Every year tetanus kills 300,000 newborns and 30,000 birth mothers who were not properly vaccinated. Very recently, an increased number of tetanus cases in younger persons has been observed in the U.S. among intravenous drug users, particularly heroin users. Tetanus is infectious, but not contagious, so unlike other vaccine-preventable diseases, immunization by members of the community will not protect others from the disease. Because tetanus bacteria is widespread in the environment, tetanus can only be prevented by immunization. If vaccination against tetanus were stopped, persons of all ages in the U.S. would be susceptible to this serious disease.
Mumps is usually a mild viral disease.
However, rare conditions such as swelling of the brain, nerves, and spinal cord can lead to serious side effects such as paralysis, seizures, and fluid in the brain. Serious side effects of mumps are more common among adults than children. An increase in spontaneous abortions has been found among women who develop mumps during the first trimester of pregnancy. An estimated 212,000 cases of mumps occurred in the U.S. in 1964. After vaccine licensure in 1967, reports of mumps decreased rapidly.