Experts in vaccines and vaccination — including pediatricians — work together throughout the year to update the Recommended Child and Adolescent Immunization Schedule for ages 18 years or younger.

The schedule is approved by the American Academy of Pediatrics and based on ongoing reviews of the most recent scientific data for each of the recommended vaccines and other immunizations. To be included in the recommended schedule, the vaccines must be licensed by the Food and Drug Administration.

The schedule also recommends the age when children and teens should receive each vaccine or immunization.

Following this schedule gives children the best protection from diseases. If you have questions about vaccines, don't hesitate to ask your pediatrician. They know your child's health history and can talk with you about specific vaccines.

The current schedule recommended by the American Academy of Pediatrics is considered the best way to protect children and keep them healthy. Some children may need additional vaccines beyond the routine schedule. For example, if your child has a chronic condition or takes medicine that weakens their immune system, they may need a booster dose or a different type of vaccine. Your pediatrician can discuss what approach is best.

A vaccine may be given in one or more doses. The timing for each dose of a vaccine is based on what age a child's immune system provides the best protection after vaccination. The schedule is also designed to make sure that we protect children when they are at the highest risk from the diseases we’re trying to protect them from. This is why most of the vaccines we give children are when they are very young – that is when most of these diseases pose the highest risk.

Getting your child vaccinated on the recommended schedule is the best way to protect them and keep them healthy. If your child misses a vaccine dose, you don't need to start over. Call your pediatrician's office, and they can schedule the next visit.

It's really not a good idea to spread out or delay vaccines, for several reasons. Children need to get their vaccines on schedule so they can benefit from all the protection that vaccines give. While it may be hard to think about, the fact is that young babies are the ones who get hospitalized and die more often from the diseases we are trying to prevent with vaccines. That’s why it’s so important to vaccinate them as soon as possible.

Also, the recommended schedule is designed to work best with a child's immune system at certain ages and at specific time intervals between doses. There is no research to show that a child would be equally protected against diseases with a very different schedule. There is also no scientific reason why spreading out the shots would be safer. What we do know, thought, is that any length of time without immunizations is a time without protection against these potentially terrible diseases.

Researchers are always studying how long vaccine protection lasts, how many doses we need and how much time between doses works best. That is why your child needs an influenza shot every year, for example, but for another vaccine, your child may develop lifelong protection from just a few doses spaced months or years apart.

Pediatricians want you to have reliable, complete and science-based information. This allows you to make the best decision for your child about vaccination. Unfortunately, there are a few doctors who go against the existing science, often for personal gain, such as selling books or advertisements on their websites. The overwhelming majority of pediatricians in the United States strongly support following the recommended schedule. Most parents follow the schedule for their kids.

When most people in the community have immunity to a disease, it is less likely for that disease to spread. If many people in a community decide to follow an alternative schedule or skip vaccines, diseases can spread much more quickly. That’s what we’re seeing with the measles outbreaks currently happening in the U.S.

Multiple shots in one visit do not “overwhelm” a child's immune system. We know vaccines are safe -- including when multiple shots are given together. A child’s immune system responds to literally thousands of things in the course of a normal day – through crawling around the house, eating and even simply breathing. The proteins – also called “antigens” – that children respond to in vaccines are truly a drop in the bucket compared to normal, everyday exposures.

If your child is sick, talk with your pediatrician. Often, they can still get vaccinated even if they have a mild illness like a cold, earache, low fever or diarrhea. Vaccination does not put any extra burden on the immune system and catching up on vaccines that same day saves time because your child will not need to make an extra appointment.

Smallpox is the only disease that has been eradicated completely by vaccines, so we still need vaccines for the other diseases that can spread in our communities. Vaccines equip our body's immune system so it can recognize, respond, and get rid of an infection.

For example, the measles, mumps, rubella (MMR) vaccine has worked very well in the U.S. for decades. Lately, fewer people have had all recommended doses of MMR vaccine. This has allowed the illnesses it prevented to start to rise again. The vast majority of people infected with measles in ongoing 2025 measles outbreaks have been unvaccinated.

It is because of vaccines and community immunity that children rarely get serious diseases like tetanus, measles, rubella, meningitis and polio. We cannot predict which children will have a mild case and who will get severely sick when infected. So, we must continue using every tool to protect children, including vaccines.

A vaccine does not cause illness in healthy people because the virus or bacteria in the vaccine is either not alive or very, very weak. Vaccines have active ingredients that give information to your child's immune system, so it knows how to defend itself from these diseases.

There are some vaccines that use a live, weakened virus. This type of vaccine very rarely can cause illness for people who have severe conditions impacting their immune system, like someone being treated for cancer. Their doctor may instead provide a different form of the vaccine or advise them to not get that one vaccine.

And no, vaccines do not cause autism. Children get several vaccines between ages 1 and 2. This is also the time some children start to show symptoms of autism. Although they happen around the same time, one does not cause the other. Through extensive research, science has confirmed that vaccines and autism – or other neurodevelopmental disorders -- are not related.

Mild to moderate side effects are a normal and expected part of how vaccines work. Sometimes when you get a vaccine, you may get a fever, soreness at the site of injection or body aches. This is really just a sign of your body's immune system's work. After the vaccine does its job, it quickly leaves your body. The side effects go away shortly, too.

Very rarely, more serious reactions can occur from a vaccine, and pediatricians are trained to recognize these very rare reactions. From decades of research, though, we know that the risks of getting these diseases is far greater. All things considered, the vaccines in the schedule recommended by the American Academy of Pediatrics are truly a gift – they help children thrive and grow, which is ultimately the goal of every parent and pediatrician.

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Sean T. O'Leary, MD, MPH, FAAP, is a pediatric infectious diseases expert at the University of Colorado. He is the chair of the AAP Committee on Infectious Diseases.

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