Making Vaccines: Licensure, Recommendations and Requirements


Licensure, the first of three processes, involves gaining approval from the Food and Drug Administration (FDA). As a result, it is the longest of these processes. It can take years, even decades, before pharmaceutical companies can actually start providing the vaccine. For example, the varicella vaccine took about 11 years to be licensed by the FDA.

Vaccines are usually made by first showing that they are safe and effective in experimental animals. Once this is established, the vaccine becomes an Investigational New Drug (IND) and the company is given an IND license to further study the safety and effectiveness of the vaccine in adults, and eventually, children. Again, these trials can take years, giving companies ample time to provide the FDA with proof of long-term safety and effectiveness.

Read more about pre-licensure studies »


The "recommendation" process begins only after the FDA licenses a vaccine. Doctors don't just decide to start giving the vaccine on their own. They seek the recommendations of the Advisory Committee on Immunization Practices (ACIP), which advises the Centers for Disease Control and Prevention (CDC), the Committee on Infectious Diseases of the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP).

While the FDA licensure process involves determining the risks versus the benefits of a particular vaccine, the recommendation process considers the costs versus the benefits. Here's the distinction:

  • The FDA examines vaccine safety by considering whether there are any risks (negative effects) associated with the vaccine. They ask: "Do these risks outweigh the benefits of the vaccine or vice versa?"
  • In addition to considering the risks and benefits of a vaccine, the ACIP, AAP and AAFP also examine the costs associated with immunizing all or just a segment of the population. For instance, with the chickenpox (varicella) vaccine: What is the cost of immunizing children compared with the potential savings in medical and non-medical costs from immunizing them? (An example of non-medical costs would be money lost by parents who miss work taking care of their child with chickenpox.)
  • Another part of the recommendation process is determining which groups of people within the population would benefit from the vaccine, and on what schedule the vaccine should be given. These decisions are made based on data previously presented to the FDA.


Just because a vaccine is recommended for use doesn't mean that it is required for use. State legislatures and health departments determine whether a vaccine is required. They examine the practicality of requiring it for every child within the state. Factored into this equation is whether a local or state government can afford to pay for the vaccines of children whose parents can't afford it.

From a parent's perspective, vaccine requirements shouldn't matter. If a vaccine is considered to be safe and effective by the FDA, and useful for children by the ACIP, AAP and AAFP, then the vaccine is of value and should be given. Local healthcare budgets, although they determine whether a vaccine is to be required for school entry, have little to do with whether a vaccine is safe, effective and useful.

Hear Dr. Offit explain how vaccines are tested by watching this short video, part of the Talking About Vaccines with Dr. Paul Offit video series.


Reviewed by Paul A. Offit, MD on October 09, 2019

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.