A version of this article first appeared in Emily Oster’s newsletter, ParentData.
We thought it was the summer of fun. Camp! Popsicles! Followed by the fall of normalcy: back-to-school shopping, full school days, maybe even no masks. And now … the delta variant.
The vaccines we have remain highly effective against the delta variant. Yes, the efficacy numbers slightly lowered by the variant. But the vaccines are still very effective and extremely, extremely effective against serious illness and death. However: Kids under 12 are not eligible for vaccines yet. So, what about them?
When we turn to the question of kids, we need the right frame. Which is, to me: What, if anything, does this change?
We have been living with COVID-19 for more than a year now. We grappled with questions about how much to engage our kids in the world, how we wanted to mask, what case rates we wanted to respond to. At this point, for better or worse, you have probably made those choices.
When the delta variant is added into the equation, then, it would be a huge mistake to undo all this work. I think it’s easy to assume that the delta variant will require you to reevaluate everything. But you did so much work to make these decisions before— do not throw it away!
Instead, we want to simply ask whether the new variant should change what we do. The value of this frame is that it really narrows what we need to know.
There are two reasons that our behavior might change right now. One is if the delta variant makes kids more likely to get COVID-19. The other is if the delta variant is more likely to lead to serious illness in kids. Let’s deal with these in turn.
Is infection more likely?
The delta variant is more contagious; exactly how much is unclear, but it seems in the range of 60 percent to 100 percent more (100 percent more contagious = twice as contagious). This means that if an interaction with an infected person had a 10 percent chance of leading to infection with the original COVID-19, that same interaction has a 16 percent to 20 percent chance now.
This means that everyone—kids and adults—is more likely to be infected from a given interaction with an infected person. However, the data does not suggest a relatively greater degree of infectiousness for kids. That is, it doesn’t look like children’s increase in susceptibility with this variant is more than adults’. And remember, kids were not very susceptible to past variants of the coronavirus—which means even a doubly infectious virus does not leave them terribly vulnerable.
The best data we have on this is from the U.K., where frequent sequencing and the dominance of the delta variant for the past several months make it possible to look at the age patterns of infection. Just as in earlier phases of the pandemic, rates in younger children remain extremely low. (The most dramatic rise in infection rates over the past month is in people 16 to 24, a group that in the U.S. has been eligible for vaccination for several months, though even they are also still seeing a low percentage of positive tests, still under 1 percent.)
The group aged 2 to 11 is perhaps the most relevant here, in terms of parenting decisions, and the rates are low and flat even though there has been unmasked in-person school during this period. This should be reassuring.
It is important to note that over the next months we will continue, in the U.S., to see children be a larger and larger share of cases. (Not number, share.) This is because older people are largely vaccinated, and children under 12 aren’t. But that’s not because the variant is more infectious in children, it’s because infection is more likely for unvaccinated people.
Is infection more serious?
Serious infection or death from COVID-19 in kids is extremely rare. We know this, and it continues to be reinforced with data. Just this week, several studies out of the U.K. showed extremely low child death rates. Of almost half a million infections, there were 25 deaths, 15 of which were in children with serious underlying conditions. Any death is tragic, and death is not the only thing we are worried about, but this reinforces the conclusion that children are extremely low risk.
Turning to delta: There is disagreement about whether the delta variant leads to more severe disease in general. Some people have suggested it does, based on one study out of Scotland. Others have noted that there’s just not much data elsewhere backing up the idea that it leads to serious disease. However, this is generally a challenging question.
When it comes to kids, though, the data doesn’t point to anything that would look like alarming increases in hospitalization rates in recent weeks. Broadly, both cases and hospitalization rates have been declining in children in the U.S. over 2021. Delta has not been dominant here in this period, but the U.K. data also does not show significant hospitalization spikes over the past few weeks, either.
The bottom line is there is nothing in the data that we have so far that suggests the variant is more serious for kids. The situation is murky enough that it is hard to rule out the idea that it might be slightly more serious (partly, the risks are so low that you’d need a huge amount of data to figure this out, and with so few kids getting seriously ill, we just don’t have that). It also might be slightly less serious. But the fact remains that the risks of serious illness for kids remain really, really low.
(Yes, many people are worried about long COVID. But, again, this is a risk you thought about before. If the risk of contracting COVID rises slightly, so would the risk of long COVID, but, again, you don’t need to start from scratch and throw out all your previous decisions.)
So, what does this all mean? Should you do anything differently?
I revisited my calculator as a window to what changed. (You can download a copy of the calculator to use it to estimate your own risks—read more about how it works here.) First: The presence of the variants may mean that case rates go up, especially if you are in an area with limited vaccinations. So you will want to watch those—independent of the variants, they’re an important metric to keep an eye on, to adjust your choices accordingly. The New York Times tracker can show you rates in your state or county.
Second: The more contagious virus warrants an update of the transmission risk, which I did in the calculator, changing it from 12 percent to 20.
More generally, let’s say you thought through some case rate cutoff for various activities before the delta variant was in the picture. Like, maybe you thought, I’m comfortable with my child in day care as long as daily case rates are below 60 in 100,000. The presence of the variant should reduce that threshold proportionality, since it’s based on an assumption about transmission risk. If the variant is twice as contagious, your new threshold should be 30 in 100,000.
And if an activity is extremely low risk—like being outside, even unmasked—this shouldn’t change what you do. Twice a close-to-zero risk is still close to zero.
In this way, you can use the decisions you made before. Don’t force yourself to remake them all.
And remember that reasonable people have disagreed on risk tolerance and kids throughout the pandemic. If someone doesn’t want to do a certain activity because of rising cases and delta—that might be a fair calculation for them to make.