Is the flu more deadly than COVID-19 for children?

Question

Dr. Jay Bhattacharya was quoted in this recent Foundation for Economic Education article:

In a debate last week with pro-lockdown Harvard epidemiologist, Marc Lipsitch, Dr. Bhattacharya acknowledged that COVID-19 “is an absolutely deadly disease for people who are older and for people who have certain chronic conditions.” He explained that there is a 95 percent COVID-19 survival rate for people 70 and older, while for people who are under 70, there is currently a 99.95 percent survival rate.

Dr. Bhattacharya said: “For children the flu is worse. We’ve had more flu deaths of children this year than Covid deaths.”

Dr. Bhattacharya who made the claim is also an important signee of the Great Barrington Declaration, which argues for focused protection, and which also states on the website that (without proof):

Fortunately, our understanding of the virus is growing. We know that vulnerability to death from COVID-19 is more than a thousand-fold higher in the old and infirm than the young. Indeed, for children, COVID-19 is less dangerous than many other harms, including influenza.

I know that Covid is hitting the older people disproportionately hard, but is it true that it hit less hard on children than flu?

Answer 1

True.

Says the WHO since March 2020:

Children are important drivers of influenza virus transmission in the community.

For COVID-19 virus, initial data indicates that children are less affected than adults and that clinical attack rates in the 0-19 age group are low. Further preliminary data from household transmission studies in China suggest that children are infected from adults, rather than vice versa.

While the range of symptoms for the two viruses is similar, the fraction with severe disease appears to be different. For COVID-19, data to date suggest that 80% of infections are mild or asymptomatic, 15% are severe infection, requiring oxygen and 5% are critical infections, requiring ventilation. These fractions of severe and critical infection would be higher than what is observed for influenza infection.

Those most at risk for severe influenza infection are children, pregnant women, elderly, those with underlying chronic medical conditions and those who are immunosuppressed. For COVID-19, our current understanding is that older age and underlying conditions increase the risk for severe infection.

And true, show the most up to date statistics from the CDC, if we concentrate on mortality:

_{— Deaths involving coronavirus disease 2019 (COVID-19), pneumonia, and influenza reported to NCHS by sex and age group. United States. Week ending 2/1/2020 to 11/7/2020. on: "Weekly Updates by Select Demographic and Geographic Characteristics. Provisional Death Counts for Coronavirus Disease 2019 (COVID-19)", cdc.org}

When comparing these numbers it should be noted: It is extremely remarkable that in 2020 influenza testing was as ever further increased, but the flu season was much lower than expected, with the southern hemisphere even skipping the flu season entirely:

Globally, despite continued or even increased testing for influenza in some countries, influenza activity remained at lower levels than expected for this time of the year. In the temperate zone of the northern hemisphere, influenza activity remained below inter-seasonal levels, though sporadic influenza detections were reported in some countries. In the temperate zones of the southern hemisphere, no influenza detections were reported across countries.
_{— WHO: Global Influenza Programme — Influenza update - 380 — 09 November 2020, based on data up to 25 October 2020}

Meaning the CDC table may show a somehow inflated number of covid deaths due to counting and reporting issues, but the also slightly imprecise numbers for influenza deaths are also much lower than usual currently.

Similarities: Both COVID-19 and flu illness can result in severe illness and complications. Those at highest risk include: Older adults, People with certain underlying medical conditions, Pregnant people,

Differences: The risk of complications for healthy children is higher for flu compared to COVID-19.

Influenza is dangerous for children but the current mortality rate for Covid in children is almost 0.0%.

Or, in the words of a trustworthy state public health agency:

Children are not considered to be at risk of serious illness Even if they have one of the conditions or illnesses that increase the risk for adults and older people, children are very unlikely to become seriously ill.

_{— Our World in Data: Mortality Risk of COVID-19}

But this may still change. While the above numbers still hold true for the vast majority of countries in Europe, for example Sweden and Germany, there appear some statistical outliers. While for influenza the attack rate in younger patients is generally much higher than for coronavirus, in influenza we also see the severity changing according to location, season and virus subtype.

