COVID Risks for Small Children

Happy December 27th! I hope you had a nice holiday weekend (if you celebrate) and are getting some rest if you can. I considered a newsletter break this week, but neither COVID nor parenting seems to be taking a break, so … here we go. Today’s newsletter is really for the parents of the 0-to-5 set, and especially for those of you who were gutted by the Pfizer announcement a week or so ago about the failure of the vaccine trials. To recap that situation: Pfizer has been running vaccine efficacy trials on two groups of children under 5 (6-to-24-month-olds and 2-to-5-year-olds). Last week, the company announced that the trials did not show enough immune response in the 2-to-5-year-old set after two doses. It plans to try a third dose, in the hopes that it will increase the immune response. There are a lot of unanswered questions, since not many details were provided, but the bottom line is that the trial failed and vaccines for this group are delayed. It is unclear precisely how much time we’ll have to wait. In addition to the Pfizer trial, Moderna is in a trial for this age group that now could be ready sooner. There may be other options. But those who hoped for a vaccine in January have had their hopes dashed. This has left parents a bit lost and feeling abandoned. It wasn’t necessarily helped last week by White House messaging about the unvaccinated facing “a winter of severe illness and death.” Even if we know they do not mean children under 5, it feels both scary and unfair. In fact, my sense is that there are two ways people are feeling, and it’s probably useful to separate them, which I’ll do below. First, people are angry about the continued life disruptions for small children and their parents. Second, people are worried about their kids. I want to focus mostly on the second today, with data, but let me comment on the anger briefly first. Disruption anger In the current setup, in at least some areas of the country, children in child-care settings are subject to significant quarantines for close contacts. One parent told me their child was out for a total of seven weeks this fall, all for quarantine (the child never got COVID-19). Another region mandates a 24-day quarantine for a parental breakthrough case (14 days from the end of the parent’s 10 days). This is untenable. Many parents were hoping for vaccines just to avoid this, since (at the moment) fully vaccinated students do not have a quarantine requirement. These policies cannot continue. When vaccines were a possibility for January, it may have felt like we could wait, but this is no longer true. The CDC or other public health authorities need to step in to limit quarantines, either by expanding test-to-stay protocols to child-care centers or simply recognizing that quarantine may be unnecessary. I’d make a similar argument about the general exclusion of children from the world. It is not reasonable, given the low risk to kids, to say that a 4-year-old cannot go to a museum or theater or restaurant because they cannot be vaccinated. There has been very little attention paid by the CDC and others to this group, and that must change. Parental advocacy has a role here, to be sure, although it is at least to some extent out of our individual control. Worries about child illness Many people looked forward to vaccines for kids under 5 in the hopes that the vaccines would protect them from getting COVID. In the 5-to-11 age group, infection rates (which were very low overall) were significantly decreased in the vaccinated group. With similar antibody response to vaccines in younger children, we could expect a similar reduction. The combination of the lack of vaccines and the presence of Omicron makes it more likely that, at some point in the next few months, children under 5 will get COVID. This is also true for children over 5, and for vaccinated adults. Omicron has shown a significant ability to infect even vaccinated and boosted individuals, although such infections are nearly always mild or asymptomatic. The vaccines are delivering significant protection from serious illness and death, and this prevention is increasingly the focus of policy. So when we think about younger children, I want to focus on this data: What are we seeing about serious illness in the under-5 set? I want to acknowledge that this discussion will focus on risks for otherwise healthy children. If you have a child with a serious comorbidity, it makes sense to talk through the degree to which their risk is elevated with their doctor. It will depend on the illness, and it also makes sense to consider in the context of other non-COVID disease risks. Within the U.S., the first place we look is the CDC data, which helpfully presents data by age group that separates out 0 to 4 from older children. I’ve put the current graph below. The 0-to-4 group is consistently among the groups with the lowest case rates, even though it is the least vaccinated group. The CDC also puts up hospitalization rates. In this case, I’ve filtered out the over-64 group, since it’s so much higher than the others that it is difficult to see the pediatric groups when it is included. The hospitalization rate for children 0 to 4 is consistently running around 1.6 per 100,000 in these data. This is higher than the 5-to-11 group but lower than all other groups. I will come back below to these numbers and what they mean. In addition to the CDC data, we have other data, mostly from Europe. We’ve seen very reassuring data from the U.K. on deaths (which are estimated at perhaps 2 per million); that was back in the summer. A recent study from Germany provides some new evidence. The paper, which is still in pre-print stage, looks comprehensively at the experience of children in Germany after COVID infection. The researchers are able to estimate the risk of hospitalization, ICU use, death, and post-COVID inflammatory syndrome (PIMS) by age group. It’s an impressive paper. I’m going to focus on the data for the under-5 group, although the study also looks at data for 5 to 11 and 12 to 17. For children under 5 without comorbidities, the authors estimate a risk of hospitalization of 84.5 in 10,000. That is: of 10,000 children who got COVID-19, they estimate that 84 or 85 of them would be hospitalized. They estimate that 12 of these children would need some type of COVID-19 therapy, and 1 would require ICU admission. They estimate a death risk of 0.1 in 10,000, or about 10 in 1 million cases. A further 4 children per 10,000 cases would receive a diagnosis of PIMS. These numbers are very small, whether