Suppose the  rare but multiple deaths/injuries, by cerebral venous sinus thrombosis, have been caused by the AstraZeneca vaccine. Although my suspicions date to August 2020, a blog like this is in no position to establish causality. As with the Havana Sonic attacks, the determination of causality/reality requires national resources to acquire and analyze data.

Statistics needs mechanisms. If peculiarities of cases are not correctly weighted, the statistical  threshold, surpassing chance, could be missed. Mechanisms  focus statistics. (CNN) More European nations pause AstraZeneca vaccine use as blood clot reports investigated offers a possible mechanism.

The dilemma may recapitulate the yellow fever vaccine. It saves many lives, and takes a few. Over generations, inhabitants of regions where yellow fever is endemic  have learned the penalty, and correctly weigh the two risks. If COVID goes on long enough, we might arrive at the same understanding.

It is possible the AstraZeneca vaccine saves many lives and takes a few. The choice would be clear, except that the alternatives save many lives and take no lives, or far fewer. With the push of AstraZeneca, justified in the race against time, public health planners should be aware of the primitive logic people use to get by:

• Random risk. Ever present and possibly avoidable, “if I am careful”, “if I have no risk factors”, and so forth.
• Severe risk. For example, advanced cancer.
• Assumed risk. From a choice you make.

We are willing to assume just a little risk to minimize random risk. With severe risk, we are willing to assume considerably more, as with a bone marrow transplant. All the sophistication of the human brain permits just this simple weighing of pros and cons. COVID straddles the border of random and severe.

Unless strong counter-evidence emerges, as opposed to “no evidence”, that AstraZeneca is blameless of CVST, a blow back may result, playing into the hands of the antivaxers, in a highly disruptive way.

There are less fortunate places than the developed countries, where life is cheap and death is plentiful, where the inhabitants will be more appreciative of AstraZeneca.