Wednesday, December 15, 2021

Ignoring age and COVID risk is unscientific

I listened to a frustrating Sam Harris podcast about COVID policy yesterday. What struck me about these "expert" commentators was that they

  1. kept finding reasons to link COVID policy back to Trump, which was weird, and
  2. all but ignored the enormous age variation in COVID risk. 

Both these seem like popular ways of thinking, unfortunately. 

I want to comment briefly on the second issue. This should help explain why I support vaccinations for the elderly but feel strongly against vaccinating children, vaccine targets and mandates. 

The risk of serious illness or death with COVID is far more age-skewed than most viruses. In the below figure I show this skew. COVID is a serious disease for the elderly.

I also plot vaccine risks in the dashed orange. You might not be able to see it because it is so close to the axis. For age 70, the benefit-to-cost ratio of the vaccine is about 250x (i.e. the blue line is 250 times higher than the dashed orange line). A great outcome and something anyone would be foolish not to recommend. 

But exponential curves are deceiving. Let's zoom in on this curve for young age cohorts. I do this below (curve equation is 10^(-3.27 + 0.0524xage)). Notice now that we are way down near the vaccine risk. It's close. I show a broad range of risks and call this COVID curve the risk of serious illness. I do this because reality doesn't follow the neat equation I used to plot the curve and children are likely even lower risk than shown. 

In short, because the age skew of COVID risk is so severe, these huge many-hundred-times benefit-to-cost ratios can reverse at low ages so that the costs are many times the benefits. This is why so many doctors are calling for a halt to mandates for vaccinating children. 

We should let this well-known information about COVID guide us rather than politics and panic. 


  1. Where does your equation for the risk factors of Covid come from?

    Compare to the CDC page here:
    "There are approximately 28 million children between the ages of 5 and 11 years old in the United States, and there have been nearly 2 million cases of COVID-19 within this age group during the pandemic. COVID-19 can make children very sick and cause children to be hospitalized. In some situations, the complications from infection can lead to death."

    "As of mid-October 2021, children ages 5 through 11 years have experienced more than 8,300 COVID-19 related hospitalizations and nearly 100 deaths from COVID-19. In fact, COVID-19 ranks as one of the top 10 causes of death for children ages 5 through 11 years."

    From link 8300 / 2million give 0.4% hospitalization rate for children. The equation in the article is showing 100x less serious disease in this age group. Admittedly a large number of childrens covid cases will not have been officially reported, but surely more than 1 in 100.

    Also from the USA for approx 20million children 5-11 they have administered approx 6.5million first doses and 3million second doses. So far only about 14 or so incidences of serious side effects reported. Side effects more oommon after second dose(2-3x), many countries including Australia delaying second dose to reduce this downwards. Rates of side effects so far are far below teenage vaccine as it is reformulated at a lower dose and different buffer to be more stable at higher temps.

    Say after more data serious side effects rises to at least double say 40 per 10 million that is only 0.00004% not 0.04% as the graph shows

  2. Even if there is slight risk to younger people from the vaccine, the reason they should get the shots is to help protect the rest of the population. Otherwise, you leave a reservoir of infection to threaten older people.

  3. I don't think anyone is going to run a randomized control trial of 30,000 children with deliberate COVID infection on one side, and the vaccine on the other.


    Well on the vaccine side you might have 1 extra myocarditis case in hospital.

    On the covid side the hospitalizations would be two order of magnitude higher (100 times).

    Ethics would stop the trial.

    Can you imagine a trial where 100 kids end up in hospital, genuinely sick?

    How much diabetes would you cause?

    That seems to me what you are proposing at the population level.