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The Science And Policy Behind The Decision To Vaccinate Younger Children


When will younger kids be eligible to get vaccinated against COVID-19? That's the big question with the school year already underway. In the U.S., the answer might be sometime in October, following news from Pfizer this week about positive results from its vaccine trial in 5- to 11-year-olds. At the moment, though, only a handful of countries are vaccinating children in this age group. Here to tell us more is NPR's Maria Godoy.

Hi, Maria.


FADEL: So what other countries have started vaccinating young children?

GODOY: Only a small number of countries are already vaccinating kids under 12. Cuba has started vaccinating kids as young as 2 with its own proprietary vaccine. Cambodia is giving shots to kids 6 and up, and China has approved two of its vaccines for use in kids as young as 3. Israel is vaccinating kids as young as 5 with the Pfizer vaccine but only if they have severe underlying health conditions. And Chile this month started mass vaccinations for 6- to 11-year-olds. It's using the Chinese-made Sinovac vaccine.

FADEL: So what do we know about how these vaccines in general are performing in kids?

GODOY: Well, there's a good sense of the safety profile of these vaccines. Let's look at Chile, for example. They're already moving ahead with Sinovac, even though the phase three trials, which really give you a big picture of safety and efficacy. They're just getting started. What we do know from earlier trials is that the vaccine is safe in children 3 and up and produces a strong immune response, although this was only in about 550 kids, which is not a lot. But I spoke with Dr. Miguel O'Ryan. He's a pediatric infectious disease specialist in Chile who advises the government on its vaccine strategy. He said Chilean officials were shown unpublished data that convinced them that the Sinovac vaccine was safe for kids this young. And Chile is running its own studies as it rolls the vaccine out to get more data on it.

FADEL: OK, so Chile is moving forward, and the U.S. may make a decision in a couple weeks. Are more countries likely to follow?

GODOY: You know, the big question other than safety is how effective are these vaccines in young kids? And we don't really know a lot about that yet. For example, Pfizer hasn't released data on whether any kids in the trial have gotten COVID, so we can't compare how often kids in the vaccinated group versus the placebo group get sick. So we don't know, for example - is it 90% effective at preventing infection? What we do know from data so far is that both Pfizer and Sinovac's vaccines elicit a strong immune response in kids akin to that in adults. We just don't have direct efficacy data yet. Given that uncertainty, Chile's Miguel O'Ryan says vaccinating younger kids isn't necessarily a clear-cut decision for countries at this time.

MIGUEL O'RYAN: You know, you can either wait for - have more data to support the strategy or move forward with that uncertainty if you have already covered the high-risk groups.

GODOY: And Chile has done that. More than 87% of its adults are fully vaccinated now.

FADEL: So we're talking about strategies for vaccinating kids under 12, meanwhile some countries are still deciding whether to vaccinate even older kids, right?

GODOY: Yeah. In the U.K. recently, a government advisory board actually recommended limiting vaccines for 12- to 15-year-olds to those with underlying health conditions. They just weren't convinced that the risk of potential side effects was worth the benefit, given the low risk of hospitalization and death for children, though some kids can get very sick and even die. But these advisers were actually overruled by government health officials, who thought minimizing disruptions to the school year was the stronger argument in favor of vaccinating kids 12 and up.

FADEL: NPR's Maria Godoy, thank you so much for your reporting.

GODOY: My pleasure. Transcript provided by NPR, Copyright NPR.

Maria Godoy is a senior science and health editor and correspondent with NPR News. Her reporting can be heard across NPR's news shows and podcasts. She is also one of the hosts of NPR's Life Kit.