Kids, Infants & Long Term Impacts

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I wanted to start this post with a note of optimism. At times the last few weeks have seemed like nothing but bad news — vaccine roll-out is slow, variants are arriving and mutating, vaccines might not work perfectly, kids will not have vaccines until much later, and on and on.

But: I want to pause for a moment of optimism. Despite the slowdown, we actually ARE vaccinating a lot of people. Around 8% of the US has gotten at least one vaccine, and these are largely high risk people. We are seeing dramatically dropping COVID rates in nursing homes. Overall COVID case rates and hospitalization rates are dropping.

And while it’s true that vaccines do not seem to be as effective against some new variants, it’s not as if they provide no protection. There was a time when a 66% effective vaccine (this is the Johnson & Johnson vaccine performance against the South African variant) would have been embraced unequivocally. Yes, 95% is better and, yes, numbers like this likely mean we’ll need boosters going forward. But it is not nothing.

All this is to say that while there is lots to be worried about, and we cannot stop working to vaccinate faster and test more, there should be optimism too.

Now to the Content!

I wanted to address some of the many questions I’ve gotten on how to think about risk in kids. At this point, it’s been said many times that risks to kids are low. They’re low. Very low. Kids do not get very sick from COVID-19, and asymptomatic infection is common. This idea — that COVID is very rarely serious in children — underlies a lot of the possible return to normalcy. It will be a long time before kids are vaccinated, and if we want to do things like have normal school in the fall, or travel in the summer, we should expect to do it with unvaccinated kids.

But: When we report this out, people come back with (mostly) three questions. So I wanted to address them here.

  1. What do you mean low?

  2. What about infants?

  3. What about possible long term effects of even asymptomatic infection?

What do you mean “Low”?

As with all other groups, identifying case rates in children is a challenge. COVID-19 cases detected in kids tend to be rare, but this is in part due to relatively limited testing in this population (especially early in the pandemic). For this reason, I want to completely side step case rates and look at serious disease risk and mortality.

I’m aware that hospitalization and death rates are not by any means the only things we care about. But they provide a source of reliable data and they do proxy for less serious cases.

In the table below, I tried to pull out data from the CDC, along with some additional data from elsewhere, to both generate risks and providence context. All of these are effectively one year risks.

Let’s look first at COVID-19 itself. For a child between the ages of 1 and 17, the risk of death from COVID-19 is about 1 in 700,000 over this last year. The hospitalization risk is in the range of 1 in 50,000. For children under 1, the risks are slightly higher. A bit more context on this is below, but these numbers are still really small. COVID-19 accounts for only 0.2% of deaths among children under 1 year.

Numbers in this range are so small it can be hard to think about what they mean. Which is why comparisons are useful. The second two sets of columns look at two other sources of illness and death : RSV (respiratory syncytial virus, a common childhood respiratory virus) and drowning. For children under 1, the death rate from RSV in a typical year is three times higher than the death risk from COVID. The hospitalization rate is about 200 times as high. Put simply: in a typical year a child under 1 is 200 times as likely to be hospitalized for RSV than they were for COVID last year.

RSV is less common in older children; drowning is much more so. The death rate from unintentional drowning for children aged 1 to 4 is 20 times higher than from COVID-19; it’s about 7 times higher for older children. Hospitalization rates are similarly elevated.

I put this information up not to minimize COVID-19 (to be clear: the risk of death from COVID in the last year for someone over 85 is 1 in 50, which is extremely high). But the fact is that, for kids, serious illness risk is extremely low, far lower than risks associated with other common childhood diseases and injury causes. And at the same time I’m not trying to make you afraid of pools (although you should be very careful around them). Life entails some risk, whether acknowledged or not, and making good choices requires understanding this and, yes, accepting it.

What About Infants?

In the table above, you can see that infants (under the age of 1) are higher risk than older children. This is a little bit misleading, though, since they are generally higher risk for everything. In fact, COVID-19 accounts for a much smaller share of deaths in this group than in older children, even with the higher numbers. Put differently, illness risks are higher in babies than older kids so more caution is generally warranted, but not necessarily relatively more so with COVID-19.

A notable fact in the hospitalization data is that the rates seem to be highest in the very youngest infants (see here). Or, rather, infants under 2 months account for about 20% of total hospitalizations among children 0 to 17 (versus only 8% for infants 2 to 11 months). This could suggest higher risk in this group, or possibly that fever in very young infants often prompts hospitalization even without COVID to check for bacterial infection.

My read of this all together is that infants up to 2 months probably deserve even more caution than usual, and the excess risk of COVID-19 to older infants is similar to the excess risk to older kids. Which is to say, “low”.

(Read: maybe limit visits to young infants to people who are vaccinated.)

Long Term Effects

Expressions of this fear seem to come in two parts. The first is a fear that if your child does get sick from COVID-19, they may take a very long time to recover. The second is that even if they do not get sick, there are some hidden long term consequences that we will only learn about later.

To address the first. A small number of children do seem have persistent COVID symptoms, and we have seen cases of what is called MIS-C, basically serious post-COVID illness. The latter is rare, and the former is difficult to study. One recent paper reports on a cohort of 129 children in Italy, and suggests that 42% of them have persistent COVID symptoms even four months later. However: many many of these symptoms are non-specific and, more importantly, there is no control group. Runny nose and diarrhea are common even absent COVID. The data on fatigue shows 10.9% of kids report more fatigue after COVID-19, but 13.2% report less, suggesting this is likely just variation over time.

Based on what we know, it does seem likely that some children (like some adults) take a long time to recover from COVID-19. This is also true of other illnesses like the flu.

This is a known risk. I think more scary is the unknown risk that, somehow, even if your child doesn’t have symptoms of COVID, they will be harboring some kind of ticking time bomb that will cause serious issues later. This is not helped by articles like this one that 1000 people sent me on blood vessels. That article shows elevation of a particular biomarker in 50 hospitalized children who had COVID-19. The clinical significance of this is unclear, never mind the long term impacts.

This WSJ article does a good job, I think, making the scare case. To paraphrase: We know that in (for example) lung scans we see some evidence of infection even in asymptomatic people. We don’t know what it means, but it could be bad. Or not. But it could be bad. In kids, we do not have much evidence other than this blood marker study, but they could also have bad consequences. We really cannot know. Could be bad. Or not.

This evidence, especially in kids, is necessarily limited by what we simply cannot see. Eventually, we will have big studies which follow kids who had COVID and see if they have health problems. But this requires recruitment, testing, analysis and money. And, even with these, it’s going to be a long time before results. Like, literally, it could be decades depending on the outcomes you are worried about. Until then, uncertainty is basically our only option.

One possible conclusion is that you shouldn’t do anything until you can be 100% sure no one will get COVID-19. This is not, in fact, possible. Maybe you could wait until children vaccinated. But this ignores the possible costs of continued isolation on kids (and adults). These risks may also be long term.

My bottom line here is that this what-if-ism can go too far. We are always living with unknown risks. We should worry about the risks of COVID that we can see, just like we should think carefully about all the risks we face, and our kids face. But it’s not productive to get caught up in every fear about what could happen.

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