BBCNEWS BBC News August 19, 2021 14:19:00
Here's our health correspondent. naomi grimley reports. for months, the office for national statistics and oxford university have been asking hundreds of thousands of us to do swabs for their research. do you have any symptoms? it's the biggest study of its kind in the world. unlike other studies, which have looked at how effective the vaccines are at keeping people out of hospital, this one has looked at how good they are at preventing any infection by the delta variant. the study showed the pfizerjab had 93% effectiveness two weeks after the second dose, compared to 72% for the astrazeneca v...