Thread by @surplustakes

The US CDC is going to recommend that 'essential workers' are vaccinated before the over-65s, despite their *own modelling* showing this will result in more deaths.

Why? They say it is unethical to prioritise the elderly because they are not racially diverse enough. THREAD.

This is based on the slide pack below.

This takes for granted that healthcare workers will be first-in-line. The question is whether the next group should be other essential workers, the over-65s or adults with high-risk conditions.

cdc.gov/vaccines/acip/…

The authors do this by rating each group out of three for each of three metrics:
- Science (e.g. deaths and infections prevented)
- Implementation
- Ethics

First, Science.

The authors rely on modelling of the deaths prevented by prioritising each of the three groups, for both a "disease-blocking" and an "infection-blocking" vaccine scenario.

In both scenarios, vaccinating the over-65s is predicted to save the most lives.

In the disease-blocking scenario (which sounds more relevant to the Pfizer vaccine) more than twice as many deaths are saved by vaccinating the elderly first, compared to essential workers.

Despite this, the authors conclude that the "Differences among 3 strategies is minimal" (sic). Each strategy is thus awarded 3 out of 3 marks.

Implementation is considered easier for the elderly than the other two groups, resulting in the scores below:

So - with just Ethics to go - the over-65s are in the lead. Ethics is itself split into three sub-categories.

The key consideration (helpfully highlighted in red) seems to be that "Racial and ethnic minority groups [are] are under-represented among adults>=65"

Other considerations that seem important are:

i) adults with high-risk medical conditions must have been diagnosed which implies that they have access to healthcare (which counts against them)
ii) essential workers are unable to work from home

So in terms of Ethics, vaccinating essential workers first looks best, scoring the maximum in all sub-categories.

Now, note that the over-65s come in 2nd with 6 out of a possible 9 because...

This is translated to a mark of 1/3 in the overall assessment, meaning that Essential Workers pip the elderly to the post by one mark.

What drama!

So the recommendation that essential workers are next in line after healthcare workers.

I believe that the CDC is making a final decision this Sunday (though states have the final call).

This is the same CDC that comprehensively botched the initial stages of the pandemic.

This seems to me a clearly wrong decision and is out of line with what the UK, for example, is doing.

I am also sceptical of the modelling results given the vastly greater risks faced by the elderly (the below graph showing this is also from the report).

Incidentally, this report has many classic bureaucratic hallmarks:
- the spurious symmetry of three equally weighted categories, each with sub-categories
- the erratic marking thereof
- the artificial separation of "Ethics" and "Science"
- the opaque and questionable modelling

Bureaucracy is too important to be left to the bureaucrats.

cc @MWStory @zeynep @ATabarrok (anyone with interest in vaccine roll-outs and the US health bureaucracy)

Worth making clear that the views in the slide pack are not just those of the author.

The recommendation to prioritise "essential workers" was unanimously approved by the 14 voting members of the relevant CDC committee (ACIP).

The Director of the CDC, Dr. Robert Redfield, intervened a couple of weeks after the meeting to recommend greater priority was given to the over-70s. Good...

But only if they live in multi-generational households. Partly because such households are more diverse.

A reminder that states are perfectly capable of messing this up without the help of the CDC:

Nevada, New Hampshire and Wyoming are including cops in the very highest priority group, alongside healthcare workers.

apnews.com/article/health…

It's interesting to compare the UK approach.

As you can see below, there is no concept of an "essential worker" and healthcare workers are only in the second priority group along with the over-80s.

The fact that these groups cover 99% of Covid deaths reflects how age dominates almost all other risk factors.

Risk of death doubles with every ~7 years of age. Like all exponential processes, this is hard to get your head around. @d_spiegel on this:

bmj.com/content/370/bm…

This also explains the slightly lower priority given to those with underlying health conditions in the UK approach.

This table shows various conditions with increased risk of death in the region 1.25-4.27. This is bad but (very roughly) equivalent to only 2-15 years of aging.

A final note on QALYs (Quality Adjusted Life Years) which I see being brought up a lot. The CDC's analysis looks only at deaths prevented, not at QALYs preserved.

Could vax-ing younger groups make sense, based on the young having their whole lives ahead of them? I think no...

First, a back-of-the-envelope calculation. The 25-44s have around 5-10 times as many years remaining to them as the over-75s.

But, if infected, an over-75yo has a risk of death around 400 times higher than someone aged 25-44.

So, in terms of years of life saved, it seems it is around 20-40 times 'better' to vaccinate an over-75yo than someone 25-44. But this is a crude estimate and doesn't adjust for quality.

So we need to see some proper modelling. Thankfully this exists.

medrxiv.org/content/10.110…

This concludes that in QALY terms in it is best to vaccinate the oldest first.

It's still just about possible that looking at QALYs rather than deaths might have affected the results of the Science evaluation in the CDC report. But I doubt it.

I suspect is that the average age of those saved in each of the scenarios was very similar and that vaccinating "essential workers" mostly reduced deaths via reduced transmission to the elderly.

Clearly this whole area needs far more modelling attention and transparency.

https://twitter.com/surplustakes/status/1340312063470686211

UPDATE: as you all may now have seen, the CDC has seen the light & quietly shelved their previous recommendation and now support vaccinating >75s alongside a subset of 'essential workers'.

65-74s are a stage later, forming c. 1/5 of a huge lower priority group of 129m people.

This is a vast improvement over the previous plans, though still not optimal in my view. Still, compared to a pure "vax the old" approach like Germany or UK, should only delay the protection of the >75s by a couple of weeks.

It's worse for 65-74s, who still have an IFR of 2.4% and will have to wait many months to be vaccinated under these plans.

They will face very hard choices in the coming year.

mrc-bsu.cam.ac.uk/now-casting/

Many thanks to @mattyglesias @NateSilver538 and @DouthatNYT who arrived at similar conclusions independently and may well by their efforts have shifted the dial on this.

There's a chance a very foolish decision has been prevented by concerted action on social media.

It's now up to states.

There will be a vigorous state-by-state lobbying campaign by various companies and unions keen to crowbar their workers/members into the "frontline essential worker" category.

The more of these campaigns that succeed, the longer it will take to protect the elderly, both in the 65-74 and the >75 brackets.

If you live in the US, you need to be vigilant about what's happening in your state.

https://twitter.com/surplustakes/status/1340983279114182657