacteria that cause pneumonia and viruses that cause the flu. Some vaccines may have to be given again, in order to “reboot” the immune system. An immune system’s memory may decline over time, so vaccines such as tetanus require a “booster” dose. The influenza vaccine is unique among vaccines, as it is given annually because the influenza virus mutates (or changes) constantly. So, each year’s vaccine supply is engineered to create immunity to a few types of the virus judged most likely to be circulating in the upcoming flu season.
In spite of the demonstrated effectiveness of vaccines, an alarming development is that compliance with receiving vaccinations has decreased in the pediatric population. In the early 2000s, measles was at its lowest rate of incidence ever recorded, but avoidance of this vaccine in recent years has led to a resurgence of measles. And large numbers of adults (up to 40 percent of Medicare beneficiaries) do not take advantage of vaccines that can prevent serious illnesses, hospitalizations, and even death.