These vaccines are unlikely to completely sterilize a population

I would like to draw your attention to the fact that Professor Sir John Bell, professor of medicine at Oxford University, and a part of the GAVI team - Sir John is a member of SAGE (Scientific Advisory Group for Emergencies) and sits on the government’s vaccine task force that has negotiated the purchase of a handful of proposed vaccines to combat coronavirus - developing AstraZeneca's coronavirus vaccine, said in an interview with Jon Snow that "These vaccines are unlikely to completely sterilize a population. They are very likely to have an effect which works in a %, say 60 or 70%." Believe him, someone who has these levels of credentials doesn't misspeak without correcting himself.