> As of August 22, 2021, it is estimated that just over 80% of persons ≥12 years of age have received both doses of these mRNA vaccines. This appears to be the highest mRNA vaccine coverage worldwide ... Qatar has unusually young, diverse demographics, in that only 9% of its residents are ≥50 years of age, and 89% are expatriates from over 150 countries.
> ... BNT162b2-induced protection against infection appears to peak in the first five weeks after the second dose, but then gradually wanes month by month, before reaching diminished levels by the 20th week. Meanwhile, BNT162b2-induced protection against hospitalization and death appears to persist with hardly any waning for at least six months following the second dose.
The graph on page 25 reports that effectiveness of Pfizer against symptomatic infection falls to 0.0% after the 20th week.