One dose of Oxford Covid jab can 'reduce transmission of coronavirus by two thirds'

3 February 2021, 07:06 | Updated: 3 February 2021, 07:39

The Oxford/AstraZeneca vaccine could cut Covid-19 transmission rates by 67%
The Oxford/AstraZeneca vaccine could cut Covid-19 transmission rates by 67%. Picture: PA

By Kate Buck

The Oxford/AstraZeneca vaccine could cut Covid-19 transmission rates by 67%, in news which has been hailed by a leading pharmacologist as the "holy grail" of the global vaccine rollout

Preliminary results of a study conducted by researchers at the University of Oxford found the efficacy from two standard doses of the vaccine administered three months apart to be 82.4%.

Before these results, little was known about how effective the Covid-19 vaccines were at preventing transmission of the disease.

Read more: Oxford jab protects for 12 weeks after single dose, study suggests

The potential it could dramatically cut transmission after just one dose that will mean lockdown measures can be lifted sooner, a former chair at the Faculty of Pharmaceutical Medicine said.

Dr Gillies O'Bryan-Tear 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.

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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.

The potential it could dramatically cut transmission after just one dose that will mean lockdown measures can be lifted sooner
The potential it could dramatically cut transmission after just one dose that will mean lockdown measures can be lifted sooner. Picture: PA

But Dr O'Bryan-Tear warned that, as yet, there is little data to show how the researchers calculated the 67% 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."

Reacting to the news last night 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.

“More than 9.6 million people have already received the first dose of their Covid-19 vaccine and the NHS is working tirelessly to vaccinate as many people as possible in every part of the UK.”

Government data up to January 31 shows of the 9,790,576 jabs given in the UK so far, 9,296,367 were first doses - a rise of 319,038 on the previous day's figures.

Some 494,209 were second doses, an increase of 3,156 on figures released the previous day.

The seven-day rolling average of first doses given in the UK is now 388,971.

Based on the latest figures, an average of 407,402 first doses of vaccine would be needed each day in order to meet the Government's target of 15 million first doses by February 15.

However, the daily rate has been increasing ahead of the deadline in two weeks' time.

Data for January 30 showed 598,389 people were vaccinated in the UK.