For England – in this year – and note that the infinitesimally small number stats for children are within the group "<65"

COVID-19 mortality rates were higher than influenza and pneumonia rates for 2020 and the five-year average for all age groups in England

^{Age-standardised and age-specific mortality rates for deaths due to influenza and pneumonia, and COVID-19, England, occurring between 1 January and 31 August 2020 and registered by 5 September 2020}

_{- Deaths due to coronavirus (COVID-19) compared with deaths from influenza and pneumonia, England and Wales: deaths occurring between 1 January and 31 August 2020 Comparison of deaths from the coronavirus (COVID-19) with deaths from influenza (flu) and pneumonia. Includes deaths by date of death occurrence and breakdowns by sex and age.}

For New York City alone we see in a comparison for strong flu seasons and covid:

Notwithstanding the substantial burden of less severe infections due to both influenza and COVID-19 in different age groups, and the possibility that risk of death may vary over time, the higher age-specific mortality in the young in both the 1918–19 and 2009 influenza pandemics compared with COVID-19 is an important factor for decisions about whole-of-population versus age-targeted vaccination strategies.
_{— David J Muscatellod & Peter B McIntyred: "Comparing mortalities of the first wave of coronavirus disease 2019 (COVID-19) and of the 1918–19 winter pandemic influenza wave in the USA", Int J Epidemiol. 2020 Sep 15. doi: 10.1093/ije/dyaa186}

In summary:

• People <65 years old have 16–100 fold lower risk of COVID-19 deaths than older people.
• Age risk gradients are less steep in India and Mexico.
• Absolute risks of COVID-19 in the population are low for people <65 years old.
• COVID-19 deaths occur sparsely in people <65 without underlying conditions.

People <65 years old have very small risks of COVID-19 death even in pandemic epicenters and deaths for people <65 years without underlying predisposing conditions are remarkably uncommon. Strategies focusing specifically on protecting high-risk elderly individuals should be considered in managing the pandemic.

COVID-19 may thus be yet another disease with a profile dependent on inequalities and generating even more inequalities. The difference in the proportion of deaths in people <65 years old across different US locations may be due to chance, or may reflect genuine differences in the proportion of deaths occurring in nursing homes and/or the proportion of deaths occurring in younger populations of disadvantaged people, differences in reporting of COVID-19 deaths, or other unclear reasons.

Of interest, influenza deaths seem to have a similar difference in age distribution between the USA and European countries like Italy: a larger proportion of influenza deaths in the USA tend to be in the <65 age group (Estimated Influenza, 2018), as compared with Italy (Rosano et al., 2019). Of course, a major difference between influenza and COVID-19 is that the latter typically does not cause deaths in otherwise healthy children, in contrast to influenza (Wang et al., 2020b).
_{— John P.A. Ioannidis & Cathrine Axfors Despina G. Contopoulos-Ioannidis: "Population-level COVID-19 mortality risk for non-elderly individuals overall and for non-elderly individuals without underlying diseases in pandemic epicenters" Environmental Research, Volume 188, September 2020. doi}

Influenza is least dangerous for young adults, but more dangerous for children and elderly people.

Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. […] A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. _{— Wang et al.: "Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018: a systematic review and modelling study", Lancet Glob Health 2020; 8: February 20, 2020, doi.}

US Mortality (42 states and NYC reported):

Children were 0.00%-0.18% of all COVID-19 deaths, and 16 states reported zero child deaths

In states reporting, 0.00%-0.13% of all child COVID-19 cases resulted in death
_{— Children and COVID-19: State-Level Data Report, AAP Report Nov 2020}

While the CDC reports around 200 yearly influenza deaths in children with an estimate of 600 'true' cases due to underreporting (CDC Flu & Young Children), with actual data for 2020 still listed as insufficient:

_{— Influenza-Associated Pediatric Mortality, CDC FluView}

That is: for the start of the year we saw some pediatric influenza deaths (a 'record' of >170 for season 19/20) but for the season that just started now we have today:

"No influenza-associated pediatric deaths occurring during the 2020-2021 season have been reported."

That makes the other initial claim of 'more very young persons died so far from flu than from covid' true: while the 'everyone now has corona' season of 2020 so far within the age bracket of 0–24 had a reported death toll of covid deaths excluding inluenza (table 1) at 155, in the US the overall very mild flu season of 2019/20 took the lives as reported of finally in week 38 at 188 pediatric deaths (Compared for example to 2009 influenza-related pediatric deaths of even 317). Meaning a low prevalence influenza took more young lives in absolute numbers than the high prevalence corona outbreak. That well may change for the absolute numbers, since flu seems to remain at very low activity compared to corona which remains at a somewhat higher activity level. But the relative risk is unlikely to change: at similar virus activity the flu is more dangerous than corona for children.

Answer 2

Update 2021-03-24: Based on new data through "End Week" 3/13/2021:

the CDC tallied total COVID-19 death toll among children since the beginning of the pandemic (which has now had meaningful cases in the U.S. for almost precisely a year) is up to 273 (76 in 0-4 range, 197 in 5-18 range). By itself, this doesn't meaningfully change the original answer (273 still falls within the 37 to 600 range where we couldn't give a definitive answer without a head-to-head comparison), but:

1. It is higher than the officially reported pediatric death toll for any typical flu season (so if the rate of missed deaths was even remotely similar, more children died of COVID-19 this past year than in any typical flu season).
2. The same mitigation measures (or lack thereof) have now been in place during a flu season as well, so we have one cold/flu season in which both COVID-19 and the flu were operating, and both were subject to all the same mitigations aside from vaccines (no pediatric COVID-19 vaccine has been approved yet; they've barely started testing them).

