by Christina Echegaray
Monroe Carell Jr. Children’s Hospital at Vanderbilt is set to begin a phase 2/3 clinical trial to study the safety and efficacy of the Moderna COVID-19 vaccine in children.
Researchers in the Vanderbilt Vaccine Research Program will enroll at least 100 healthy children, ages 6 months to 11 years, over the course of one to two months. The trials will follow an age de-escalation, dose escalation approach, where small doses of the vaccine are evaluated in older children first, followed by younger children. This allows the researchers to decide the best dose to use in different age groups. In this case, the study will first look at children 6 to 11 years old; then 2- to 5-year-olds; and finally, ages 6 months to up to 2 years.
“If our children are going to be in school and grandparents are going to enjoy extended visits with grandchildren, we may have to vaccinate our children. Therefore, we need to evaluate the vaccine in children in order to optimize the use of COVID-19 vaccines,” said C. Buddy Creech, MD, MPH, director of the Vanderbilt Vaccine Research Program and associate professor of Pediatric Infectious Diseases.
Creech said age de-escalation is used to ensure the appropriate vaccine dose and effectiveness for each age group, especially since immune system behavior varies among different ages.
“We don’t do age de-escalation studies for every vaccine. While children have generally been spared by this virus, we still see children who have a challenging time with COVID. We still have more to understand about why some children get the disease and why some do not,” Creech said.
The first part of the Phase 2/3 study will evaluate the safety of the vaccine in children and determine the right dose children need for it to elicit an effective immune response to ward off COVID-19 or prevent severe disease. All children in the first part of this study will receive the vaccine in a two-shot series one month apart. The first children participating will receive either 25 mcg, 50 mcg, or the current EUA dose of 100 mcg, depending on their age. Then, a specific dose may be used based on the immune response and the presence of side effects, such as fever, arm pain or achiness.
“We want to do the studies in children and not simply assume that what works for adults works for them,” Creech said.
The second part of the study will be a randomized, placebo-controlled study across all the pediatric age groups. The participants will receive two shots, also a month apart, of either the vaccine or an inactive placebo. They will be followed for approximately one year.
Vanderbilt is one of several centers across the U.S. and Canada participating in the phase 2/3 trial, which seeks to enroll approximately 6,750 children.
The study will be conducted through the NIH-funded Vanderbilt Vaccine and Treatment Evaluation Unit (VTEU) as part of the Infectious Diseases Clinical Research Consortium (IDCRC). Creech is principal investigator of the Vanderbilt VTEU.
The clinical trials in children under age 12 come after the U.S. Food and Drug Administration approved the Moderna and Pfizer vaccines for adults under an emergency use authorization. Other centers around the country are currently conducting clinical trials of the vaccine in children 12 and older.
Vanderbilt University Medical Center is also one of the centers participating in the trials
that look at the Moderna and Johnson & Johnson COVID-19 vaccines in adults. Those studies will last for approximately two years.
The Moderna mRNA vaccine contains the genetic sequence for the spike protein on the surface of SARS-CoV-2, the virus that causes COVID-19. The spike protein enables the virus to bind and fuse with the membrane of certain types of cells in the body, the first step in infection.
“In the meantime, we need to do what we can to vaccinate everyone else. The way the pandemic ends is for enough of us to be immunized so the virus can’t find a foothold anywhere,” Creech said.
The Vanderbilt study is funded in whole or in part with federal funds from the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Department of Health and Human Services and VTEU Cooperative Agreement/Grant number 1UM1 AI148452.
