The NHS is on standby to roll out a coronavirus vaccine from December, with people in the UK likely to be among the first in the world to receive the jab, the Health Secretary has said.

But Matt Hancock warned on Tuesday there were still many hurdles to overcome before the “vast task” of vaccination could begin.

Here is everything you need to know about the vaccine roll-out plans, what coronavirus jabs are in development and what the experts have to say.

– Who is developing the vaccine?

The two front-runners in the Covid-19 vaccine race are US pharmaceutical firm Pfizer, which is working with German biotech company BioNTech, and Oxford University, working with AstraZeneca.

Preliminary findings from Pfizer suggest its jab is more than 90% effective in preventing Covid-19.

Data on the Oxford vaccine, which is in phase three of clinical trials, is expected within weeks.

– When will the vaccines be ready?

Mr Hancock said it was “absolutely a possibility” that a coronavirus vaccine could be available by Christmas.

However, he said there were still various safety approval processes that the vaccines will need to go through before they can be rolled out in the UK.

Sir John Bell, who is part of the Oxford vaccine team, said he expects two or three jabs to be available by the new year.

– How long will the vaccine approval process take?

The UK’s medicines regulator could approve the Pfizer or Oxford jabs within days of a licence application being submitted, according to Mr Hancock.

He told BBC Radio 4’s Today programme that the Medicines and Healthcare products Regulatory Agency (MHRA) has been carrying out a rolling review of data from both Pfizer and AstraZeneca.

Mr Hancock said: “So that means that the regulator will be able to make a judgment on whether this is clinically safe, and not just take the company’s word for it, but do that within a matter of days from a formal licence application.”

– How will it be rolled out?

The UK Government has secured 40 million doses of the Pfizer/BioNTech vaccine, with about 10 million of these to arrive before the end of this year.

Mr Hancock said the military and NHS staff were on standby to roll out a vaccine across the UK from the start of December, and will work “seven days a week” to do so.

It will be delivered through care homes, GPs and pharmacists, as well as “go-to” vaccination centres set up in venues such as sports halls.

Mr Hancock said the UK will be among the first countries in the world able to do this.

– Are there any logistical issues?

Mr Hancock said Oxford’s vaccine was easier to deploy than Pfizer’s, which needs to be kept at a temperature of minus 70C and is being manufactured in Belgium.

He said that from the moment the Pfizer vaccine leaves the factory in Belgium it can only be taken out of minus 70C four times before it is injected into a patient’s arm.

While it will be a “mammoth logistical operation”, Mr Hancock said he had “confidence” it can be delivered.

– Is the vaccine safe?

All vaccines undergo rigorous testing and have oversight from experienced regulators.

Pfizer’s is known as a messenger RNA (mRNA) vaccine.

Conventional vaccines are produced using weakened forms of the virus, but mRNAs use only the virus’s genetic code.

They work by telling cells in the body to create antigens, which are recognised by the immune system and prepare it to fight coronavirus.

Some believe mRNA vaccines are safer for the patient as they do not rely on any element of the virus being injected into the body.

The vaccine has been tested on 43,500 people in six countries and no safety concerns have been raised.

– Who gets it first?

The Joint Committee on Vaccination and Immunisation (JCVI) has examined data on who suffers the worst outcomes from coronavirus and who is at highest risk of death.

Its interim guidance says that older adults in care homes and care home workers should get priority, followed by those aged 80 and over, and health and social care workers.

– What other vaccines are there?

There are more than 200 coronavirus vaccine candidates being tested around the world.

About 12 of them are in the final stages of testing, but Pfizer is the first to report any results.

Other potential vaccines in phase three trials include ones by US drugs firm Moderna and biotech company Novavax.

– Does this mean life will return to normal soon?

Mr Hancock told Sky News he was “not going to put a date on” when life may get back to normal.

However, Sir John Bell, regius professor of medicine at Oxford University and a member of the Government’s vaccine taskforce, said there was a chance of normality starting to resume after Easter provided “they don’t screw up the distribution of the vaccine”.

Meanwhile, David Nabarro, co-director of Imperial College London’s Institute of Global Health Innovation, said: “Even if a vaccine arrives in the near future we’ve got many months of still dealing with the virus as a constant threat that we’ve got to make certain that we continue to do all that is necessary to solve the virus causing major problems.”