Research published today on the Oxford-AstraZeneca vaccine, which suggests that as well as preventing serious illness, the jab can reduce transmissibility of Covid by around two-thirds.
The University of Oxford published a report today which found a 67 per cent reduction in positive tests among those vaccinated.
The research also reveals that the vaccine efficacy is higher at longer prime-boost intervals, and that a single dose of the vaccine is 76% effective from 22- to up to 90-days post vaccination.
In this preprint, which is currently under review at The Lancet, they report on an analysis of additional data to include information from the trial up to the 7thDecember which includes a further 201 cases of primary symptomatic COVID-19 (332 cases from 131 reported in previously).
They report that the effect of dosing interval on efficacy is pronounced, with vaccine efficacy rising from 54.9% with an interval of less than six weeks to 82.4% when spaced 12 or more weeks apart.
Professor Andrew Pollard, Chief Investigator of the Oxford Vaccine Trial, and co-author, said:
‘These new data provide an important verification of the interim data that was used by more than 25 regulators including the MHRA and EMA to grant the vaccine emergency use authorisation.
‘It also supports the policy recommendation made by the Joint Committee on Vaccination and Immunisation (JCVI) for a 12-week prime-boost interval, as they look for the optimal approach to roll out, and reassures us that people are protected from 22 days after a single dose of the vaccine.’
Health Secretary Matt Hancock said:
“This is a hugely encouraging study and further reinforces our confidence that vaccines are capable of reducing transmission and protecting people from this awful disease. This report shows the Oxford vaccine works and works well.”