>There is no precautionary case against the AstraZeneca vaccine<

..As an advocate for and expert on the Precautionary Principle, I should know..

by Rupert Read

The majority of the EU has now suspended the use of the AstraZeneca (‘Oxford’) vaccine, on ‘precautionary’ grounds. This makes no sense, for three reasons:

  1. Most importantly, there is no evidence that the ‘precautionary’ grounds cited are any evidence at all against this vaccine. There appears to be statistical illiteracy in the case assembled against the vaccine. One would expect plenty of blood clots to occur anyway in a huge population at any given time. This point is decisive. There is no reason, no evidence to believe that the AZ vaccine is not safe.
  2. But furthermore, even if point (1) were not decisive, and even if it turns out that evidence starts to emerge of some potential genuine concern re levels of blood clots correlated with this vaccine being given, then, if that level were low, there would still as yet be no valid precautionary case for suspending use of this vaccine. If and when one is in a non-emergency situation, then such precautionary considerations can be valid; because one has time to investigate them, and come forward in due course with a vaccine of whose safety one is in effect certain. A path is available, in a non-emergency situation, for avoiding risk. But we are not in a non-emergency situation. And so there might well be no such risk-free path available. We are in an emergency situation; for the prospect of a further wave of the virus at this point is very real, or indeed actual, including in some of the very countries (e.g. Italy) which have put the vaccine on hold. This wouldn’t be a problem if there were an endless swiftly-available supply of alternative vaccines, but of course that is not the case. In an emergency situation, triage is the primary consideration; precautionary considerations can’t be validly given, in such a situation, for non-use of an intervention that might have a cost but will help to prevent an exponential hazard. Exponential hazards outweigh non-exponential hazards in risk analysis. We need to be taking precautions to prevent further mass death from the virus; continuing to use the vaccine is in this sense precautionary, at the present time.
  3. It is true that there is a prima facie precautionary case always for slowness with vaccines (because of potential hidden exponential risks if there is a premature large-scale rollout), albeit a case that, as just explained, can be overridden. But, and moreover, what the invocation of precaution by some European governments as an alleged reason for pausing the Astra Zeneca jab neglects is that there is a equally a prima facie precautionary case, whether in an emergency situation or not, for rolling out vaccines, in order to establish a state of herd immunity. And this case is strong if an emergency is current; for, every day matters, not ‘just’ to save lives, but to race to achieve herd immunity prior to the potential emergence of deadlier or more transmissible variants of the virus. Bear in mind in particular that the more transmissible a variant, the higher the percentage of the population that need to be immunised, to achieve herd immunity and to open a possible pathway toward zero Covid. In short, this 3rd point means that there is on balance a strong precautionary case in favour of mass vaccination at the present time.

Finally, this 3rd reason why the invocation of ‘precaution’ cannot justify pausing the Astra vaccine suggests a manner in which the so-called ‘precaution’ being taken by European governments is anything but. If they lastingly undermine public faith in this vaccine, even by a few percent, that could make the difference between being able to attain herd immunity or not. And that could make the difference between us having a chance at eliminating the virus or not, or between a new worse variant emerging in a country with high cases in the coming month(s) or not. Their ‘precaution’ could be just what makes the pandemic worse, or endemic.

You will find no stauncher advocate of the Precautionary Principle than I. But the PP is persistently dogged by crude misinterpretations of it, that harm its cause. Given how vital that cause is, it is vital for defenders of the PP to stand up and be counted and explain when it is misused. This is a striking such case.

There is no valid precautionary case against the AstraZeneca vaccine. I’m off right now to have it myself…