As the NHS started rolling out the Pfizer/BioNTech vaccine, peer-reviewed results of phase three of the University of Oxford vaccine were published.

It is thought the data on the Oxford/AstraZeneca jab is the first set of Covid-19 vaccine data to undergo scientific peer review, and demonstrates efficacy and safety.

What this means is that various vaccines bought by the UK are at different stages along the approval and distribution process.

– What is happening with the Pfizer/BioNTech vaccine?

The jab has been approved for use by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), and on Tuesday a British grandmother became the first in the world to receive the jab outside a clinical trial.

Some 800,000 doses of the vaccine have been delivered to UK hospital hubs – enough for 400,000 people – but it is unclear when more doses will arrive from the manufacturer.

In total, the UK has ordered 40 million doses of the Pfizer jab, enough to vaccinate 20 million people as patients need to receive two doses.

– So has the Oxford vaccine been approved?

No. The MHRA is still looking at the data from the trials and is yet to make a decision on approval.

The regulator has been conducting a rolling review of the data from Oxford and AstraZeneca, and researchers hope the jab will be approved before the end of the year.

If approved, the UK has secured 100 million doses of the vaccine.

AstraZeneca said that it will be submitting data to regulators in the US, but its “base case assumption” is that the FDA will require the “read out” from the US arm of the trial.

– What have we learnt about the Oxford jab from the study published in The Lancet?

The paper backs up previous reports from the researchers on efficacy and safety.

No hospital admissions or severe disease have been reported in the vaccine group so far.

It also looks at whether the vaccine is capable of preventing transmission.

It is thought to be the first Covid-19 vaccine data to report on this, but the findings need to be confirmed when there is more data available from the trial.

There were 69 cases of asymptomatic Covid-19 disease identified in the UK study’s weekly Covid-19 testing of 6,638 people.

This included 29 out of 3,288 cases in the vaccine group, and 40 out of 3,350 cases in the control group, leading to a vaccine efficacy against asymptomatic transmission of 27%.

Isn’t there a third vaccine that UK regulators are looking at?

Yes. The MHRA is also conducting a rolling review of the Moderna vaccine.

The UK has secured seven million doses of the jab from the US firm – enough for around 3.5 million people in the UK – but these are not expected to be available until the spring.

Moderna has submitted for emergency use authorisation from the US Food and Drug Administration (FDA).

The European Medicines Agency (EMA) has also received an application for conditional marketing authorisation from Moderna.

– What do we know about the vaccines?

All three vaccines have reported efficacy results, showing varying levels of protection against symptomatic Covid-19 disease.

The Pfizer vaccine has been shown in studies to be 95% effective and works in all age groups.

Phase three trial results from Moderna suggest vaccine efficacy against the disease was 94.1%, and vaccine efficacy against severe Covid-19 was 100%.

Interim results of the Oxford vaccine trials found that the vaccine protects against symptomatic disease in 70% of cases – with vaccine efficacy of 62% for those given two full doses, and of 90% in those given a half then a full dose.

All three vaccines have not demonstrated any significant safety concerns so far.