@Vulpes vulpes

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.