CDC: Vaccines a public health success

ATLANTA, Oct. 20 (UPI) -- Vaccines are one of the greatest success stories in public health, having eliminated smallpox and nearly rid the world of polio, U.S. health officials said.

Public health officials at the Centers for Disease Control and Prevention said in a statement that by law before a vaccine can be licensed in the United States it must undergo very extensive testing.

"Once in use, vaccines are continually monitored for safety and efficacy," the statement said. "Vaccines are our best defense against infectious diseases, but no vaccine is 100 percent safe or 100 percent effective."

Before a vaccine is licensed in the United States, the U.S. Food and Drug Administration requires testing to ensure safety. After it is licensed, the FDA requires the vaccine's manufacturer to submit samples from each vaccine lot, potency and purity, the statement said.

Each person is unique and may react differently to an immunization but in most people vaccines are effective and often only cause mild reactions such as fever or soreness at the injection site. Some people may experience a more serious side effect, such as an allergic reaction, but these events are very rare.

If the reaction is severe call a doctor or take the person to a doctor immediately and ask the doctor, nurse, or health department to file a Vaccine Adverse Event Reporting System form, or call VAERS at 1-800-822-7967.

The system collects reports from healthcare providers, vaccine manufacturers and the general public. An adverse event is any health problem or side effect that happens after a vaccination.