The polio vaccine is one of the true miracles of modern science. In the early 20th century, polio killed or paralyzed hundreds of thousands of people, as many as 20,000 cases of paralytic polio a year in the United States. With the development of vaccines in the 1950s and 1960s, the disease has been almost completely eradicated in the United States. While polio is no longer a high threat in the United States, the vaccine—children in America now receive the inactivated polio vaccine, or IPV—is still recommended. In 1988, the World Health Assembly agreed to eradicate polio in every country. That mission has been successful, but it is not yet complete—four countries still report cases of polio. Discontinuing vaccinations now could allow for a resurgence of worldwide.
The newest of the childhood vaccines, the human papillomavirus vaccine, is recommended for adolescent girls at age 11 or 12. The HPV virus is almost always present in cases of cervical cancer—which is called a "silent cancer" because it often isn't diagnosed until it has spread and becomes life-threatening.
Read why this vaccine is controversial for some parents.
Children generally begin getting the seasonal influenza vaccine—the yearly flu shot— after they at least 6 months old. Because the strain of influenza changes every year, a new shot will be needed every year. Flu shots are commonly available starting in September. Because of their weakened immune systems and the close contact of schools, it's recommended that children get flu shots every year until they are 19 years old.
Before the vaccine was approved for use in 1995, this disease—commonly called chicken pox—each year attacked as many as 4 million Americans, landed 10,000 in the hospital and killed 100 to 150. The vaccine prevents 80 to 90 percent of children from getting this disease. For those who were vaccinated yet still catch chicken pox, the vaccination has been show to reduce the severity of the case—just a few pox and only a mild fever. Some questions have been raised about how long a vaccination provides immunity. While the CDC reports that Japanese data show the vaccine provides immunity for 25 years, there are studies under way to determine if additional booster shots will be necessary.