With that in mind, the new comparison is:

1. COVID-19 killed 273 children in the U.S. this past year, 138 of them between early November (when the data from the original answer was pulled) and mid-March (current data at time of writing), a period encompassing the height of most flu seasons (the flu season typically extending a month further on either side, but with fewer deaths on either end).
2. The flu killed one child in the U.S during this past flu season (6-9 for the past year depending on whether you start from March or April, counting deaths from the tail of the previous flu season).

Even if we assume it was a low danger flu strain circulating this year (comparable to the one that only caused 37 pediatric deaths in a prior year), the anti-COVID-19 mitigations we made reduced the flu death toll by over 97% for this past flu season; even with inconsistent mitigations, the flu was effectively zero threat to children (the flu season basically didn't happen in either hemisphere this past year thanks to said mitigations), while COVID-19 remained a threat. So under the criteria of "which kills the most children under similar circumstances" the answer is clearly COVID-19. Even if the flu has a higher case fatality rate among children (there's no strong evidence on this either way, and it varies by strain), COVID-19 is clearly much more contagious; at any given time, your average currently uninfected child has a dramatically higher risk of dying of COVID-19 than the typical seasonal flu over the course of the following year, simply because they're far more likely to catch it, and it's lethal enough.

---

Original answer (still relevant for context and explanation):

"Is it true that it hit less hard on children than flu?"

Short answer up front: To the best of our knowledge, subject to the conditions we've been able to observe (vaccines for flu, lockdowns, distancing and masking for COVID-19), COVID-19 is, so far, a similar level of threat to children as typical seasonal flus; more deadly than some flu years, less deadly than others.

Long answer:

This is a hard question to answer definitively, since the death toll from the flu varies significantly from year to year. According to the CDC, the pediatric death toll from seasonal flu during the typical flu season has varied from 37 to 188 per year since 2004 (the 2009 H1N1 pandemic was an outlier, in that it had a total of 358 pediatric flu-related deaths between April 2009 to September 2010, a period of 18 months, and most of them occurred outside "typical" flu season). That said, the CDC is suspicious of the completeness of their pediatric flu death reports, and believes, based on statistical modeling, that the year with 188 deaths actually involved ~600 pediatric deaths.

If we focus on seasonal flu in general, we can say roughly, that if the annual pediatric COVID-19 death toll:

1. Is below 37, then COVID-19 is less dangerous than seasonal flus
2. Is between 37 and 600, then COVID-19, under existing mitigation strategies, may be less dangerous to children than some flu seasons, and probably more dangerous than others.
3. Is above 600, then COVID-19 is more dangerous to children than typical seasonal flus.

Note that this is not saying whether the child is more at risk once infected; that's much harder to determine (especially with the high rate of asymptomatic COVID-19 cases in children). If COVID-19 has a lower case fatality rate, but is sufficiently more infectious such that more children die of it, I'd argue it remains more of a threat to children than the flu for the same reason that we consider the flu a greater threat to U.S. children than we do Ebola; sure, many forms of Ebola are incredibly deadly if you catch it, but it doesn't spread easily enough to actually infect that many people under conditions in most developed countries.

Given those bounds, based on the CDC's raw data focused on deaths aged 0-18:

we can see that the United States has had 135 COVID-19 deaths in the 0-18 range (42 among the 0-4 group, 93 among the 5-18 group).

Thus, all we can say right now is what I said in the short answer:

To the best of our knowledge, subject to the conditions we've been able to observe, COVID-19 is, so far, of a similar level of threat to children as typical seasonal flus; more deadly than some, less deadly than others.

The qualifiers are needed because:

1. With lockdowns (including school closures), masking, and distancing, we're not observing COVID-19 as it would behave "naturally" (e.g. under the "focused protection" scenario proposed by your source).
2. Thanks to vaccines, we don't observe seasonal flus as they'd behave "naturally" either; approximately 80% of observed pediatric flu deaths occurred in unvaccinated or under-vaccinated (two shots are suggested the first year you receive a flu vaccine) children, even though unvaccinated children are in the minority.
3. We still haven't seen how COVID-19 behaves over the course of a full cold season (Fall-Winter), which we can expect to be worse than other seasons based on the typical behavior of coronaviruses.

Issue #3 should be answerable by sometime next Spring (looking at a full year's death toll during a period where COVID-19 was fairly widespread). But #1 and #2 are harder to account for.

