Seven-month-old Soren Good became the youngest participant in Stanford Medicine’s Pfizer vaccine trial on April 21. He and his three-year-old brother Andel are two of nearly 150 children under the age of five who will be vaccinated during the first phase of Pfizer’s pediatric dose determination study in the United States.
“Initially the idea was that children don’t get very sick when they get COVID, but now we already understand that [have a low mortality rate], several children die from this virus every month in the United States, ”said the boys’ mother, Zina Good Ph.D. ’18, said.
Stanford’s arm of the nationwide trial is led by physicians Yvonne Maldonado, professor of pediatric infectious diseases, and Jenna Bollyky, clinical assistant professor of pediatrics and infectious diseases.
Good, a Stanford researcher who studies immunology herself, said that while her work is not directly related to COVID-19, her background knowledge of the immune system gave her the confidence to enroll her children in the study.
“I think there is quite a bit of variation in how comfortable families are in vaccinating their children,” she said. “It’s never been done in kids this age before, so I can understand it would be a bit scary for a lot of parents.”
Bollyky said the study is focused on finding the right vaccine dosage as well as safety. “It is very important that we work to find a safe and effective dose for children so that we can bring our entire country closer to herd immunity,” she said.
Children five to 12 years old were first given a dose of 10 micrograms in groups of 48 participants across the country. Once that was considered safe, the dosage escalated to 20 micrograms and then 30 micrograms. All participants in the trial are guaranteed to have received a vaccine: no one will receive a placebo. The trial is also open-label, meaning parents and researchers know what dose each child is getting.
For children under five, the dose was even smaller. Soren and Andel received a dose of three micrograms. They will return to the clinic three weeks after their first injection to receive their second dose. A week after that, they will have a blood test to measure antibody levels and see if the children have achieved adequate protection against COVID-19.
Bollyky explained that finding the right dose requires a good balance of safety and efficacy: “If we give too little, the body may not have enough to build the immune response, but if we give too much, the immune system can be overwhelmed. touch, causing unwanted side effects. ”
She and Maldonado also say vaccinating children is critical to stopping the spread of the disease.
“[Children are] about a quarter, or a little less than a quarter of our US population, ”Maldonado said in a statement to ABC7 News. “So it’s very important if we want to get immunity to herds, so that children are involved too.”
Good explained that, just like in adults, COVID-19 can have long-term health effects in children, even if they are only mildly symptomatic at first. These long-term effects, called “lung COVID” by scientists, occur in 13-15% of children infected with the virus. A study of children in Italy infected with COVID-19 found that nearly half of the children experienced symptoms that lasted longer than 120 days. Long-term COVID symptoms in children include prolonged lethargy, chest pain, gastrointestinal problems, and headaches. Nearly half of the children polled in a recent study said these symptoms interfered with their daily life.
“Because of lung damage from long-term COVID, some children cannot run or exercise as fast as they used to,” Good said. “Some children are seriously affected and find it difficult to climb the stairs or even get out of bed.” She hopes the vaccine will help protect her children from the disease, especially as schools and daycare centers reopen.
“With any medical treatment, you want to make sure the risks don’t outweigh the benefits,” said Bollyky. “We have so far seen an incredible advantage in the ability of these vaccines to prevent serious COVID diseases in adults, and we hope this will be the case in children as well.”
The researchers hope that parents who are now hesitant will feel more comfortable enrolling in the second phase of the study, for which enrollment begins May 17. By then they will have determined a dose for each age group, and the second phase will include a placebo group, with more emphasis on efficacy and understanding side effects.
Bollyky also hopes that the second phase of the process will better reflect the Bay Area’s racial and ethnic diversity, as many racial and ethnic groups have faced barriers to participating in these studies in the past. She explained that it is important for researchers to be “ more proactive about enrolling these patients, ” adding that the team has partnerships with local clinics across the Bay Area and will “ work with them to raise a population. take that [accurately reflects] our community. “
Good encouraged other parents to participate in the process, adding that it is important to talk to children about the pandemic as a whole so they can learn about the important role they can play in protecting their community.
“My three-year-old understands that there is a virus that can make people very sick, and he understands why it is important to wear a mask and social detachment at school,” she said. “He really likes planes, and he understands that if he wants to travel in the future, it’s very important that he gets vaccinated.”