Britain must keep Covid under wraps during the vaccine roll-out or it risks allowing the virus to mutate and render the jabs useless, an expert has warned.
Dr Christina Pagel, a health and mathematics researcher based at University College London, said allowing the virus to continue to spreading could give the coronavirus more time to mutate in a way that would make vaccines stop working.
The UK is already on high alert for mutations and today closed its borders to anyone who has not tested negative within 72 hours of travelling, to stop evolved variants coming in.
But there is still a risk that people will slip through the checks and that outbreaks will start again inside the country in the spring – vaccines minister Nadhim Zahawi has suggested lockdown rules could start to be lifted as soon as March.
If the virus can keep circulating it will keep mutating and, the longer this goes on for, the more likely it is that a devastating mutation will emerge. Scientists fear the virus could learn to evade vaccines over time.
England’s chief medical officer Professor Chris Whitty has already admitted that the UK’s current strategy of half-vaccinating people raises the risk of the virus mutating to become vaccine-resistant.
Dr Pagel said a combination of rapid vaccination and stringent ‘suppression’ of outbreaks should continue until the majority of people have been immunised.
The NHS’s vaccine programme has made impressive progress so far, with more than half of over-80s inoculated already and a total of 3,857,266 given jabs by Saturday.
Britain’s second wave was driven by a highly-infectious variant that first emerged in Kent.
Laboratory researchers have also spotted dozens of cases of a South African variant across the UK and last week confirmed 11 samples had tested positive for one of two Brazilian variants.
At least three major coronavirus variants have been spotted in Britain in recent months – from Kent, South Africa and Brazil – and they appear to be evolving to spread faster and to evade some parts of the immune system, although scientists do not yet think any have yet got so far as to slip past the vaccines completely
Dr Pagel, who is part of the Independent SAGE group, which has been highly critical of the Government’s pandemic response, told The Times: ‘We know that this virus does mutate and it mutates in ways that can potentially evade the vaccine.
‘Once we start vaccinating, we really want to vaccinate everybody before it starts to have the opportunity to mutate because then you’re much more protected…
‘What you don’t want is to get to September and suddenly you’ve got a new variant – whether we’ve imported it from somewhere else or we’ve grown our own variant – and then you’ve vaccinated 40million people and you have to start from scratch.
‘I just can’t imagine anything worse. So that’s why I think you actually want to go for suppression now.’
Preventing major mutations in the coronavirus is more important now than at other points of the pandemic because vaccines are coming into use.
Dr Christina Pagel, a member of Independent SAGE and a researcher at University College London, said: ‘What you don’t want is to get to September and suddenly you’ve got a new variant… and you have to start from scratch’
Even though it is considered unlikely, it is possible that the virus will be able to change so much that the vaccines – which are developed to produce immunity which targets a specific part of the virus when it looks a specific way – won’t work against them.
There is no sign that this has already happened but the virus only needs time to mutate – the more it circulates and the longer it is active for, the more mutations that emerge.
Viruses like the coronavirus mutate and change because of errors when they reproduce.
Each time the virus spreads it has to make copies of itself by forcing the body to read its genetic code and make a new version.
This happens so fast and so often that there are inevitably random errors and, although most of them make no difference, some can give the virus an advantage that makes it spread faster or for longer.
The viruses with these advantages tend to reproduce more successfully so pass on the mutations, allowing them to become widespread.
Dr Pagel warns that letting the virus spread too much during the vaccine roll-out will give it more opportunities to mutate.
Coronavirus cases in the UK have started tumbling in recent days as the effects of the third national lockdown set in.
There were 38,598 new positive tests confirmed yesterday, down from 54,940 the Sunday before.
And vaccines minister Nadhim Zahawi has suggested lockdown could start to be lifted soon after everyone over the age of 70 has been vaccinated – that phase of immunisations is starting today as it moves down from over-80s and NHS staff.
Mr Zahawi told BBC Breakfast: ‘If we take the mid-February target, two weeks after that you get your protection, pretty much, for the Pfizer/BioNTech, three weeks for the Oxford/AstraZeneca, you are protected.
‘One of the things we don’t know yet, and the deputy chief medical officer Jonathan Van-Tam is on record as saying “look give me a couple of months and I’ll tell you”, is the impact of the vaccine on transmission rates i.e. on infecting people.
‘So there are a number of caveats that stand in the way of us reopening the economy.
‘It will be gradually, it will be probably through the tiered system but you’re looking at that sort of period, two to three weeks after the middle of February, after we’ve protected the top four cohorts.’
He said there should be ‘very clear evidence’ by the second week in March that there had been a ‘break in the correlation between infection rates and hospitalisation and obviously death’.
‘But of course, there are a lot of unknowns, we don’t know the impact on transmission of the vaccines yet,’ he added.
As well as time and space giving the coronavirus opportunities to mutate, exposing it to people who have been half-vaccinated against it could allow it to evolve into a variant that is able to survive in the presence of a trained immune system.
Vaccines have been developed to create immune responses to specific parts of the virus – mostly on the spike proteins on its outer shell – and if these change too much they could become unrecognisable to the vaccine immunity.
Giving people half-doses of vaccines – which the UK is doing to stretch its limited supplies to cover more people – could expose the virus to low levels of the immune cells that are supposed to destroy it.
If this happens often and the viruses find they can get past the weak immune response, it could lead to a version of the virus that can keep spreading even in vaccinated people.
This is more likely under the current policy of giving people their vaccines 12 weeks apart rather than the recommended three weeks because more people will catch the virus between doses when they don’t have full protection.
Professor Chris Whitty admitted this month: ‘That is a real worry but quite a small real worry within the system.’
‘The general view was the size of the increase of the risk is sufficiently small that, measured against this ability to double the number of people who actually are vaccinated, the public health arguments are really strongly for doing what we have decided to do.’
He added: ‘Clearly, if we had infinite vaccine we might have taken different approaches, but we don’t.
‘At this point in time, for the next three to four months, the number of vaccines we have available is going to constrain our ability to get through the 25 to 30 million people we must do.
‘Whilst this is such a fast-moving virus at this time, our view was very strongly, on the balance of risk, the benefits to the UK for us at this point in the epidemic were in favour of doing this.’
The coronavirus is expected to mutate eventually in a way that will make vaccines less effective, but scientists aren’t yet sure when or how drastic this will be.
It could mean that people will be vaccinated every year, as with flu.
NHS England medical director, Professor Stephen Powis said that it was likely that there may need to be ‘frequent, maybe annual’ vaccination programmes to deal with new variants of Covid-19.
He told BBC Breakfast: ‘The early signs are that the vaccines will be perfectly adequate for that new strain.
‘Other strains of the virus will emerge – that’s what happens with viruses, they mutate.
‘Every year flu is a little bit different and we adapt our flu vaccines each year to cope with that.
‘I think it’s perfectly possible that over time the Covid vaccine will need to be adapted from year to year to deal with new strains.
‘The good news is that we’re using new technology with these new vaccines and that can be done very quickly.
‘So yes it is likely that there may have to be frequent, maybe annual – like flu vaccine programmes, which will deal with these new variants, but it’s a bit too early to be absolutely sure yet.’