Pediatric Immunization

Public health professionals: As of March 16, all changes to federal vaccine recommendations made between June 2025 and March 2026 have been put on hold. Please check the changes that are currently on hold to ensure you are sharing timely, accurate information about the federal vaccine recommendations.

Talking Points

In January 2026, the U.S. Centers for Disease Control and Prevention (CDC) and U.S. Department of Health and Human Services (HHS) announced significant changes to the United States’ recommended pediatric immunization schedule without following established procedures or providing a scientific rationale. These updates have raised concerns among public health and healthcare professionals regarding potential parental confusion about vaccine access and safety, which could lead to decreased uptake and an increase in preventable illness. PHCC remains committed to clarity and evidence-based messaging and will continue to rely on the American Academy of Pediatrics (AAP) as an expert source on pediatric immunization for our Pediatric Immunization Talking Points. 

About Pediatric Immunization

1. Following the American Academy of Pediatrics (AAP) schedule of recommended vaccines is the most effective way to protect infants, children, and teens against 18 preventable, potentially serious diseases. The immunizations recommended in the AAP schedule are covered by private insurance, Medicaid, the Children’s Health Insurance Program, and Vaccines for Children. Individuals without private insurance through their employer can purchase coverage through the Affordable Care Act, and all associated plans will cover AAP-recommended immunizations. The AAP’s schedule is endorsed by 12 medical and health organizations representing more than 1 million clinicians, physicians, pharmacists, and other pediatric healthcare professionals. 
2. AAP recommends a schedule of pediatric immunizations tailored to the United States and may differer from that used in other countries. These recommendations consider factors such as population size and demographics, its healthcare system, and its history of disease to determine the vaccines that are essential for preventing the spread of disease and severe illness.
3. The recommended immunization schedule begins at birth to protect infants before they are exposed to diseases such as measles, polio, and whooping cough. As children grow, they need to receive additional immunizations to extend their protection against these diseases. Lower vaccination rates in the United States have led to an increase in the spread of disease and a higher risk of severe disease for young children and their families.
   • During 2025, measles cases in the United States reached their highest levels in over 30 years. This has happened as measles vaccination rates have fallen over the last several years to levels below the 95% vaccination rate threshold needed to protect communities against measles outbreaks. Measles vaccination is recommended in children ages 12 months and older and in some cases as early as 6 months of age.
     • Options: Two vaccines can help prevent measles in children 12 months to 12 years old: measles-mumps-rubella (MMR) vaccine and the measles-mumps-rubella-varicella (MMRV) vaccine. Both vaccines are combination vaccines, which means they protect against several diseases in a single dose to reduce the number of injections a person receives and the number of visits to a healthcare professional. There are no separate vaccines to protect against measles, rubella, or mumps individually.
   • The 2024-25 flu season resulted in the highest number of pediatric deaths from the flu over the last 15 years. The 2025-26 flu season is also severe, with flu rates growing across the United States. This is happening  as flu vaccination rates have declined in children in the U.S. Vaccination is the best protection against a potentially life-threatening flu infection. Flu vaccination is recommended for everyone 6 months and older, ideally in September or October. While getting vaccinated earlier in the season is recommended, vaccination at any time during flu season, typically between October and May, can prevent severe flu-related illness.

Safety and Effectiveness

1. Safety: In the United States, vaccines undergo years of careful research and testing before they’re available to the public. Once available, many health experts and organizations continuously monitor vaccines to ensure their ongoing safety and effectiveness. 
   • Thimerosal is appearing more frequently in the news cycle, causing concern among parents and caregivers. Also known as ethylmercury, thimerosal is a preservative used in some types of influenza vaccines that the human body can process with minimal risk. Ethylmercury is sometimes confused with methylmercury, a higher-risk mercury compound that is not used in vaccines.
   • There is no scientific evidence that thimerosal is harmful. Nevertheless, thimerosal is not used in any vaccine on the AAP’s childhood vaccination schedule. For more information about thimerosal, visit PHCC’s “Vaccine Development, Safety, and Effectiveness” topic page.
2. Effectiveness: Without vaccines, children and their adult caregivers are at higher risk for the serious side effects of preventable diseases, including disability and death. Among children born between 1994 and 2023, routine childhood vaccinations prevented: 
   • 508 million cases of illness 
   • 32 million hospitalizations 
   • 1.13 million deaths

Side Effects

1. The most common side effects of pediatric vaccines are very minor, such as mild pain and swelling in the area where the shot was given, a low-grade fever, and irritability. 
2. Severe allergic reactions may also occur, but they are very rare. 

