@MYTH@bubu :
 
 

Comme d’hab vous ne lisez pas les etudes que vous partagez.

Negative estimated effectiveness likely reflects an effect of bias and not true negative biological effectiveness. This bias may have risen from vaccinated persons having a higher social contact rate or adhering less to safety measures than unvaccinated persons31,32,33. With the high vaccine coverage among adults in Qatar (>85%)13, this bias may have also risen because the reference group of unvaccinated individuals included mainly children or young persons ; therefore, it may not be representative of the wider population.