Younger kids can now get vaccinated. Let Andy Larsen tell you what the hard data shows.

After months of testing, we have a green light on vaccines for kids ages 5 to 11.

That’s come this week, after a meeting Tuesday, from the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP). There, the nation’s leading vaccination experts and pediatricians came together to discuss whether the benefits of vaccination for that age group outweigh the risks.

The short answer: They found that, yes, the pros were much bigger than the cons. A smaller Pfizer dose for children will be available by Monday at nearly all of the usual vaccination places: pharmacies, health department sites, clinics, and so on.

But I know our Salt Lake Tribune readers. They don’t want the short answer, especially not when it comes to their children’s health. So let’s go ahead and break down the data that the CDC panel used to make in its 14-0 vote to support vaccination in these youngsters.

The size of the current COVID problem in kids

As we know, 5- to 11-year-old kids make up the age group that is actually least at risk for severe illness from COVID-19. But just because a problem is smaller for this group doesn’t mean that it’s not a problem at all.

In sum, the CDC found that:

• There have been 1.9 million total confirmed cases of COVID-19 in this age group since the pandemic began. In mid-October, the last week of accurate U.S. data, kids ages 5 to 11 made up 10.6% of confirmed cases.

But for every one confirmed case, a CDC serology study estimated there was an estimated 5.2 additional cases that didn’t go reported — usually because the infected child didn’t get tested. Ultimately, officials estimated that, by September, 38% of 5- to 11-year-olds had been infected.

• There have been just over 8,300 hospitalizations of children in that age range since the pandemic began, roughly similar to the rate of hospitalizations found in a pre-pandemic flu season in this group. A third of those hospitalizations resulted in an intensive care unit visit.

• There were 66 deaths in the U.S. in the past year due to COVID-19 in these kids, which was the eighth-leading cause of death in the age group.

Interestingly, the ACIP compared the rate of COVID hospitalization and death for this group to hospitalization and death for other sicknesses it has recently recommended vaccines for, like the vaccines for hepatitis A, chickenpox, and so on. It found that COVID in this age group was generally found to be more likely to lead to death.

To me, these were important slides, because a statistic like “66 American 5- to 11-year-olds died last year due to COVID” is difficult to interpret. On one hand, every child death is a tragedy; on the other, there are a lot of kids in America. But to see that the impact of this disease in kids still outweighed the child danger of the diseases that are targeted by older, more familiar vaccinations put that statistic in more perspective.

How effective is the vaccine in kids?

So what kind of testing did the vaccine go through in this age group? Essentially, Pfizer initially got 2,268 kids to get a shot, which researchers split into two groups: 1,518 of whom got the vaccine, while 750 got a placebo. Months later, they got 2,379 more kids to get the shot, an additional group to raise the sample size in testing the safety of the the vaccine.

The dose they gave the children was 10 micrograms of the Pfizer vaccine, a third of the 30-microgram size of the normal dose they give everyone else. (Fun fact: The vials of the children’s dose come packaged with an orange lid, while the original dose comes with a purple lid, so that providers can differentiate.) Interestingly, they found that the 10-microgram dose was effective in producing more antibodies in kids than the larger dose was in the 16- to 25-year-old group in the original study. That makes some sense, though — kids have really effective immune systems.

In the end, the vaccine proved to be an estimated 90.7% effective: 16 cases of COVID happened in the smaller placebo group, while only three happened in the bigger vaccine group.

What about the side effects?

In short, Pfizer found that the side effects of the vaccine were likely to be even more mild in children than they are for young adults.

Here’s the slide presenting the side effects in kids ages 5 to 11 with the small dose compared to those ages 16 to 25 with the normal dose.

Fatigue, headache and muscle pain were the most common symptoms, though under 20% of kids reported those symptoms when compared to those who got the placebo. This isn’t listed on this slide, but it’s worth noting that 74% of kids felt pain in their arm after the injection of the vaccine, compared to 31% of kids who got the placebo.

In all of Pfizer’s groups in this age range, there were no cases of anaphylactic shock, myocarditis, Bell’s palsy, appendicitis or any other related “severe adverse events.” To give you an idea of the investigation that happens here, Pfizer reported that one of the kids in the trial suffered a “broken limb” — we’re not sure if it was an arm or a leg, but researchers investigated and found it was unrelated to the vaccine. (No, nobody seriously thinks that vaccines cause broken arms. At least, I hope they don’t.)

Myocarditis might be the most worried-about side effect of the vaccine in young people, so the CDC considered specifically in-depth evidence on that. In doing so, researchers investigated the 86 million doses that have been given to people under 30 years old in the U.S. so far, and found 829 cases of myocarditis among vaccinated people.

That is at rates higher than you’d normally expect, but they did find that 83% of those people had fully normal cardiograms three months later. Those who had vaccinated myocarditis had milder myocarditis than those who had it due to infections from viruses and bacteria. And while the CDC investigated nine deaths with potential myocarditis, it found zero deaths that could be confirmed due to the vaccine. Other infections or health issues were at play in those cases.

Naturally, for some parents the concern is this: How would a study find an unknown low-percentage risk in a study of only a few thousand kids? Essentially, it’s because the immune system of children between 5 and 11 and 12 and 17 are not wildly different. If there was a significant risk factor for the 11-year-olds, we almost certainly would have seen it in the millions of 12-year-olds who have been vaccinated so far.

What kind of an impact will immunizing these kids have on cases, hospitalizations and deaths?

Well, it depends how many kids get vaccinated, obviously. But we can put the impact in terms of millions of doses given to kids ages 5 to 11. This is what the ACIP estimates in terms of reduction, per million doses, in two scenarios: if the pandemic continues on its current trajectory or recedes to pandemic-average cases.

How many millions of doses should we expect? Well, the CDC also commissioned a survey to ask parents what they think about getting their kids vaccinated. They found that 35% of American parents said they would definitely get their 5- to 11-year-olds vaccinated; 22% said they probably would.

As you’d expect, that number widely changes depending on whether the parents were vaccinated themselves. Some 82% of vaccinated parents say they’ll get their 5- to 11-year-olds definitely or probably vaccinated, while just 1% of unvaccinated parents said they would.

Ultimately, the CDC estimated that approving the vaccine for this age group would result in approximately 600,000 fewer cases nationwide from November 2021 to March 2022. The CDC’s work group also noted that a reduction in cases of that size could result in more in-class teaching, more social interactions for children, and less work interruption for parents — but noted that these factors shouldn’t be included in the doctors’ decision on whether to approve the vaccine for children.

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In short, to decide whether to recommend giving the vaccine to 5- to 11-year-olds, the ACIP panelists did what a lot of people do when they’re making a hard decision: They made a pros and cons list. Yes, this one was more scientific and data-driven than most you’ll see scribbled in a yellow paper notepad, but it’s the same concept.

They found that the public health benefits outweighed the public health costs by a substantial margin — vaccination is good for the individual child and for the health of the community as a whole. Indeed, it wasn’t a close call, as the margins between the pros and the cons were even larger than most pediatric vaccines approved.

Andy Larsen is a data columnist for The Salt Lake Tribune. You can reach him at alarsen@sltrib.com.