Coronavirus experts have warned lockdown could return due to new Covid variants saying the UK could end up in “the same situation we were in a year ago".

Scientists have said any future Covid-19 variants could bypass the immunity built up by people getting double-jabbed as the vaccine rollout continues to grow.

Experts are calling on the government to publish any plans for response should new variants of the virus start to overcome the protection offered by the vaccines.

The Scientific Advisory Group for Emergencies (Sage) have previously said the arrival of a new variant evading the vaccines is a “realistic possibility”, reports The Guardian.

Sage member Prof Graham Medley said: "A new variant that was able to overcome immunity significantly would be essentially a new virus.

“The advantage would be that we know we can generate vaccines against this virus – and relatively quickly. The disadvantage is that we would be back to the same situation we were in a year ago."

Dr Marc Baguelin, a member of the government’s SPI-M modelling group, said: "We would most likely be able to update the current vaccines to include the emerging strain.

“But doing so would take months and means that we might need to reimpose restrictions if there were a significant public health risk."

Changes to self-isolation rules 

The warning comes as changes to the self-isolation guidance introduced in England amid the coronavirus pandemic.

People who are fully vaccinated against Covid-19 will no longer have to isolate if they come into contact with someone who has tested positive for the virus.

From Monday, people in England who have had both doses of a coronavirus vaccine, or are under 18, will not have to spend 10 days in quarantine if they are a contact of a positive case, a change which has been hailed “another step back towards normality”.

They will be advised to take a PCR test, but that will not be compulsory and they will not have to self-isolate while they wait for the result.

The change came into effect in Wales on August 7 when instead of instructing fully-vaccinated adults to isolate, contact tracers and advisers started providing people with advice and guidance about how to protect themselves and stay safe.

In Scotland it is also already the case that double-vaccinated adults and all children can avoid self-isolation as a close contact so long as they are symptomless and provide a negative PCR test.

Health and Social Care Secretary Sajid Javid said: “The British public have played a vital role following self-isolation rules throughout the pandemic and sacrificing so much to help bring the virus under control.

“The requirement for double-jabbed and under-18s who are contacts of people with Covid-19 has been removed as we cautiously take another step back towards normality, thanks to the phenomenal success of our vaccine rollout.

“Vaccines are what will bring this pandemic to an end, with over 84,000 lives already saved and 23 million infections prevented.

“Please come forward to receive your jab as soon as you can to protect yourself and the people around you.”