Pfizer's Inclusion of Kids In Vaccine Trials Is a Sign of Progress, Experts Say

Doctor injecting vaccination in arm of little child girl

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Key Takeaways

  • Pfizer has gained FDA approval to begin testing its coronavirus vaccine in children 12 and older.
  • Experts say that including kids in clinical trials is crucial to the overall development of a vaccine that will protect both children and adults from COVID-19.
  • According to its website, Pfizer has already enrolled more than 39,000 volunteers in its study. More than 34,000 of those volunteers have already received a second vaccination.

Pfizer, a United States pharmaceutical company, announced in October that it has received permission from the U.S. Food and Drug Administration (FDA) to begin enrolling children as young as 12 in its coronavirus vaccine trials.

“By doing so, we will be able to better understand the potential safety and efficacy of the vaccine in individuals from more ages and backgrounds,” the company said in an updated statement.

This will be the first COVID-19 vaccine trial in the U.S. to include children. As of October, Pfizer is one of four U.S. companies to have vaccines in Phase 3 clinical trials.

Pfizer had already expanded Phase 3 of its trial to include children 16 and older, as well as people with chronic, stable human immunodeficiency virus (HIV), Hepatitis C, and Hepatitis B.

Why Test a COVID-19 Vaccine in Children?

Prior to Pfizer gaining approval to begin testing in children, experts published a report in the journal Clinical Infectious Diseases stating the importance of such testing.

“The direct COVID-19 impact upon children is greater than that observed for a number of other pathogens for which we now have effective pediatric vaccines,” the report notes. “Additionally, the role of children in SARS-CoV-2 transmission has clearly been underappreciated. Carefully conducted Phase 2 clinical trials can adequately address potential COVID-19 vaccine safety concerns.”

Suzanne Pham, MD

We cannot overcome the spread of this virus unless we vaccinate our children.

— Suzanne Pham, MD

Sharon Nachman, MD, chief of the Division of Pediatric Infectious Diseases at Stony Brook Children’s Hospital in New York, agrees with the report, telling Verywell that “pediatricians are very interested in seeing the details of the study and how will the vaccine perform in children.”

There are specific benefits to testing the vaccine in children, according to Nachman. The researchers will be able to assess the short- and long-term immune response, which includes figuring out whether the vaccine dose used in adults is necessary for children, or if they would have a similar immune response to a lower dose.

Nachman says it's also important to note that because coronavirus in adults can be preceded by their exposure to an asymptomatic infection in children, establishing a vaccine to treat an entire family could “go a long way to cut transmission at home and in the community.”

Suzanne Pham, MD, associate chief medical officer at Weiss Memorial Hospital in Chicago, tells Verywell that the sooner kids can be vaccinated, the sooner transmission rates will decrease.

"By effectively vaccinating children, the risk of children transmitting the virus within the community will lessen, especially to those high-risk people who are more susceptible to severe or critical illness," Pham tells Verywell. “This will allow for schools to begin re-opening and activities vital for the development of our children to resume in a controlled fashion. We cannot overcome the spread of this virus unless we vaccinate our children. We must have enough herd immunity in society to be able to prevent spread.” 

How Do Vaccine Trials Begin?

Pham explains that for a vaccine to be tested—on adults or children—a company must first submit an Investigational New Drug (IND) application to the FDA.

The application will describe the vaccine, how it is manufactured, and what quality control tests are to be used. The application also includes data from animal testing that demonstrates that the vaccine is safe for initial testing in humans.

As the FDA explains, the application process has several steps:

During a new drug's early preclinical development, the sponsor's primary goal is to determine if the product is reasonably safe for initial use in humans and if the compound exhibits pharmacological activity that justifies commercial development.

When a product is identified as a viable candidate for further development, the sponsor then focuses on collecting the data and information necessary to establish that the product will not expose humans to unreasonable risks when used in limited, early-stage clinical studies.

The vaccine will then undergo Phase 1 trials, which Pham explains are “safety and immunogenicity studies done in a small number of human subjects who are closely monitored.”

“Phase 2 consists of dose-ranging studies and is expanded to larger numbers (hundreds) of human subjects,” says Pham. “Then, Phase 3 trials seek to enroll thousands of human subjects to document effectiveness and continue looking at safety data.” 

According to its website, Pfizer has enrolled more than 39,000 volunteers in its study. More than 34,000 of them have received a second dose of the vaccine.

What This Means For You

A Phase 3 clinical trial that includes testing a COVID-19 vaccine in children is a sign of progress. However, a vaccine cannot be rushed. Finalizing results takes time to protect the safety of trial participants, as well as adults and children who will eventually receive the finished version of the vaccine.

 The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

5 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. Pfizer. Coronavirus COVID-19 vaccine update: latest developments.

  2. National Institutes of Health (NIH). Fourth large-scale COVID-19 vaccine trial begins in the United States.

  3. Pfizer. Pfizer and BioNTech propose expansion of pivotal COVID-19 vaccine trial.

  4. Anderson EJ, Campbell JD, Creech CB, Frenck R, Kamidani S, Munoz FM, et al. Warp speed for COVID-19 vaccines: Why are children stuck in neutral?. Clinical Infectious Diseases. doi:10.1093/cid/ciaa1425

  5. U.S. Food and Drug Administration, Center for Drug Evaluation and Research. Investigational new drug (IND) application.

By Caroline Shannon Karasik
Caroline Shannon Karasik is a writer based in Pittsburgh, PA. In addition to Verywell, her work has appeared in several publications, including Good Housekeeping, Women's Health and Well+Good.