but it is an interesting case study for those

looking to escape lockdown.

On the one hand, one of the most advanced vaccine programmes

in the world.

On the other, a new variant of coronavirus that's

infecting the population in record numbers.

Hopes now lie with the UK government's pledge

to offer a vaccine to 15m of the most vulnerable Britons

by the middle of February.

88 per cent of people currently dying from the virus

come from these groups.

With them protected it's thought that the rest of the population

should be able to enjoy more freedom without putting

the health services under too much strain.

That moment may come after the February half-term,

although we should remain extremely

cautious about the timetable ahead.

But whether the vaccination target will be met

and whether it will be enough to end lockdown

are two very different questions.

And a lot could happen between now and mid-February that would

change the outcome of both.

Here's what to look out for.

If the UK wants to vaccinate 15m people by mid-February it will

have to administer 2.5m doses per week for the next five

weeks.

At the moment, that figure is closer to 2.1m per week.

And Britain's health secretary has suggested delays

in scaling that up are down to the limited supply of vaccines.

The rate limiting step is the supply of vaccine.

And we're working with the companies

to increase the supply.

It's true that manufacturing is still getting up to speed.

And there are even shortages of the glass vials

that batches are transported in.

But bringing enough vaccination sites on stream

and hiring enough people to man them

is also presenting challenges.

The government has set up plans for 2,700 vaccination centres,

including hospitals, doctor surgeries, pharmacies, and up

to 15 mass vaccination sites.

At the same time the NHS has hired 80,000 professionals

to run the campaign.

But frustrations have mounted about how quickly the programme

is being set up, and policymakers are already

looking at other ways to accelerate uptake.

Right now, Israel is head and shoulders above other countries

when it comes to vaccinations per capita,

thanks in part to a highly centralised,

digital health system that makes it

easy to reach out to members of the public

and sign them up for a jab.

Britain has started to follow this lead

by sending out vaccination letters

from central government.

And in another attempt to speed things along,

Westminster has extended the gap between first and second doses,

although that strategy has its critics.

When Pfizer and BioNTech and Oxford AstraZeneca

completed their clinical trials they

recommended a three-week gap between first and second doses.

But now a growing number of scientists, including

the UK'S Joint Committee on Vaccination and Immunisation

and researchers at Oxford and AstraZeneca,

are recommending that the gap gets pushed much further

out to up to 12 weeks.

By extending the gap, we are going to,

over the next three months be able to essentially double

the number of people who can be vaccinated.

Hospitalisations and deaths from Covid-19

are currently at the highest they've ever been.

With more people receiving the limited protection offered

by the first dose quicker, the logic

is this strategy could take pressure

off Britain's overstretched health service.

And that, in turn, could offer a quicker path

to easing restrictions.

Even though some scientists are confident that extending

the gap between doses won't make the vaccine any less effective,

others aren't sure there's enough evidence about how much

immunity a single dose confers.

They've also warned that partially boosting

the immune system could create an opportunity for the virus

to mutate and become more resistant.

If that happens, all hopes of a swift exit from the crisis

will be dashed.

Thankfully, at the moment, there isn't evidence

that this is likely to happen.

The current UK lockdown is in large part

due to a new variant that emerged

in London and Kent called B117.

Early research suggests that neither this variant,

nor one originating in South Africa,

are likely to be more resistant to the current crop

of vaccines.

But experts have warned that we should

be prepared for many more variants

to emerge this year than last as the virus adapts

to its new human host.

If new variants evade both natural and vaccine-induced

immune responses the vaccines can be tweaked to catch up.

But analysts say this could take anywhere between one and nine

months, depending on what regulators demand.

The race between vaccines and the virus has a long way to go.

But the new variants that popped up last year

have given Covid-19 a head start.

Whether the UK hits its vaccination target

of 15m people by mid-February is hugely important

but not just for the sake of easing the lockdown here.

If vaccines don't catch up with the virus soon,

we could all find ourselves back on square one

with a new variant pulling far ahead.