A top scientist has said that the Oxford/AstraZeneca vaccine could prove to be the "holy grail" the world needs - after data showed it appears to cut transmission rates by two thirds.
This could lead to lockdown measures being lifted sooner than many dared to hope, according to Dr Gillies O'Bryan-Tear, former chair at the Faculty of Pharmaceutical Medicine.
It comes as preliminary results of a study by researchers at the University of Oxford found the efficacy from two standard doses of the vaccine administered three months apart is 82.4 per cent.
But it is the fact it also seems to dramatically cut transmission after just one dose that will mean lockdown measures can be lifted sooner, Dr O'Bryan-Tear said.
The scientist said the results, which have yet to be peer reviewed, were the first definitive estimate of the impact of vaccination on transmission rates.
"If the effect on transmission is confirmed for the Pfizer vaccine too, this would be a very positive," he said.
"If these vaccines reduce transmission to the extent reported, it will mean that the easing of social restrictions will be enabled sooner, than if we have to wait for herd immunity - which may never in fact be achieved because of insufficient vaccine population coverage."
He added: "That would be the holy grail of the global vaccine rollout, and these data bring us one step closer."
Senior public health officials have warned since the first vaccine was approved that there was no data to indicate what impact it would have on transmission rates.
If a vaccine only prevents a patient becoming severely ill, but they are still able to catch and pass on the virus, then everyone needs to have received a jab to be protected.
But if the vaccine also stops someone hosting and spreading the virus, then each vaccinated person also protects others.
But Dr O'Bryan-Tear warned that, as yet, there is little data to show how the researchers calculated the 67 per cent reduction in transmission in vaccinated participants compared to unvaccinated participants.
The paper is currently under review at the Lancet ahead of publication.
Dr O'Bryan-Tear said: "Few data were provided on how this figure was calculated, for example, how many samples it represented.
"We await fuller data and the publication, which will appear in the Lancet shortly."
