The ChAdOx1 COVID-19 vaccine jointly developed between AstraZeneca and the University of Oxford is not effective against the B.1.351 variant first identified in South Africa, according to a recent study published in NEJM. In a five-month study involving HIV-negative adults, 23 of 717 placebo recipients developed mild-to-moderate COVID-19 while 19 of 750 vaccine recipients did. Based […]