The first UK cases of the omicron Covid variant were also confirmed on Saturday, with two people, in Essex and Nottinghamshire, testing positive for the variant. Officials have since started carrying out mass testing in affected areas to identify further cases.

Prime Minister Boris Johnson announced on Nov 27 that new restrictions would be imposed in response to the cases in a bid to slow the omicron variant.

Mr Johnson said that, from Nov 30 people must wear masks in shops and on public transport. Anyone who enters the UK must now also take a PCR test by the end of the second day after arrival and self-isolate until they have a negative result.

Variant has 50 mutations 

The variant has about 50 mutations, with 30 in the spike protein and 10 in the receptor binding motif, the part that binds to our cell receptor called ACE2, which is greater than any other mutated strain.

Spike proteins are little grappling hooks on the surface of the virus which it uses to latch on to human cells.

Changes to the spike protein are particularly concerning because vaccines have been designed to help the body recognise the spike shape. If they change too much, the immune system will be blind to an infection. 

Put simply, vaccines would stop working and all our hard won protection would be lost.

Antibodies made by the body from a natural infection may also struggle to see off this new interloper.

There are also mutations at the furin cleavage site, which is alarming as this is an area that helps the virus get into human cells, and which makes it so infectious.

One mutation, P681H, has previously been found in alpha, mu and some gamma cases. But this is the first time that two changes have been seen in a single variant.

These changes are likely to enhance the virus’s ability to enter cells, increasing viral load and making it more transmissible.

There are also two mutations in an area called the nucleocapsid, R203K and G204R, which were present in the alpha, gamma and lambda variants, and are known to increase infectivity.

As if this were not enough, there are also several changes that have never been seen before, which are also alarming scientists.

‘More of a hit on vaccines than anything we’ve seen so far’

Dr Jesse Bloom, a virologist at the Fred Hutchinson Cancer Research Centre in Seattle, said that many mutations, particularly E484, G446, K417 and Q493, were at “peak escape sites”, meaning that many antibodies would be impacted.

“This does not mean that the [omicron] variant will fully escape vaccine or infection-elicited antibodies. It takes many many mutations to fully escape neutralisation, and there are also T-cells,” he said.

“But I’d expect the [omicron] variant to cause more of a hit on vaccines – and infection-elicited antibody neutralisation – than anything we’ve seen so far.”

Aside from the theoretical science of why it could be more infectious and dangerous, real world data is also suggesting that omicron could cause serious problems.