Friday 5 February 2021 9:57 am

Covid-19 variants: could mutations prolong the pandemic?

The end is in sight. Isn’t it?

The cautious optimism of vaccination programmes made the final curtain of the Covid-19 pandemic visible for the first time.

Concern is growing, however, after Public Health England announced it is investigating cases with “worrying” new genetic changes found in regions of the UK.

Cases in Liverpool and Bristol sparked door-to-door testing earlier this week in a bid to stem the spread of newly emerging variants.

But how concerned should we be? Is the finish line still in sight?

The science

All viruses naturally mutate over time. Since Covid-19 was first identified a year ago, thousands of mutations have occurred.

Most of these have little impact but occasionally a virus changes in a way that helps it survive and reproduce.

What are these new variants?

  • A South African strain has settled in the UK. Tests show it has a mutation, called E484K, which could reduce vaccine effectiveness. Urgent testing is starting in parts of England where the variant is present
  • Scientists working with Public Health England have found several cases of the UK’s Kent variant with the E484K mutation
  • A UK strain first identified in the Southeast of England has become central to the spread of Covid-19. It is the UK’s most dominant strain
  • The government activated a widescale travel ban last month amid fears of a new Brazilian variant

How dangerous are they?

There is no firm evidence so far that coronavirus variants cause more severe disease, but there is concern that the NHS will be overwhelmed by a rapid rise in cases.

When viruses have an opportunity to mutate, they can easily spread and evolve.

Both the Kent variant and South African strain are thought to be more easily transmissible, sparking concern that they could cause a huge rise in cases.

The Prime Minister last month said there was “some evidence” that the Kent variant may be around a third more deadly than the original Covid strain.

Will vaccines still work?

Scientists are confident that vaccines will work against any new variants because they train the body to attack several parts of the virus.

The concern is that they won’t be as effective.

Research is emerging that appears to show the E484K mutation may help the virus evade antibodies in the immune system.

However, early results from Moderna suggest its vaccine still works against variants with this mutation, although the body’s immune system may not respond as strongly.

Two new vaccines, Novavax and Janssen, also appear to offer good protection, preventing serious illness.

If needs be, vaccines can be tweaked in a matter of weeks or months to better match mutations.

GlaxoSmithKline, Astrazeneca and Moderna have all announced they will create “a new generation” of vaccines specially suited to tackle emerging variants.

How serious is this?

The real issue here is the likelihood that new variants could be much easier to catch than earlier strains.

New versions have different spike proteins, the part of the virus which attaches to human cells, making them better at spreading and infecting cells.

The Kent and South African strains have more significant changes in the spike protein than the original UK variant, making its potential rate of infection problematic.

Scientists are concerned that variants may interfere with vaccine effectiveness, as its unique structure may help the virus evade antibodies.

Is there a silver lining?

Potentially. Variants appear to be mutating in a similar way rather than diverging from each other.

This gives scientists information about the virus’s favoured routes and allows them to work on ways to block those off.

The race is on to roll out vaccines as quickly as possible, to stay one step ahead of the virus.

What next?

More variants will emerge.

Controls will continue to be ramped up across the UK to monitor the movement of new strains and the government will act accordingly to protect the NHS.

The UK’s vaccine development minister Nadhim Zahawi has already announced measures to enable the production of another wave of vaccines if necessary.

Health secretary Matt Hancock told the House of Commons this week that the government was in touch with pharmaceutical companies to discuss whether tweaks were necessary at this stage.