Several Western governments rushed to offer support for the Oxford-AstraZeneca COVID-19 vaccination after South Africa halted its rollout when research showed it offered minimal protection against mild infection from a variant spreading there.The arrival of vaccines has given hope that scientists can tame a pandemic that has killed more than 2.3 million people worldwide. But if vaccines are less effective against new variants, they may need to be tweaked and people may need booster shots…https://www.cbc.ca/news/health/astra-zeneca-covid-19-vaccine-variant-concern-1.5905367
