The first doses of the Covid-19 vaccine developed by the University of Oxford and AstraZeneca have been administered in the UK.

But what will this mean for the vaccine rollout, and how soon before those most at risk are vaccinated?

– What’s in the pipeline for the UK?

The Government has secured 100 million doses of the Oxford vaccine, enough for most of the population.

While some 530,000 doses are to be available from Monday, the Department of Health and Social Care (DHSC) said tens of millions more are to be delivered in the coming weeks and months once batches have been quality checked.

It comes almost a month after the rollout of the vaccine developed by Pfizer and BioNTech began, with more than one million people having now received their first dose.

Both vaccines require two doses.

– Why are people having to wait for a second dose?

The Medicines and Healthcare products Regulatory Agency (MHRA) has authorised two full doses of the Oxford vaccine, with the second dose given four to 12 weeks after the first.

It said data showed the vaccine was up to 80% effective when there was a three-month interval between the first and second doses.

A first dose of the jab gives around 70% effectiveness from three weeks after immunisation until a second dose at 12 weeks, according to the MHRA and the Joint Committee on Vaccination and Immunisation (JCVI).

Professor Wei Shen Lim, from the JCVI, said that people acquire a high level of protection after a first dose.

He said the JCVI therefore recommends that delivery of an initial dose should be prioritised for both the Pfizer and AstraZeneca vaccines.

– How will a vaccine be rolled out?

The Oxford vaccine can be stored at fridge temperature for at least six months so it is hoped that the logistics of administering it will be relatively straightforward.

Health Secretary Matt Hancock described the start of the rollout as a “pivotal moment”.

Jabs will be delivered at some 730 vaccination sites already established across the UK, with others opening this week to take the total to more than 1,000, according to the DHSC.

The vaccine will be administered at a small number of hospitals in England for the first few days, including the Oxford University Hospitals NHS Foundation Trust where it was developed.

Five other hospital trusts – two in London, and others in Sussex, Lancashire and Warwickshire – also started delivering the vaccine on Monday.

The bulk of supplies will then be sent to hundreds of GP-led services and care homes later in the week for wider rollout, according to DHSC.

– How quickly can people be vaccinated?

Professor Stephen Powis, national medical director of NHS England, has said the aim is to get two million people a week vaccinated.

The NHS will inform people when it is their turn to get the vaccine.

AstraZeneca said it was building up a manufacturing capacity of up to three billion doses worldwide next year, and aims to supply the UK with millions of doses in the first quarter in 2021.

Prime Minister Boris Johnson said the limiting factor in expanding the UK’s vaccine rollout was not supply or staff but waiting for batches to be approved.

He added that the capacity exists but that each batch needs to be properly approved and quality controlled

– Now there are more vaccines, does this mean a wider range of people can be vaccinated?

Not everyone at the top of the priority list created by the JCVI have been vaccinated yet.

So vaccinators will continue to work their way through the list.

Officials say the aim is to vaccinate all of those in phase one, representing some 30 million UK patients and health and social care workers, by the spring.

It is hoped more people in care homes will be reached with the rollout of the Oxford AstraZeneca vaccine.

The JCVI’s guidance says the order of priority should be:

1. Older adults in a care home and care home workers

2. All those who are 80 years of age and over and health and social care workers

3. All those who are 75 years of age and over

4. All those who are 70 years of age and over and clinically extremely vulnerable individuals, excluding pregnant women and those under 18 years of age

5. All those who are 65 years of age and over

6. Individuals aged 16 to 64 years with underlying health conditions

7. All those aged 60 and over

8. All those aged 55 and over

9. All those aged 50 and over

The JCVI is yet to set out details for the second phase of the vaccine rollout.

– Don’t vaccines take a long time to produce?

In the past it has taken years, sometimes decades, to produce a vaccine.

Traditionally, vaccine development includes various processes, including design and development stages followed by clinical trials – which in themselves need approval before they even begin.

But in the trials for a Covid-19 vaccine, things look slightly different. A process which usually takes years has been condensed to months.

While the early design and development stages look similar, the clinical trial phases overlap, instead of taking place sequentially.

And pharmaceutical firms have begun manufacturing before final approval has been granted – taking on the risk that they may be forced to scrap their work.

The new way of working means that regulators around the world can start to look at scientific data earlier than they traditionally would do.

– Is the Oxford vaccine being manufactured in the UK?

While there are some doses coming from Europe in the very first instance, the majority will be provided from the UK supply chain.

– Which jab is best?

The early vaccines all have high efficacy rates, but researchers say it is difficult to make direct comparisons because it is not yet known exactly what everyone is measuring in the trials.

– How many doses has the UK secured?

The UK has secured access to 100 million doses of the AstraZeneca/Oxford University vaccine.

It also belatedly struck a deal for seven million doses of the jab on offer from Moderna in the US.

Deals have also been struck for a number of other vaccine candidates which cover four different classes: adenoviral vaccines, mRNA vaccines, inactivated whole virus vaccines and protein adjuvant vaccines.

The UK has secured access to:

– 100 million doses of the Oxford vaccine

– 60 million doses of the Novavax vaccine

– Some 30 million doses from Janssen

– 40 million doses of the Pfizer/BioNTech vaccine – the first agreement the firms signed with any government

– 60 million doses of a vaccine being developed by Valneva

– 60 million doses of protein adjuvant vaccine from GlaxoSmithKline (GSK) and Sanofi Pasteur

– Seven million doses of the jab on offer from Moderna in the US.

– How do we know the vaccines are safe?

Researchers reported their trials do not suggest any significant safety concerns. Regulators, scientists and clinicians have also scrutinised the data.

– Will people get a choice about which vaccine they are given?

As things stand the vaccines will be rolled out as and when they become available.

People are not able to choose which jab they want to receive.

– Can the vaccines be mixed?

No. If you are given a dose of the Pfizer jab, your second dose must also be Pfizer.

The same goes for Oxford.

Clinical trials mixing different types of vaccines are planned but there is no data as of yet.

– When can social distancing end?

According to Prof Lim, social distancing measures and other protective measures such as wearing a face mask or hand washing are still needed.

“All those measures are still important at this point in time, even if somebody has received a vaccine,” he said.

“There are many considerations that go into deciding when social distancing measures and personal protective measures should be relaxed. Vaccination is one strand in our defence against the coronavirus.

“We need everything that we can do to protect ourselves and, at the appropriate time when we can see the vaccine having a true effect on severe disease and protecting people from dying, then perhaps we can start relaxing social distancing measures.”

– Can I have the vaccine if I am pregnant or breastfeeding?

Yes, where the potential benefits are thought to outweigh the risks. The MHRA recommends women discuss Covid-19 vaccinations with their doctor.