Elisabeth Mahase
BMJ, 2020
The Oxford and AstraZeneca covid-19 vaccine prevented some asymptomatic covid-19 infections in phase III trials, but the effect was mainly seen in the group who received a half dose first, followed by a full dose, the peer reviewed efficacy results have shown.1 The study, published in the Lancet , found that vaccine efficacy against asymptomatic transmission was 59% in the group that received a half dose followed by a standard dose (seven cases among 1120 participants versus 17 cases among 1127 participants in the control group), but just 4% in the group that received two standard doses (22 among 2168 participants versus 23 among 2223 for the control). The researchers said, however, that as this was a secondary outcome, additional confirmation was still required. Analysis of the primary outcome—efficacy against symptomatic cases of covid-19—showed that the vaccine was 62.1% effective in participants who received two standard doses (n=4440) and 90% effective in …
Cited by 3 publications.
Field of study: Medicine