According to the World Health Organization (WHO), immunization is the process by which a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine.
For most vaccines, a weakened form of the disease germ is injected into a person’s body. The body’s immune system detects the invading germs (antigens) and produces antibodies to fight them. Those antibodies stay in the person for a long time, in many cases, for the rest of their lives. If the person is ever exposed to the disease, their immune system will be able to fight it off with the antibodies it already has, without the person ever getting sick.
Vaccines are effective.
Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases. Most childhood vaccines are 90%-99% effective in preventing disease, and more than 20 life-threatening diseases can now be prevented by immunization. It is estimated that immunizations prevent between 2 and 3 million deaths each year.
Today in the United States, vaccinated children and teens are protected from 16 harmful diseases:
- Haemophilus influenzae type B (Hib)
- Hepatitis A
- Hepatitis B
- Human Papillomavirus (HPV)
- Influenza (Flu)
- Meningococcal Infections
- Pertussis (Whooping Cough)
- Pneumococcal Infections
- Rubella (German Measles)
- Varicella (Chicken Pox)
Vaccines are safe.
Before a vaccine is licensed in the United States, the Food and Drug Administration (FDA) reviews all aspects of the development, including how and where it’s made, its ingredients, and the studies that have been conducted in people who have received the vaccine. Results are then reviewed again by the CDC, the AAP, and the American Academy of Family Physicians before a licensed vaccine is officially recommended to be given to children. Additionally, every lot of the vaccine is tested to ensure quality and safety. The FDA also continues to regularly inspect places where vaccines are made, and vaccines continue to be studied and tested. All doctors must report certain side effects of vaccines to the FDA and CDC. Parents can also file reports online at www.vaers.hhs.gov.
Vaccines may have mild side effects, such as swelling, redness, or tenderness where the shot was given, but those don’t last long. It is very rare for side effects to be serious. However, a child’s pediatrician should be contacted right away if the child has any serious symptoms such as:
- Very high fever (greater than 103 degrees) and is younger than 3 months
- Hives or black and blue areas at places an injection was not given
Vaccines save lives and protect against the spread of disease.
Many diseases that are vaccinated against in the United States are rarely seen in this country. That does not mean immunization for these diseases is not necessary. In some parts of the world, vaccine-preventable diseases are still common. These may be brought into the US by Americans who travel or from others visiting the US. Those who are unvaccinated are at risk of catching these diseases.
Herd immunity is the benefit everyone receives from a vaccinated population once immunization reaches a large majority. When enough people are vaccinated, everyone, including those who are too young or too sick to be immunized, receives some sort of protection from the spread of diseases.
Getting vaccinated is better than getting the disease. In the case that a vaccinated child does get the disease, the symptoms are typically less serious than in a child who hasn’t been vaccinated. Additionally, the booster shots are just as important as the initial vaccines. These are designed to continue immunity, building on the previous vaccines’ effectiveness.
Children’s Hospital of Philadelphia
Graphic courtesy of the CDC