How Childhood Vaccine Schedules Are Determined

Federal committee ensures safety and effectiveness

As researchers have found new and safer ways to combat infectious diseases, the schedule of vaccines in the United States has grown substantially. Today, fully vaccinated children and teens are protected from 16 different diseases—far more than their parents or grandparents

While most parents have embraced these changes, some worry about the increasing number and/or frequency of vaccines that their children receive and wonder if they are actually necessary and safe.

Doctor Applying Bandage After Giving Vaccine
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It's natural to be cautious about anything that affects your child's health. With so much chatter about vaccines, particularly on social media, you may have many questions that you need reliable answers to so you can feel confident about your decisions.

Gaining a better understanding of how the childhood vaccination schedule is developed, and why it is widely considered the safest and most effective way to protect kids from potentially serious preventable infections, can help tremendously.

Who Determines the Vaccine Schedule?

While the Food and Drug Administration (FDA) is tasked with deciding if a vaccine can be sold in the United States, it is the Advisory Committee on Immunization Practices (ACIP) that makes recommendations on which vaccines should be used and when.

The ACIP is a voluntary committee within the Centers for Disease Control of Prevention (CDC) that consists of 15 voting members chosen by the Secretary of the Department of Health and Human Services (HHS) after a formal application and nomination process.

Of the group, 14 members are doctors, researchers, and infectious disease experts with extensive experience in public health and vaccines. At least one member must be a representative who is tasked with overseeing the public's interest.

In addition, representatives from dozens of professional organizations are invited to offer insights and recommendations to the committee (albeit without voting rights). These include, among others:

  • American Academy of Pediatrics (AAP)
  • American Academy of Family Physicians (AAFP)
  • American College of Nurse-Midwives (ACNM)
  • American College of Obstetricians and Gynecologists (ACOG)
  • American College of Physicians (ACP)

To protect against conflicts of interest, applicants with current ties to vaccine manufacturers are excluded. Similarly, panel members must abstain from voting if they are conducting research on a vaccine under consideration or being funded by companies directly or indirectly involved with the vaccine.

The Review Process

The ACIP meets three times a year to review current research and update the vaccine schedule if necessary. To make the process as transparent as possible, the committee posts their agendas and meeting minutes on the CDC website. All ACIP meetings are open to the public and broadcast live via a webcast.

Between meetings, members break into working groups to focus on specific vaccines and infectious diseases. They then brief the entire committee on their findings. If the evidence strongly supports the use of a vaccine, non-voting representatives are invited to offer their views before an official vote is called.

Among the questions the panel will ask:

  • How effective is the vaccine in preventing mild, moderate, and severe symptoms of a disease?
  • How effective is the vaccine in preventing the community spread of infection?
  • Is the vaccine safe and effective when given at specific ages?
  • Is it safe for use with other vaccines given at the same time?
  • How practical are the recommendations for the public and medical community alike?

After these issues are debated and discussed, the committee votes to include, remove, or modify the vaccine recommendations. Thereafter, a revised schedule is published at the beginning of each calendar year or sooner if there is a public health emergency like COVID-19.

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Implementing Vaccine Recommendations

Recommendations made by ACIP are published in the Federal Register (the official journal of the federal government) and adopted by the CDC, APA, and others as the standard of practice.

ACIP statements are official federal recommendations for the use of vaccines in the United States. Both private insurers and the federal government use the recommendations to determine which vaccines they will pay for.

Vaccines recommended by ACIP are automatically added to the list of Essential Health Benefits (EHB) under the Affordable Care Act, meaning that they are covered without cost-sharing for recipients of Medicaid and Medicare, as well for those under most private health plans

It should be noted, however, that ACIP recommendations do not dictate schools' list of required vaccinations. That is up to the state governments to decide.

An example is the ACIP recommendation for the use of the human papillomavirus (HPV) vaccine in girls and boys between the ages of 11 and 12. Because HPV is sexually transmitted, some parent groups have successfully lobbied against adding it to the school vaccination schedule in some states.

Changing Recommendations

Changes in the vaccination schedules shouldn't be considered cast in stone. All ACIP recommendations are subject to ongoing scrutiny and may require rapid reversals if a new piece of evidence questions a vaccine's efficacy or safety.

One such is example is ACIP's decision to drop its recommendation of the intranasal flu vaccine spray (FluMist) in 2016. Based on efficacy studies from 2013 to 2015, the vaccine was found to be substantially less effective than previously thought. It was immediately removed from the ACIP list once this was discovered.

Two years later, the manufacturer reformulated the vaccine and presented new data to the committee demonstrating its improved efficacy. After a committee vote of 12 (in favor) to 2 (against), FluMist was once again reinstated to the recommended list for the 2018-2019 flu season.

Exceptions and Modifications

While the immunization schedule is designed to be applied to all children of a specific age group—broadly categorized as birth to 15 months and 18 months to 18 years—there are some kids who may need to follow an adjusted schedule.

This includes children in whom a vaccination may be contraindicated or pose serious health risks. Among the examples:

The ACIP takes special cases into consideration and includes footnotes in their recommendations to guide the appropriate use of vaccines and offer alternatives, if available.

Considering Conflicts

Some parents delay or forgo certain vaccines based on recommendations of well-credentialed "experts" they have found online.

As reasonable as their arguments may seem, or as concerning as their points may sound, avoiding the vaccines recommended by the ACIP only puts your child at avoidable risk. The consequences of this impact not only your child but others around them.

Such is the case with measles, an infectious disease declared eliminated in the United States in 2000. However, with the growth of the anti-vaxxing movement in this country and others, measles has had a major comeback. It is feared that other childhood diseases may do the same.

If you are concerned about a vaccine's safety, don't keep silent and ignore the ACIP recommendations. Speak with your child's pediatrician, focusing not only on the possible harms of a vaccine but the possible risks of not getting vaccinated.

And remember: Always verify any vaccine information you hear about by consulting authoritative sources, such as healthcare providers, professional health organizations, government agencies, and peer-reviewed journals.

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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Table 1. Recommended child and adolescent immunization schedule for ages 18 years or younger, United States, 2021. Updated February 12, 2021.

  2. Centers for Disease Control and Prevention. Advisory Committee on Immunization Practices (ACIP): General committee-related information. Updated October 8, 2020.

  3. National Vaccine Advisory Committee. Recommendations from the National Vaccine Advisory Committee: Standards for adult immunization practice. Public Health Rep. 2014 Mar-Apr;129(2):115-23. doi:10.1177/003335491412900203

  4. Centers for Disease Control and Prevention. Preventive services coverage. Updated May 5, 2020.

  5. Newman PA, Logie CH, Lacombe-Duncan A. et al. Parents’ uptake of human papillomavirus vaccines for their children: a systematic review and meta-analysis of observational studies. BMJ Open. 2018;8(4):e019206. doi:10.1136/bmjopen-2017-019206

  6. Centers for Disease Control and Prevention. Prevention and control of seasonal influenza with vaccines recommendations of the Advisory Committee on Immunization Practices — United States, 2016–17 Influenza Season. Updated August 26, 2016.

  7. Grohskopf LA, Sokolow LZ, Broder KR, et al. Prevention and control of seasonal influenza with vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018-19 influenza season. Morbidity Mortality Weekly Rep. 2018 Aug 24;67(3):1-20.

  8. Centers for Disease Control and Prevention. Vaccine recommendations and guidelines of the ACIP: Contraindications and precautions. Updated February 2, 2021.

  9. Centers for Disease Control and Prevention. Measles history. Updated November 5, 2020.