you look at the U.S. numbers, the U.K. numbers, or the data from Germany. They tend to be slightly larger than similar numbers for children ages 5 to 11, but it’s hard to attribute that to something specific with COVID-19. The age group from 0 to 4 — especially from 0 to 1 — is at higher risk for hospitalization for virtually any illness (see this earlier newsletter for a discussion of babies). What’s hard about such small numbers is thinking about what they mean. Taken literally, this data says that if your child in this age group actually gets COVID, their risk of hospitalization at all is about 1 in 120. Only a small number of these children will need any COVID-specific therapy; the risk of needing it is about 1 in 840. How can we think about these numbers? Contextualizing risks It can be compared with what might happen if they got the flu or RSV. Based on CDC estimates, the RSV hospitalization risk for children under 6 months is around 1 in 50. For flu, for children 0 to 4 it is around 1 in 140. There are also non-respiratory comparisons. Based on data from the Netherlands and the U.S., the rate at which children in this age group are hospitalized for vomiting and diarrhea ranges from 1 in 100 to about 1 in 300 per year. Note that these are not rates conditional on being sick; these are just raw rates. In a given year, for a child under 5, there is a risk in the range of 1 in 200 that they will have to be hospitalized for these issues. Most of these will be minor, short-term hospitalizations; but the same is true for most COVID hospitalizations. Thinking about time Another way to conceptualize small probabilities is with time. Let’s say there was a 100% chance your child would get COVID-19 every single month. That is: every month they get COVID again, for sure. The risk of hospitalization is 1 in 120. This means that in 120 months of this — 10 years — you’d expect to go to the hospital once. Aaah! So many numbers! Here’s the bottom line: The risk associated with COVID-19 for children under 5 is comparable to, or somewhat lower than, many other common disease risks. Children under 5 are at higher risk for hospitalization from COVID-19 than children 5 to 11, in the same way they are at higher risk for hospitalization from virtually any other illness. Deaths are extremely, extremely rare — substantially lower than deaths from car accidents, birth defects, or cancer (among other causes). Children in this age group are also at much lower risk of serious COVID-19 complications than vaccinated adults, a point I have made before, others have made, and which I will not belabor. If you are comfortable with the serious illness risk that you yourself have, then your child is at a lower one. If your child does get COVID, you should expect it to look like one of the many other viral illnesses they get: fever, coughing, congestion. Possibly vomiting in some cases. It could be milder than that — a single day of fever, nothing else. What about long COVID? Many people are worried about long COVID: lingering unresolved symptoms. This has been an issue for some adults who had COVID. Generally, long COVID has seemed rare in children. Early data on lingering symptoms in the U.K. and Switzerland put the risks around 2%; these data were somewhat limited in their ability to have a comparison group. A comparison group is important, because many long-COVID symptoms are also symptoms of other things. Some children report a headache or fatigue on any given day, and without a comparison group it is hard to know if it is COVID or just kids. A new paper summarizes all the existing studies on this and comes to reassuring conclusions. These authors focus on 14 symptoms, reported to be persistent after COVID infection among kids, that were covered in data. When they limit it to papers with a comparison group, they find significant differences in only five of them, and these are small: a 5% increase in headache, 2% for sore eyes or throat, 3% for cognitive difficulties, and 8% for loss of smell. Moreover, all of these risks are larger in older children. Although the paper isn’t able to limit to the younger age set, this all suggests that long COVID is likely very limited in children under 5. Does Omicron change this? There is no strong reason to think so. There has been some discussion of increasing pediatric hospitalizations in New York City, but these are very small numbers. And, even there, the focus of the messaging is the need to vaccinate the 5-11 and 12-17 age groups. Omicron changes things in being more contagious; you, and your children, are more likely to get COVID. But this is different from severity. Summing up It’s important to be clear on what we cannot say. Low risk is not no risk. Some children — even very young children — have gotten very sick with COVID-19. A tiny number of them have died. This is tragic. We can also never say with certainty that there aren’t long-term risks to having had COVID-19. There is no reason to think there would be, based on everything else we know about respiratory diseases in children, but we cannot rule it out. What we can say is that based on everything we know, the risks to small children from COVID-19 are extremely small. The failure of the Pfizer vaccine trial was a blow to many parents. But given these small risks, it is not unreasonable to consider opening your life more, especially knowing that it will be months before vaccines are an option. This is a complicated moment for messaging. Within the past few weeks, the focus seems to have shifted significantly toward emphasizing preventing hospitalizations and deaths from COVID-19. President Biden himself noted that breakthrough infections will be common, and they will be largely asymptomatic or mild. The message about holidays was a version of: if you’re vaccinated, you’re at low risk of serious illness, so you can gather with family. The clear distinction between vaccinated and unvaccinated people is intended to encourage vaccination among unvaccinated adults, which I strongly support. But this messaging has caught in the crossfire kids under 5, who cannot be vaccinated but who, frankly, are at lower risk of serious illness than a large share of the vaccinated population. That doesn’t mean that we will not want to vaccinate children when we can! There will be value to doing so, including preventing spread to people vulnerable to breakthrough infections. But there is little value to instilling fear in parents by telling them their unvaccinated toddlers are facing a winter of death.

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