Wednesday, February 24, 2021

Covid-19 updates

This is Joseph

I wanted to highlight two recent covid-19 articles. The first is about vaccine gloom and doom. There are many dangerous infectious diseases that have been banished by strong public vaccination programs. Here is a good example:

Measles. Has a 25% hospitalization rate and 1-2% case fatality rate (and not a lot of occult infection). That is pretty similar to the US case fatality rate for covid-19. The R0 reported for measles varies a lot (as we expect given how the context of R0 changes) but is pretty consistently reported as > 10 and commonly said to be between 12 and 18.  The MMR vaccine has similar efficacy for measles as the mRNA vaccines do for covid-19. There is some age dependence, which makes it hard to be sure of the actual effectiveness in practice, but it is not any different than ranges seen for different vaccines strategies for covid-19. The median R0 for covid-19 has been estimated as 5.7, which seems high but is a good scenario for comparing to measles. 

Do we fear measles enough to go into lockdown? I am not saying we can't learn from this and improve a lot of public health practice but I agree that it doesn't seem to match this message:

But the message from public health officials, the framing of it by the media, strikes me as bizarrely dour. It’s basically something like, “don’t expect to get anything like your normal life back for a very long time, because the vaccine isn’t a magic bullet.”

This is success. 

The second item I want to highlight is this article from Marginal Revolution looking at how early adopters are getting empirical data as to AZ vaccine effectiveness. It is a point that is getting old hat by now, but it involves the question of how fast to authorize vaccines that appear to work quite well. Matt Yglesias did a deep dive into this question and basically concluded that the impediments seem to be process and not anybody disbelieving that the vaccine would be effective. As the results from early adopters come in (see above), this only strengthens decisions by countries like denmark to try.

And this really gets to one of my main points: is this an emergency or isn't it? I think that it is, and that would suggest moving quickly to mitigate covid-19 infections. Vaccination was heralded as the tool of choice from the beginning -- why does Health Canada delay? The vaccine has been under rolling review since October of last year and as of today (Feb 23 is the date of authoring the post) it is still not an approved therapy. As of today, 2.4% of adults have been vaccinated in Manitoba. Compare that to Florida, with 6.9% fully vaccinated and 13.4% with 2 doses. Canada looks worse when you realize that Manitoba has 25,699 people with two doses and only 12, 572 with one dose. This is not picking on Manitoba, I will note that Nova Scotia lags behind them by quite a bit, as do Ontario and Newfoundland.  

I understand the need for safety and evaluation of therapies, but I wonder what is the concern that is slowing approval of vaccines once the phase 3 trials are completed? 


2 comments:

  1. I was born in 1941, so measles was part of my childhood. I don't believe the 25% hospitalization claim; it sure weren't like that when I was a boy.

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  2. «Measles. Has a 25% hospitalization rate and 1-2% case fatality rate (and not a lot of occult infection). That is pretty similar to the US case fatality rate for covid-19.»

    Those average between much higher rates for some categories and much lower rates for other categories. Also IIRC measles (or at least rubella) is really not good for pregnant women, for example.

    «And this really gets to one of my main points: is this an emergency or isn't it?»

    It is only for reaganista/thatcherite countries where the statement "the most terrifying phrase is 'I am from the government and I want to help you'".
    Those countries where governments are expected to solve public health problems with public projects the test-trace-isolate approach has resulted in minuscule death rates, a tiny loss of GDP, and no hurry to be vaccine mass testers.
    In the reaganista/thatcherite countries instead where "big government" is an evil and "big corporates" are wonderful, the approach has been to bet everything on the products of big corporates, with the media running huge PR campaign for the products of 2-3 selected transnationals (while there are over 200 vaccines in development), that have been praised as "saviours of humanity":

    https://assets.bwbx.io/images/users/iqjWHBFdfxIU/iYNfgM2zBOW8/v9/800x-1.jpg
    "Covid Vaccine: How Big Pharma Saved the World in 2020"
    "Miracle On Ice: So much went terribly wrong this year, and then the most loathed industry gave us vaccines and hope.”

    «I think that it is, and that would suggest moving quickly to mitigate covid-19 infections.»

    The difficulty with that is that vaccines need to be given to *everybody* including *healthy* people, so "first do no harm" is a very challenging hurdle. For example in the UK if a vaccine resulted in the death of just 2 people per thousand it would cause more deaths than CoViD-SARS-2 so far.

    The problem with mass vaccination is that there is a wide range of genetics out there, even if most variants are rare, and a vaccine that is quite safer for most may be quite bad for some, and that cannot be tested in advance.

    I think that it is still worth doing, as the chances when taking the vaccine seem to be better than with the virus, but caution and gradualism seem advisable anyhow.

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