An adenovirus vector vaccine against COVID-19 by CanSino Biologics
is projected to provide protection for two years if a booster shot is administered, said a scientist who played a key role in the vaccine’s development. The Chinese National Medical Products Administration
granted conditional market approval to the vaccine on Thursday. The vaccine, called Ad5-nCoV, has an efficacy rate of 65.7 per cent at preventing symptomatic cases and is 90.9 per cent effective in preventing severe disease with a single injection, according to an interim analysis of late-stage human trials released in February.