Read on Twitter
In a thread yesterday, I lapsed into the unhelpful shorthand of "one-dose" vs. "two-dose" plans for vaccine rollout.
*Everyone* I know wants to vaccinate every willing American twice.
So I'd suggest as better terms "breadth-first" vs. "depth-first." https://twitter.com/CT_Bergstrom/status/1345205648854716416
*Everyone* I know wants to vaccinate every willing American twice.
So I'd suggest as better terms "breadth-first" vs. "depth-first." https://twitter.com/CT_Bergstrom/status/1345205648854716416
The original plans were depth-first: vaccinate people in the highest risk tiers twice, and move on down the line.
The breadth-first idea is if one dose is better than half as good as two, we could slow the pandemic by getting get vaccines into as many people as possible first.
The breadth-first idea is if one dose is better than half as good as two, we could slow the pandemic by getting get vaccines into as many people as possible first.
So with breadth first approaches, we would try for broad single-dose coverage and then circle back around, so to speak, for second doses. This might be e.g. 12 weeks after the first dose.
I lean depth-first, but I'm not certain which is the right approach and it's gnawing at me.
I lean depth-first, but I'm not certain which is the right approach and it's gnawing at me.
Let me list two of my big concerns with the breadth-first approach.
The first is logistics. We can say we'll come around with second doses in 12 weeks — but we don't have a good track record here. I fear that promise will go the way of 100M by Jan 1, and then 20M by Jan 1.
The first is logistics. We can say we'll come around with second doses in 12 weeks — but we don't have a good track record here. I fear that promise will go the way of 100M by Jan 1, and then 20M by Jan 1.
The second is public confidence. The original plan was framed as depth-first, and changing that could be quite harmful. Organized antivax propaganda is everywhere, and changing strategies mid-rollout does present an impression that the whole processes is somewhat haphazard.
There are other lesser or more subtle issues at play as well. I was personally worried about second dose uptake even with a depth-first approach. A breadth-first approach could be misinterpreted as tacit acknowledgment that the second does is unimportant.
And then there are what I believe to be largely non-issues. Lots written on twitter recently about breadth-first approaches selecting for vaccine resistance / escape variants. It's a complex subject, but in short I don't buy it. Vaccines aren't antibiotics; that analogy misleads.
