- Vaccines act as training exercises for the immune system, helping the body recognize and respond to germs more effectively before serious illness develops.
- They may include fragments, dead, or weakened forms of germs to safely prepare the immune system.
- Some vaccines prevent symptoms altogether, while others make infections much milder if exposure occurs.
- Common mild side effects include a sore arm or brief fever, but vaccines prevent serious outcomes like pneumonia, disability, birth defects, and cancer.
- Immunity from vaccines often requires multiple doses or boosters, unlike natural infections that may trigger immunity after one exposure but at higher health risks.
- Annual vaccines, such as flu and COVID, are needed because respiratory viruses change frequently.
- Staying up to date with the AAP-recommended vaccine schedule ensures protection during the periods of highest risk for each illness.
- Examples include RSV, where the first infection season is most severe, rotavirus, which primarily threatens infants, and Hib, which affects mainly young children.
- Following the full vaccine schedule supports lifelong health and disease prevention for children.
What is a Vaccine
Vaccines are like practice runs for the immune system—teaching the body to fight germs before they can cause serious disease.
Susanne Tanski, MD, MPH, Pediatrics
