1/ My column today - is "first dose first" (and worry about second doses later) the right vaccination strategy? https://www.ft.com/content/915756b2-6f13-41fb-9491-a647817aa919

2/ A couple of points. First, mainstream opinion on this has shifted in response to the new variants and rapid spread of infections. "First dose first" used to be the kind of thing only economists advocated. Now some (not all) virologists & immunologists are also on board.

3/ The bet is that single doses are more like driving with one headlight than cycling with one wheel. The data are limited but encouraging re: the efficacy of one dose in the short term. BUT BUT BUT

4/ We're often talking about very elderly people. Are we confident that a single dose will do the trick? (We don't know.)

5/ If we delay the second shot, will that ruin the booster effect? (Probably not. Might even help. But that's just an educated guess.)

6/ Will having single-shot people wandering around encourage "escape mutations" in the virus? Or will it actually reduce that risk, because there are fewer unvaccinated people? (We don't know.)

7/There are also worries about what this all means for public confidence in vaccines. I don't think we really know that, either.

8/ What we're missing are the new randomised trials that could give us more information - or even calling vaccinated people back for blood tests to see how their antibodies are doing. The UK has led the world with the RECOVERY trial of treatments. Why not vaccines too?

9/ I don't think there's anything wrong with making your best guess with limited information, particularly in a crisis situation. What DOES worry me is the prospect that this REMAINS a guess, because we're too busy to keep gathering vitally-needed evidence.

10/ PS "How To Vaccinate The World" Radio 4 Monday 11am will discuss this issue with @BeateKampmann @d_spiegel @VirusesImmunity .
@ATabarrok @florian_krammer @Daltmann10 @mgtmccartney and @IDEpiPhD are all worth following on this and other topics.

11/ PPS 11.30am not 11am. Soz.

12/ More on the idea of running experiments re the delay to second doses here, from @peterbachmd https://www.statnews.com/2021/01/04/stop-debating-first-shot-vs-set-aside-hospitals-should-compare-them/