ABCs OF CHILDHOOD VACCINES HOW VACCINES WORK Terms To Remember • Antibodies: Special body proteins that fight viruses and bacteria • Immunologic Memory: The body's ability to respond to viruses or bacteria following immunization or infection; this ability often is retained for many years. • Community Immunity: The concept that immunizing all children who can be vaccinated protects those who have not been or cannot be vaccinated Even 2,500 Years Ago, People Knew Immunity Worked. • The time: 500 B.C. • The place: Greece • The observation: Greek physicians noticed that people who survived smallpox never got the disease again. • The insight: Becoming infected by certain diseases gives immunity. Vaccines Help Your Body Prepare. • Vaccines contain weakened or killed versions of viruses or bacteria. • They prepare your body to fight off disease. • When a vaccine gets into your body, you make antibodies-special proteins that fight the intruders. • Remember...what's in the vaccine is just strong enough to promote the body's response to make antibodies, but much weaker than the viruses or bacteria in their natural, or "wild," states. • If you haven't been vaccinated, wild viruses or bacteria can overwhelm your system, causing serious illness or even death. Antibodies Become Part of the Body's "Memory". • Once antibodies are produced in response to a vaccine, they become a permanent part of the body's immune system. • Then, if there is exposure to the natural or "wild" viruses or bacteria, the antibodies will fight off infections. • There's a scientific name for this: "immunologic memory." It means you'll respond quickly to viral or bacterial invasion. • "Immunologic memory" lasts longer for some vaccines than for others. Sometimes re-vaccination is required to maintain protection. Some Children Are Not Immunized, But They Can Be Protected. • Some parents choose not to have their children immunized for philosophical or religious reasons. • These unprotected children can be a source of infection to others who, for health reasons, can't be immunized. • A vaccinated child can help prevent disease from spreading. This is why it's so important for as many children as possible to stay fully vaccinated. • If too many people go unvaccinated, rare diseases may become common again. "Community Immunity" • Children who are immune are protected from disease. They can't get the disease and they can't give the disease. • If enough children are vaccinated against a disease then the disease cannot spread into their community. This is known as "Community Immunity". It's a Small World, and That's a Big Reason to Get Vaccinated. • Today, international travel takes millions of Americans to foreign countries every year-countries where vaccine-preventable diseases like polio or measles may be present. • Traveling to places like that can be deadly for children (and adults) unless they are immunized. • Some countries have serious infectious diseases that we don't routinely vaccinate for in the U.S., although vaccines are available. Check with your doctor before traveling. • Phone the CDC's Travelers' Hotline toll-free at 1-877-FYI-TRIP (877-394-8747). Key Facts • Vaccines give your body a "memory" of the disease-after you're vaccinated, you'll be ready to fight the disease if exposed. • Some children can't be vaccinated for medical reasons, and others aren't vaccinated for philosophical or religious reasons. • Vaccinating as many children as possible is the best way to protect everyone. • Whenever possible, vaccinate children before they travel to countries where childhood diseases persist. Diseases such as measles are still common in some countries. Additional Resources • Centers for Disease Control and Prevention website: www.cdc.gov. Click “Vaccines & Immunizations,” then click “NIP Home Page” in the right column. Or, go directly to www.cdc.gov/nip • National Immunization Hotline: 800-232-2522 • Parent's Guide to Childhood Immunization: Publication available online at www.cdc.gov/nip/publications/ • For information on vaccine testing and licensing: www.fda.gov • For information about local health care resources: www.naccho.gov or look under "public health" in the blue pages of your local phone book • For information on children's health insurance: www.insurekidsnow.gov • Additional ABCs of Childhood Vaccines slide shows cover the following topics: Risks of Not Vaccinating; Vaccine Safety; Natural Immunity; Primary Vaccinations