Pfizer claims 3rd dose 'strongly' boosts protection against Delta variant https://t.co/6idBBhpT63 pic.twitter.com/rTRBIctOie— CTV News (@CTVNews) July 28, 2021
Pfizer claims 3rd dose 'strongly' boosts protection against Delta variant https://t.co/6idBBhpT63 pic.twitter.com/rTRBIctOie
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