The problem is that we had put quite a few of our eggs in the AZ basket to begin with, so the loss of confidence seriously delayed our vaccine rollout. And in t

The problem is that we had put quite a few of our eggs in the AZ basket to begin with, so the loss of confidence seriously delayed our vaccine rollout. And in the end we missed out, by a couple of months, on having good vaccine coverage before the delta strain got away from us. On the other hand, I think some of the anti-anti-AZ stuff is over the top. The increased TTS risk is by now clearly real, the non-fatal outcomes are often pretty bad, and until recently the fatality rate was expected to be very high. In the pre-delta period, when our covid prevalence was extremely low and it was reasonable to hope that state would last long enough to see us through to the Pfizer rollout, waiting for Pfizer was probably a sensible decision ex ante for many people, even taking into account a reasonable level of pro-sociality (and even without knowing that there would be a significant difference in effectiveness). An official or media-led decision to play down the risk would have caused some preventable deaths (and serious harm to a larger number) among people who, from a self-interested perspective, probably shouldn't have taken that vaccine in the first place. With hindsight, those deaths are outweighed by the covid deaths we're now seeing; but that wasn't obvious pre-delta, and in any case the authorities would have burned a lot of trust and given a free kick to the 'sceptics' and conspiracy theorists if they had hidden or misleadingly played down the risk.