Booster dose for COVID vaccination: Needed or Not?

It is well known that two doses of COVID vaccination – whether it is Pfizer, Moderna, AstraZeneca/Covishield or Covaxin – offer excellent protection against moderate and severe COVID (95-97%) but not against mild and asymptomatic disease (28%). Booster doses have been a matter of speculation since the early days of COVID vaccination when it was […]

AstraZeneca / Covishield vs Delta Variant, and Timing of 2nd dose of vaccine

The delta variant of SARS-COV2 is estimated to be 30-100% more transmissible than other prevalent variants and cause more severe infections than the original alpha-variant. At last count, it has spread to 80 countries and has rapidly become the dominant strain in several countries such as India and UK. Some concerns were expressed that the […]