COVID-19 B.1.617.2 (delta) Variant, first detected in India, has contributed to a significant increase in the number of COVID cases and has inexorably spread all across the world.  The relative efficacy of BNT162b2 (Pfizer–BioNTech) and ChAdOx1 nCoV-19 (AstraZeneca) vaccines against this new variant was unclear Vaccine efficacy against the delta symptomatic infection vs. the predominant…