Pediatric flu vaccination rates in the 2017-2018 flu season (when 188 pediatric flu deaths were reported, and 600 estimated) were 57.9% overall (higher for 6 mo.-4 y.o. groups, lower for teens), and given ~80% of deaths typically occur in the unvaccinated group, one could reasonably assume the flu would kill significantly more children if the vaccine did not exist. Beyond that, lack of a vaccine would increase the number of infected individuals spreading the flu, thereby increasing the number of cases, so it's not as simple as just applying the death rate from the unvaccinated group to the vaccinated group to estimate overall death toll, you'd have to guess at how much more community spread you'd see without the vaccine.

Similarly, while there is no vaccine for COVID-19, it does appear that mitigation (lockdowns, distancing, masking) reduced COVID-19 spread (and masking in particular appears to reduce severity as well), so it's nearly impossible to state with certainty how many more children would have died from COVID-19 if we'd just ignored it and gone about our lives.

Answer 3

It seems it might depend on the age sub-group, at least in France. Although data is so sparse that it comes down to a handful of actual deaths from either disease in adolescents, the number of deaths for Covid-19 beat that for influenza in that group in a statistically significant manner, at least in this comparison, which used the 2018-2019 flu season for comparison:

Of the patients hospitalised, the proportion of paediatric patients (<18 years) was smaller for COVID-19 than for influenza (1227 [1·4%] vs 8942 [19·5%]), but a larger proportion of patients younger than 5 years needed intensive care support for COVID-19 than for influenza (14 [2·3%] of 613 vs 65 [0·9%] of 6973).

In adolescents (11–17 years), the in-hospital mortality was ten-times higher for COVID-19 than for influenza (five [1·1% of 458 vs one [0·1%] of 804), and patients with COVID-19 were more frequently obese or overweight. [...]

In children, although the rate of hospitalisation for COVID-19 appears to be lower than for influenza, in-hospital mortality is higher; however, low patient numbers limit this finding.

I'm not sure why they didn't mention the other age groups in the abstract (perhaps the data is even more sparse, so not statistically significant as a difference--actually that's the case see table further below), but they do have this graph across age groups under 18, and it seems Covid-19 beat influenza in all of them for in-hospital mortality (2nd plot below) and for the ICU support fraction in the younger groups (1st plot):

They also give the raw number in an appendix, together with some statistical tests for the significance of the difference observed:

As seen in that table, the p-value for the difference is indeed not significant for the other children-age groups (except 11-17) with respect to mortality, but clearly there's a trend for Covid-19 being more deadly even in children under 11, if they are hospitalized with it.

Alas they don't mention how many children had been vaccinated against influenza, only that "influenza vaccination coverage against seasonal influenza in France was 29·7% for those under 65 years", which isn't too insightful for children in particular...

In the conclusion section they say

Although children seemed to have a lower risk of being hospitalised for COVID-19 (as shown here by the low rate of hospitalisation for COVID-19 compared with seasonal influenza in patients younger than 18 years), the in-hospital mortality of these children was more than four-times higher than it was for children with influenza.

I think by "children" they mean all under 18 in that para. To wit: there were 9 Covid-19 deaths among 1,227 cases in under 18 y.o. and 16 deaths among 8,942 cases of flu in the same age group. That gives 0.73% (hospitalized) CFR for Covid-19 in under 18 y.o. and 0.18% for flu. The ratio of these two percentages is approximately 4.

They do note that there's a potential source of uncertainty here because influenza testing isn't as widespread/standardized even in hospitals:

testing practices for influenza are likely to be highly variable across hospitals, whereas practices for COVID-19 may be more standardised (eg, all hospitalised patients require testing).

So if the CFR is narrowly defined for those hospitalized but we assume much higher attack rate of non-symptomatic or at least non-hospitalized children with Covid-19, it could be the case that the CFR is higher for Covid-19 than for flu even in children, but the IFR is not. At least in France. Unfortunately, the IFR is notoriously difficult to measure when there is a large fraction of asymptomatic presentations.

---

An editorial in the same journal issue points to another study with similar findings in Brazil (note the statistically significant difference in deaths--also this paper was on pediatric patient only, so they often drop the qualifier in the text)

The risk of death was comparable between the influenza and ORV group, but the SARS-CoV-2 group had more than three times the risk compared to the other two groups (adjusted OR=3.74 [CI 2.5-5.6], p<0.001) (Table 2).

The latter study has a somewhat similar disclaimer as to the relevance to broader/milder cases (which are not be hospitalized and may not be well accounted for):

We must emphasize that the clinical presentation and outcomes described in this study concern only a subset of pediatric COVID-19 patients: hospitalized children and adolescents with severe symptoms. Therefore, our results cannot be generalized to all children with COVID-19. Large population studies are needed to evaluate the broad impact of COVID-19 on children’s health.