Uganda, April 16 -- Some countries have paused the use of AstraZeneca vaccine due to suspected cases of blood clots and low platelet counts.
So far, no causal relationship between vaccination and the events reported has been determined. Risk factors specific to the suspected very rare adverse events have not been established. What has been reported largely is an association.
An adverse event following immunisation is considered very rare if it occurs among less than 0.01 per cent of the vaccinated persons. Because an event happened after vaccination (association) does not mean that it happened because of vaccination (causality).
Causality is a firm relationship between a cause and an effect, in which case the effect must precede the caus...