A mom of 3 kids under 5 drove across state lines to get them all into a COVID vaccine trial, and she says it was worth it

• Moderna recently announced it will seek FDA authorization for its pediatric COVID-19 vaccine.
• That move would allow children from 6 months to 6 years old to be vaccinated against the virus.

In the winter of 2021, as eager adults across the US were elbowing to get their first doses of the COVID-19 vaccines, mom Linsey Sandeen was furiously Googling and making phone calls from her home in Iowa, desperately trying to figure out the fastest way to vaccinate her three children under the age of 5.

"Moderna I think got annoyed with me because I kept calling like every month, 'OK. Are you ready for them? Are you ready for them??'" she remembered.

After roughly eight months of waiting and calling regularly, her persistence finally paid off in October 2021, when Sandeen got her three youngsters enrolled into a Nebraska clinical trial of Moderna's COVID-19 vaccine for children under 6 years old. Her youngest, Lincoln, was 11 months old at the time, daughter Zoey was 3, and eldest Zander was 4.

They're three of the roughly 6,700 children across the US and Canada, aged 6 months to 6 years, included in the company's Phase 2/3 vaccine trial — a final safety and efficacy assessment before the vaccine can be considered for wider use among babies, toddlers, and young children across North America.

"Hopefully they got the vaccine," their dad, Zach said. "Crossed our fingers."

The Sandeen parents don't know if their kids were injected with two lower-dose (25 μg, compared to 100 μg for adults) shots of Moderna's COVID-19 vaccine or not. In clinical trials like this one, some kids receive a fake (placebo) injection, so regulators can compare unvaccinated and vaccinated study participants head-to-head to assess how well the vaccine really works.

The Sandeen family is quietly hoping they will find out soon: Moderna last week announced plans to apply to the US Food and Drug Administration for an Emergency Use Authorization to provide their 25 μg mRNA COVID-19 vaccine to kids 6 months to 6 years old. If the FDA approves of their data, that could happen this spring.

Blood draws, temperature checks, and symptom diaries

To be included in the trial, the Sandeens drove roughly two and a half hours from their home in Iowa to the nearest Moderna trial site, which was at a clinic in Hastings, Nebraska.

They visited once in October, to get shot number 1, then again in November, for injection number 2. They also went back in December for some blood draws, a process they'll repeat again this May, in an attempt to assess how well the vaccination (if they had one) stimulated their immune systems to fight COVID.

The Sandeens were instructed by their doctor to monitor the children for any subtle changes in behavior or mood in the 7 days after their two vaccinations, and take the kids' temperatures daily for at least a week. They were told to call the doctor immediately if the children spiked a fever, or had any other severe symptoms.

The parents were also given e-diaries for each of their children, a common protocol for vaccine studies like this. These diaries allow patients and caregivers to log any health issues that may pop up in the weeks and months after a vaccination, regardless of whether the parents think those issues may be vaccine-related or not. The Sandeens haven't have much of anything to report yet.

The Sandeen kids experienced no notable side effects, not even sore arms

"None of them had any kind of symptoms at all," Mr. Sandeen said.

"Nothing," in terms of side effects — no temperatures, no noted crankiness or changes in how the kids slept, no arm swelling or tenderness. The parents asked their toddlers frequently after their shots: are you tired? How are you feeling? Everything seemed totally normal.

"I think we're placebo," their dad speculated.

Their doctor, pediatrician Daniel Leonard, says that lack of side effects may be quite common in this age group — even among vaccinated kids. "I clinically couldn't have a hunch as to who got vaccinated and who didn't, because I wasn't having a bunch of side effects calling up my phone or showing up in e-diaries," Leonard said. Those younger immune systems are more "adept" and "ready to act," he said, and that may help explain why they've suffered fewer side effects than adults did.

Zander, the Sandeen's oldest, turned 5 recently, which meant that on his birthday (as he became newly-eligible for Pfizer's EUA vaccine for kids 5-11) his mom could call to find out if he'd had the real Moderna vaccine injected or not.

"I was in complete shock," his mom said. Zander was vaccinated after all, despite having no side effects.

His parents are now eagerly awaiting the day a COVID-19 vaccine is authorized for younger children, so they can learn the vaccine status of Zoey (now 4) and Lincoln (16 months old). If they find out that any of their kids got placebo shots, they'll rush to make them appointments for the real deal.

"Why would we want to leave our children unprotected?"

The Sandeens have never been part of a clinical trial before, but felt it was the right thing to do to better protect both their kids, and others around them, during the pandemic.

"I believe trials are very, very important, they're a very good thing," Mr. Sandeen said.

All vaccines that are authorized or approved for use in the US have to go through a process of clinical trials, which generally start in animals, then proceed to small groups of people, and finally end up in larger trials that include hundreds to thousands of willing participants. All those trial participants have to volunteer to be in the studies, fully understanding the potential risks, benefits, and unknowns of the vaccination. For COVID-19, vaccine trials from both Pfizer and Moderna have been conducted in an age-deescalation fashion, whereby the vaccines were trialed first in adults, before smaller doses were trialed in teens, then younger kids, and finally toddlers and babies.

"The FDA doesn't say, 'hey, look, we put something together, can we try it on you guys?' Mrs. Sandeen said, expressing her confidence in the scientific process.

Leonard says her sentiment is valid.

"The level of detail and the level of just scrupulous checks and rechecks to assure safety has been historic," he said of the COVID-19 trials.

Even so, the Sandeens did have some serious conversations as a couple about the benefits and risks of enrolling their children in the trial before they agreed to do it.

"Zach and I talked about it a lot," Mrs. Sandeen said. They thought about how their youngest, Lincoln, was born premature, and thus could be at greater risk from infections of all sorts.

Ultimately, for them, the risks of contracting a COVID infection, and the potential for long-term ramifications outweighed any potential risks of a new vaccine that had already been green-lit for use in a large-scale US trial.

"As parents, why would we want to leave our children unprotected against a virus that can cause long-term health issues?" she said.