Last reviewed by Faculty of Harvard Medical School
on February 3, 2011
By Henry H. Bernstein, D.O.
Harvard Medical School
and Claire McCarthy, M.D.
Boston Children's Hospital
So many immunizations! For parents bringing their children to the doctor, and for the children who are getting the shots, it can feel like more and more are being added every year. That's not exactly true, but the recommended vaccine schedule has expanded so that currently in the United States, it is recommended that all healthy children receive vaccinations against 11 potentially serious diseases.
Immunizing Your Children
Many parents understand the importance of immunizations for their children and have confidence that vaccines really do work. However, even though more than 80% of children an all-time high have received all their recommended immunizations, this still means almost one in every five children has not.
Some families don't immunize their children because they think that the diseases are too uncommon for their child to catch. However, not only are the diseases widespread around the world, but some are still diagnosed in our local communities. Every year children unnecessarily suffer severe illness or even death from diseases that could have been prevented.
Other families don't immunize their children because they are concerned about the safety of vaccines. But what people often don't realize is that all vaccines are carefully studied for many years in large numbers of children before they even are licensed for routine use.
Back to top
Vaccine Discovery and Early Testing
New vaccines are being studied every year, and they must travel a long road before they can be officially recommended.
First, a new vaccine generally goes through at least 10 to 15 years of development and evaluation first in the laboratory, where scientists try to make it just right, and then in clinical trials, where it is very carefully tested in humans.
Even to have a chance to test a vaccine in humans in a clinical trial, the manufacturer must file an investigational new drug (IND) application with the U.S. Food and Drug Administration (FDA). Then, after many years of data have been collected about the vaccine, the manufacturer submits a biologics license application (BLA) to the FDA. The BLA is the information that supports not only the actual licensure of the vaccine, but also the approval of the places where the vaccine will be made.
Back to top
The FDA Reviews the Data
During the following year, the FDA gives careful consideration to all of the data that have been submitted, with part of this process being done in a way that allows the public to have input. The FDA wants to know whether or not all of the information accurately supports that a vaccine is safe, helps the body's immune system make its own substances in the blood (antibodies) that protect against infection, and prevents children from getting the disease.
After this thoughtful review, the FDA either will license the vaccine, with a subsequent public announcement, or will ask the manufacturer for more information before making a final decision. Once a vaccine is licensed by the FDA (see www.fda.gov/cber/efoi/approve.htm ), the company that makes it can begin to market it, promoting the vaccine's use as written in the FDA-approved package insert.
So, at this stage, already the vaccine has been through years and years of study, with the FDA and the public looking at all of the results extremely carefully. But there is still much work to be done before a newly FDA-licensed vaccine is officially recommended for use in pediatric practice.
Back to top
Adding a New Vaccine to the Recommended List
The next step of finalizing recommendations for the use of a new vaccine involves committees of the American Academy of Pediatrics (AAP) and the U.S. Centers for Disease Control and Prevention (CDC), both of which help guide this process.
All immunization laws are made at the state level, and the specific vaccine requirements (for example, for entry into child care, school and college) may vary from state to state. In addition, state laws impact the financing of a new vaccine.
To figure out which vaccines they should require, state officials often rely on the recommendations of the AAP and CDC. The Committee on Infectious Diseases (COID) of the AAP is appointed by its board of directors, while the CDC's Advisory Committee on Immunization Practices (ACIP) is appointed by the secretary of the Department of Health and Human Services (HHS).
The ACIP is made up of clinicians, scientists, public health authorities (federal, state and local), statisticians and a consumer advocate. All actively participate in meetings and discussions, which are open to the public. ACIP recommendations must be approved by the director of the CDC and, once official, are published with supporting data in the CDC's Morbidity and Mortality Weekly Report (MMWR). This part from ACIP recommendations until MMWR publication may take several months.
At the same time, the COID and liaison representatives from professional medical organizations such as the American Academy of Family Physicians (AAFP), CDC, FDA, and NIH are discussing the new vaccine in order to create the specific recommendations for its use. In addition to reviewing that a vaccine is safe and effective, the COID and the AAP Board of Directors also consider the vaccine's impact on pediatric practice.
The AAP Board of Directors must approve all final recommendations. Once official, these recommendations are published in the journal Pediatrics and on the AAP Policy website. These recommendations are incorporated into the childhood and adolescent immunization schedule from the CDC, AAP and AAFP, which comes out every year in January.
Back to top
Public Education About the New Vaccine
Once the vaccine makes it to the recommended list, the professional organizations and governmental agencies collaborate to educate parents, caregivers and health care professionals concerning the vaccine's:
- Timing compared to other vaccines
- Mode of administration
- Availability for all children
Experts and politicians work together to ensure that coverage levels for immunizations do not vary based on which state and/or city you live in and that vaccines are available for every child, no matter how much they cost.
Once a vaccine is in use, it is continuously monitored for safety and effectiveness. Possible side effects are reported to VAERS (Vaccine Adverse Effect Reporting System, part of the Department of Health and Human Services), which gathers information about symptoms people have after immunization into one place so that doctors and scientists can figure out what is truly caused by a vaccine and what is coincidence. Sometimes, based on new information, changes are made in the timing or number of doses of vaccine in order to make it as safe and effective as possible.
Back to top
The Long Road to Healthier Children
The process for a vaccine to become an official routine part of pediatric practice is a long and continuous one, involving numerous experts. These safeguards should help parents have confidence in all the vaccines we use to prevent serious childhood diseases. With proper immunization of all healthy children, there hopefully will continue to be fewer and fewer cases of these diseases each year.
Back to top
Additional Sources for Vaccine Information:
Back to top
Henry H. Bernstein, D.O. is a senior lecturer in Pediatrics at Harvard Medical School. In addition, he is chief of General Academic Pediatrics at Children's Hospital at Dartmouth and professor of pediatrics at Dartmouth Medical School. He is the former associate chief of General Pediatrics and director of Primary Care at Children's Hospital Boston.
Claire McCarthy, M.D. is an assistant professor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and medical director of the Martha Eliot Health Center, a neighborhood health service of Children's Hospital. She is a senior medical editor for Harvard Health Publications.