Staying on Schedule

1. Document each vaccine your child receives and keep these records in a safe place. Keeping track of your child’s progress within the immunization schedule helps ensure your child stays healthy. 
   • Additionally, your child may need to show documentation of their vaccines to go to school and after-school activities, travel abroad, and apply for certain jobs.  
2. If you do not have your child’s immunization records: contact the doctor(s) and/or clinic(s) who have previously given your child vaccines. You can also contact your state’s immunization registry or your child’s school. 
3. If you cannot find your child’s immunization records: talk to a healthcare provider about the best next steps for keeping your child safe and healthy. 

Communicating about the Childhood Immunization Schedule 

Public health communicators are increasingly receiving questions about why children receive multiple vaccines during the first few years of life. The recommended childhood immunization schedule from the American Academy of Pediatrics (AAP) is designed to protect children when they are most vulnerable to serious diseases. 

The AAP immunization schedule is endorsed by a broad group of leading medical and health organizations, representing pediatricians, family physicians, nurses, pharmacists, infectious disease specialists, and other health care professionals. Communicators can help build understanding by explaining how the schedule is developed, why vaccines are recommended at specific ages, and how children’s immune systems respond to vaccines.

1. The childhood immunization schedule is designed to protect children when they are most vulnerable.
   • Babies and young children are at higher risk for serious illness because their immune systems are still developing.
   • Diseases such as measles, whooping cough (pertussis), pneumococcal disease, and meningitis can lead to hospitalization, long-term complications, or death in young children.
   • Vaccines are recommended before children are most likely to be exposed to these diseases, helping them build protection that is ready when they need it most.
   • Delaying recommended vaccines or skipping recommended doses extends the period during which children remain vulnerable to preventable diseases.
2. Children’s immune systems are built to respond to vaccines.
   • From birth, children’s immune systems respond to thousands of bacteria and viruses through everyday activities like eating, breathing, crawling, and playing.
   • Vaccines contain only a small number of antigens — the parts of a virus or bacteria that train the immune system to recognize disease. Although children receive more vaccines today than in previous generations, today’s vaccines contain fewer antigens than older vaccines.
   • A healthy child’s immune system can respond to multiple vaccines during the same visit, while continuing to respond to the many germs encountered every day.
   • Receiving recommended vaccines during the same appointment helps children build protection sooner while reducing the number of healthcare visits families need to make.
3. Every vaccine and every recommended dose serves a specific purpose.
   • Each vaccine protects against a different disease that can cause serious illness during infancy and childhood.
   • Some vaccines require multiple doses because the immune system develops stronger, longer-lasting protection over time. Getting only one of multiple doses, or delaying the recommended time between doses, will not provide the full protection needed to prevent serious illness.
   • The timing of each vaccine and each dose is based on when children are most likely to benefit from protection, ensuring children get the right protection at the right time.
   • Delaying or spreading out vaccines can leave children unprotected for longer without providing any proven benefit. The recommended schedule is designed to protect children at the ages when they are most vulnerable while minimizing unnecessary visits and missed opportunities for vaccination.
4. The childhood immunization schedule reflects decades of research and ongoing review.
   • The recommended schedule is informed by decades of research on childhood diseases, immune system development, and vaccine performance.
   • Researchers evaluate when children are most likely to be exposed to diseases, how well vaccines work at different ages, how long protection lasts, and whether vaccines can be given during the same visit.
   • Vaccine recommendations are regularly reviewed and updated as new information becomes available. For example, after reviewing data showing that one dose of varicella vaccine did not provide enough protection to prevent all cases and outbreaks, the AAP updated its guidance to recommend a routine two-dose varicella vaccine schedule for children.
   • The schedule is designed to provide children with protection at the ages when vaccines offer the greatest benefit.
5. Vaccination helps children, families, and communities thrive.
   • Staying up to date on recommended vaccines helps reduce the risk of serious illness, hospitalization, disability, and death from vaccine-preventable diseases.
   • Vaccination helps children spend more time learning, playing, and growing.
   • Babies may be too young to receive certain vaccines, so they also rely on those around them, including older children, to get vaccinated to prevent the spread of disease. Keeping communities protected against vaccine-preventable diseases helps reduce outbreaks and protects those at greatest risk of severe illness.

Sources

Children’s Hospital of Philadelphia Vaccine Education Center. The Science Behind the Vaccine Schedule.

American Academy of Pediatrics (AAP). All About the Recommended Immunization Schedule.

American Academy of Pediatrics (AAP). Prevention of Varicella: Recommendations for Use of Varicella Vaccines in Children, Including a Recommendation for a Routine 2-Dose Varicella Immunization Schedule.