Thread by @mark_toshner

Never make predictions. Especially about the future...

Here’s what will happen with vaccine clots reporting in next few weeks 1/n

1-2 weeks of loud noises about need for high safety bar. I’ve spent some time assessing causality of events for drugs- at least half of the reported cases will be complicated and best the European regulators will be able to say is 2/n

“Possibly related”. Even if a handful are more clear cut it is hellishly difficult to be definitive for individual cases so these will go into “probably” column. 3/n

Some may go into “not related” but even if they don’t it will make no difference because regulators will be left with a handful of cases either way. 4/n

Scientists will do maths and “risk” may increase from roughly 0.0002% for a rare thrombotic event for an individual to at very highest 0.002% or more realistically 0.0004%. Some might call this 2-10x risk but don’t be fooled by relative vs absolute risk. 5/n

2-4 weeks. Programmes will then be opened up again- how can they justify any other course of action vs a disease with a 1%+ mortality, 30% readmission rate and 25-50% persisting long term symptoms. 6/n

Regulators/scientists/politicians making these calls will now be on defensive again (see over 65s). They have sunk costs in justifying these actions. Public effect will be complete opposite of desired effect. Vaccines will go to waste, roll out will slow further. 7/n

4-6 weeks. Attempts to shift blame and they will try to move story back to lack of supply or to some nationalist or local political angle as this always plays well to someone. 8/n

Next cluster of rare things happens. Remember there are literally hundreds of rare things that can happen and they happen stochastically (at random). When we look for patterns, we see patterns (observer bias). What do they do now? 9/n

Having set the template twice (over 65s and now rare events), do they shut down again? Not doing so will be an admission they got it wrong last time (more sunk costs). Politicians not great at admitting mistakes (neither are scientists!). 10/n

At this point everybody is confused. Cases will be going back up. 8-12 weeks. New variants are now embedding but cavalry is arriving with updated vaccines. Safety needs established again and we are back to the start. 11/n

We need to break this cycle at some point. We need better international co-operation and to start listening to the WHO, the only organisation that can carry this. They are not perfect but they have been right on nearly all the big things and have clear vision on vaccines 12/n

We need better message discipline and communication. We are so distracted by this that we haven’t even started to put serious energy into developing countries with no vaccines yet. This is where the big battle lies.