Woke up to see this BBC graphic & claim doing the rounds. It's a great example of how data can come with a variety of biases & why perspectives on Covid vaccines is dramatically skewed in entire countries because of national/media bias. Here's why...1/n
https://twitter.com/kamleshkhunti/status/1383432829036417034
..First the claim about AZ being the cheapest: it's on the cheaper end, but it's not the cheapest.
There are 2 aspects to this: the costs of a dose & the costs of vaccinating. Eg vaccinating with a single dose is far cheaper; needing super-freezers is far more expensive...2/n
There are 2 aspects to this: the costs of a dose & the costs of vaccinating. Eg vaccinating with a single dose is far cheaper; needing super-freezers is far more expensive...2/n
...Out of vaxes on the BBC list, cheapest per person are Covaxin & CanSino (single dose).
J&J not far off AZ in real costs: manufactured in richer countries so doses more expensive, but it's one of several non-profit vaccines & it's a single dose ...3/n
absolutelymaybe.plos.org/2021/03/16/com…
J&J not far off AZ in real costs: manufactured in richer countries so doses more expensive, but it's one of several non-profit vaccines & it's a single dose ...3/n
absolutelymaybe.plos.org/2021/03/16/com…
...Back to the data viz. 2 things jump out: firstly, choice of metric - number of countries to claim global reach. What's wrong with that?
Firstly, it makes tiny countries equal with massive ones like China & the US - in population & land size.
...4/n
Firstly, it makes tiny countries equal with massive ones like China & the US - in population & land size.
...4/n
... Second, it's based on how many countries have authorized the vaccine - that doesn't take into account availability of doses on the ground.
It's not enough that a vaccine is legally available for use - what matters for perspective is how many doses are getting to people...5/n
It's not enough that a vaccine is legally available for use - what matters for perspective is how many doses are getting to people...5/n
...The next thing that's striking about this data viz is the data source is obviously flawed. That just jumped out dramatically for those bottom 4.
The skew in this dataset is clearly towards over-counting small richer countries & overlooking large lower-income countries ...6/n
The skew in this dataset is clearly towards over-counting small richer countries & overlooking large lower-income countries ...6/n
..Let's start with getting the chosen metric more accurate. First step, the same metric, comparing BBC with Wikipedia
Changes the perspective, but still has the problem of discounting large less-rich countries..7/n
BBC: ourworldindata.org/covid-vaccinat…
Wikipedia: en.wikipedia.org/wiki/List_of_C…
Changes the perspective, but still has the problem of discounting large less-rich countries..7/n
BBC: ourworldindata.org/covid-vaccinat…
Wikipedia: en.wikipedia.org/wiki/List_of_C…
...Next, a super rough way to make the point about the skew that comes from counting all countries equally.
Here's the same thing, but with Europe & the USA removed on the right.
(I classified Euro countries super quickly, so might be a little off)
...8/n
Here's the same thing, but with Europe & the USA removed on the right.
(I classified Euro countries super quickly, so might be a little off)
...8/n
...You have to keep in mind when you look at authorizations by country the knock-on effect in countries authorizing a vax as soon as WHO greenlights it: WHO has only done that for BNT-Pfizer, AZ, & J&J so far. This metric can shift quickly extranet.who.int/pqweb/sites/de… ...9/n
... So what about how the vaxes compare in actually being delivered? The world is reliant on each & every vaccine, because there's just too little. But who's getting what?
If you know of a great data source for this, let me know. I use multiple sources to get a view...10/n
If you know of a great data source for this, let me know. I use multiple sources to get a view...10/n
...Let's start with the same data source the BBC drew it's graphic from. They only have that data for 9 countries, so it doesn't help much. But it does show how strongly your perspective is skewed by which data you choose, doesn't it?...11/n
...So, what's the answer to the original question? Which vaccine has the greatest global reach?
Depends who you listen to. UK sources will tell you it's AstraZeneca, Russian will tell you it's Sputnik V, Chinese will tell you it's Chinese vaccines, &c &c ...12/n
Depends who you listen to. UK sources will tell you it's AstraZeneca, Russian will tell you it's Sputnik V, Chinese will tell you it's Chinese vaccines, &c &c ...12/n
...I think it's moving fast. Last year, it was clearly mostly Chinese vaccines. Now, the US has flooded the international picture with its massive local delivery of mRNA vaxes. Actual delivery is wildly different to original claims, with all sorts of reasons given...13/n
...Here's where WHO reckons the COVAX supply will come from - but that's only a proportion of what will be out there. For WHO, by the 2nd half of the year, AZ will be a critical chunk, but a minority. No one knows, though, what will actually happen. 14/14
https://twitter.com/hildabast/status/1370539338396700673
..PS inadvertent additional point!!! It's critical not to pick the wrong data file! When I saw the thread, a massive error of my own jumped out...🤦♀️🤦♀️ *This* is with Europe & the USA taken out. Sorry! 15/15
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