It is most serious in infants under one year of age. Measles causes a high fever, rash, and cold- like symptoms. It can lead to hearing loss, pneumonia, brain damage, and even death. Measles spreads so easily that a child who has not been immunized will most likely get the disease if exposed to it. Mumps can cause headache, fever, swelling of the glands of the jaw and neck, and swelling of the testicles in adolescents and adults.
Polio can be fatal.
Persons infected with the polio virus shed the virus in stool and can transmit the virus to others. It is spread by coughing and sneezing or direct contact with drainage from the rash. Among children, a common complication is bacterial infection of the skin lesions. Varicella is more serious in adults and persons with impaired immune systems. If a woman has this disease while pregnant, it can cause birth defects and infant death.