
1. Early protection
The immunization schedule protects your child early in life before they come in contact with vaccine-preventable diseases. Young babies are at high risk of getting sick and dying if they get one of these diseases. For example, pertussis (whooping cough) can be severe and even deadly for infants. That's why babies start getting the pertussis vaccine at two months of age.

2. Ideal timing
- How your child’s immune system responds to vaccines at specific ages.
- How likely your child is to come in contact with a particular disease and suffer complications from that disease at specific ages.

3. Every vaccine and dose matters
Each vaccine protects against a specific disease that could cause serious harm. Some vaccines require multiple doses to build strong enough immunity to protect your child or to boost immunity that decreases with time. Other vaccines need two doses because a child may not respond to the first dose.

4. Protecting others
Children who are not immunized on time are at risk of getting a vaccine-preventable disease and spreading it to others, including those most at-risk, like babies too young to get immunized and people who can't get vaccines for medical reasons. When you immunize your child on time, you don’t just protect them - you help protect your family, friends, and community, too.

5. Not following the schedule is risky
Delaying, skipping, or spacing out vaccines leaves children at risk of getting diseases at an age at which they are most likely to have serious complications. Spacing out vaccines also means more clinic visits and periods of discomfort for your child, which may increase your child’s risk of developing needle fears.
Article: The Problem with Dr. Bob’s Alternative Vaccine Schedule (Pediatrics, 2009).
