When Corey Corrigan’s daughter Harper arrived nine weeks early in September 2019, her and her husband’s lives were turned upside down. Harper was diagnosed with a rare brain malformation called lissencephaly, which can cause delayed development, seizures and other conditions.
Post-birth, her stay in the hospital would stretch into spring 2022. The Covid-19 pandemic made things all the more complicated. The family hunkered down in isolation to protect Harper from the virus.
Today, as a toddler, Harper has never had the chance to play with another child. Without a Covid-19 vaccine, she’s too vulnerable to the virus to risk exposure. “Her therapists say it would be so beneficial for her to be around other children, to mirror what they’re doing and learn,” says Corrigan. “But it’s just too dangerous for her.”
The Corrigans are one of 20 million American families with children under the age of 5.
Covid-19 vaccines have been authorized for people aged 5 and older, but the process to greenlight a shot for the smallest children has dragged on for months.
While it’s still not exactly clear when the vaccine will be available, Moderna recently submitted an emergency use application to the Food and Drug Administration for a low-dose Covid-19 vaccine for children under the age of 6. Pfizer has announced plans to submit an authorization application for its own three-dose shot for kids under 5 by early June.
In the meantime, parents and caregivers have grown increasingly frustrated with the lengthy delays in authorizing a vaccine for small children, especially as many Americans, already vaccinated or boosted, return to normal life.
“We feel like we’re living in this alternate reality,” Corrigan says. “Everyone is trying to tell us that it’s over, but that’s not really true. It’s challenging to not feel hopeless.”
What’s caused the delay in a Covid-19 vaccine for young children?
Though the FDA has assured the public that it’s moving as quickly as safety allows, medical experts say the delay in a vaccine for the littlest kids has been necessary to ensure the correct dosage, and to address any risks, however small, associated with vaccination.
“The biggest challenge in the under-5 age group is that their smaller size usually requires a lower dose to optimize vaccine effectiveness and minimize side effects,” says Dr. Matthew Linam, a pediatric infectious disease specialist at Children’s Healthcare of Atlanta. “This requires more testing than what is often needed for older children.”
The process to create a safe vaccine is painstaking, requiring lengthy trials in which volunteers receive the shot and are monitored over several months for side effects and immune response. If the trial results are unsatisfactory, vaccine researchers may have to tweak different variables, like dosage and timing, before beginning a new trial.
Where does Moderna’s vaccine stand?
At the end of April, Moderna submitted its Covid-19 vaccine for kids under age 6 to the FDA for emergency use authorization. Its vaccine is two doses administered 28 days apart. Each shot equals one-quarter of the adult shot. During its trial period, Moderna reported no serious Covid-19 cases among vaccinated kids, and any breakthrough cases were mild.
The vaccine for young children has a similar efficacy to the mRNA adult vaccines in protecting patients against the still-dominant Omicron variant, with an efficacy around 51 percent for children aged 6 months to 2 years and 37 percent for kids aged 2 to 6 years.
Where does Pfizer’s vaccine stand?
Pfizer’s vaccine for older kids is already approved, but its vaccine for kids 5 and under was delayed during clinical trials. While it planned to seek emergency approval from the FDA in February, its trials showed the shot wasn’t quite effective enough yet.
Like Moderna’s, a dose of Pfizer’s vaccine for young children contains a lower dose — around one-tenth — of an adult shot. Early data showed two doses didn’t produce enough of an immune response in kids ages 2 to 4, so the company decided to add a third shot to the regimen.
Results from this trial are expected soon. Pfizer could submit an emergency use application as soon as June.
What does the timeline look like for approval?
The FDA is still evaluating data submitted by Moderna about its vaccine for kids under 6 years. An FDA spokesperson says he can’t predict how long the evaluation of Moderna’s application will take, but assures patients that the agency is moving “as quickly as possible using a science-based approach.”
Last month, the FDA released a tentative schedule for its vaccine advisory committee, which will meet several times in June to evaluate new Covid-19 vaccine data, including Moderna’s emergency use application. Given that timeline, medical experts familiar with the process have said vaccines for this age group could be available sometime in July.
Depending on when Pfizer submits its own application, the advisory committee could evaluate that vaccine at the same time.