Covid vs. Flu for Kids

UPDATE: Faust has responded to some of the criticism of his original analysis. He has acknowledged the “good point” that he used multiple CoD for Covid vs underlying CoD for influenza. This was the key point in my criticism of his claims, however, in his “deeper dive” he still uses the larger number of Covid deaths repeatedly. (For example, he did not revise his claim that Covid killed around 600 children in 2021 down to 434 – instead he just added a caveat that it includes underlying or contributing causes.)

He also still has not addressed the different testing levels for influenza in the past versus Covid testing during the pandemic, nor has he addressed any of the other reasons why flu numbers may be undercounted via WONDER. He does spend considerable time in both blog posts disparaging anyone who doesn’t agree with him as a “Covid minimizer.” He also pretends to express gratitude for the “peer-review process” – yet he intentionally blocked replies to tweets with his initial flawed analysis, making it difficult to correspond with him with legitimate critique.

Recently, Jeremy Faust put out a blog post comparing monthly flu deaths to monthly Covid deaths titled “Delta and Omicron killed far more children than flu ever does.” The article was almost immediately shared by White House Covid Czar Dr. Ashish Jha and received widespread criticism from doctors and data analysts due to a dishonest comparison. Today, Bloomberg wrote an article parroting the talking points in the blog post with the click bait headline “Covid is Way More Lethal to Kids Than The Flu“.

I initially wrote a thread on Twitter explaining the issues with the analysis, and have expanded on the criticisms below.

Comparing Underlying vs. Multiple Cause of Death

For flu deaths, Faust uses deaths from CDC WONDER with the underlying cause of death listed as influenza on the death certificate (CDC says this “may drastically underrepresent” the flu burden). He doesn’t use flu burden estimates or the numbers for influenza & pneumonia combined. He argues that the flu burden estimates overstate flu deaths, which is certainly possible, but there’s still a reason the CDC uses these estimates instead of only relying on death certificates that specifically list flu as the underlying CoD (see explanation below).

For Covid deaths, Faust does not use the underlying cause of death numbers from CDC WONDER. Instead, he goes to a different data source. Faust uses Covid deaths from CDC’s NCHS where Covid is listed *anywhere* on the death certificate. Per CDC, for ~25% of these pediatric deaths, Covid is NOT the *underlying* cause of death. For January 2022, the difference is 103 with Covid as the underlying CoD vs 156 from NCHS. On the NCHS web site, the footnote states these numbers include, “Deaths with confirmed or presumed COVID-19, coded to ICD–10 code U07.1.” This is different than deaths from Covid, which is the language incorrectly used in Faust’s blog post and the Bloomberg article.

It is completely dishonest to compare multiple CoD data for Covid with underlying CoD data for flu, as several doctors pointed out in response to Faust’s “analysis.”

If Faust used the underlying cause of death data for both influenza and Covid, the graph would look like the one below. Note that the worst month of Omicron is very similar to the worst month of H1N1 for kids (October 2009). Faust also compares the mulitple CoD numbers for influenza and Covid, to further muddy the waters, but using underlying CoD numbers for both is more accurate and

Influenza Deaths are Undercounted vs Covid Deaths

Even if you adjust and compare underlying CoD for Covid vs Influenza as I did above, the comparison still has issues. As the CDC explains in the screenshot below:

  • many people are not tested for flu when they present for care (unlike Covid tests, which are given frequently, even to asymptomatic children)
  • when patients are tested for flu, the tests may be too late after infection or not sensitive enough to detect the influenza virus (unlike PCR testing commonly used for Covid testing)
  • many flu-related deaths occur due to secondary bacterial infections or by aggravating chronic illness

We test much, much more COVID than we ever did for flu, which further exacerbates the differences in metrics for these two diseases. This is why having an estimated flu burden is so important. It’s also why CDC groups influenza and pneumonia together in many places, because when someone presents with pneumonia, it may be too late or unnecessary to test for influenza at that point.

In addition, influenza deaths use a different definition than Covid deaths. The standard for recording an influenza death is markedly higher. Flu deaths require a confirmed laboratory test, while Covid deaths do not. They also require a “clinically compatible illness” that was was not followed by a full recovery to baseline health prior to death. These requirements are not true for Covid. For Covid, you are considered a confirmed case with zero clinical symptoms if you have a positive PCR test, and you are considered a probable case if you have symptoms and are related to another case (without any testing at all) OR if you have no symptoms and a positive antigen test. This makes it much more likely Covid will be recognized in many more cases where influenza would not be. You can argue that this means flu deaths are undercounted, or that Covid deaths are overcounted, but it’s hard to justify using these very different standards in a supposed apples to apples comparison of deaths from these two diseases.

After seeing the manipulation that the CDC is capable of over the past two years, I can certainly believe that the CDC has historically inflated the pediatric flu burden in order to increase uptake of influenza vaccination in children. However, you cannot ignore that there are several factors that cause documented flu deaths to underrepresent the pediatric mortality from influenza, especially as compared to how we have tracked pediatric mortality for Covid.

Overall Respiratory Disease Mortality

If we compare all respiratory deaths for children over the past several years, you couldn’t even identify there’s a pandemic virus.

Data from Other Countries

Furthermore, data from other countries doesn’t support the premise that Covid is more deadly to children than influenza. Many European countries have taken a much more reasoned approach to Covid, not requiring masking of young children ever, and limited masking of older children, re-opening schools much earlier and keeping them open, offering but not requiring childhood vaccination to participate in society, acknowledging unknown risks from vaccination that must be weighed against a child’s risk from Covid, etc.

Summary

It’s incredibly disheartening to see such flawed and misleading data being promoted by Dr. Faust, then Dr. Jha as the White House Covid Task Force leader, and then by Bloomberg without even any acknowledgement of the valid criticisms that were put forth.

As Dr. Munro, a pediatric infection disease doctor from the UK stated so succinctly stated about Faust’s analysis…