SHOT IN THE DARK

Fears Covid vaccine will be LESS effective against new Brazilian mutant strain

A NEW strain of the coronavirus from Brazil has the potential to evade vaccines.

It's the third new variant to emerge in the past two months, adding to one identified in the UK, and another in South Africa.

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Vaccines may be less effective against new variants. Pictured: A patient receives a jab in Stevenage, January 14Credit: Getty Images - Getty

Britain now has three vaccines approved against the coronavirus, from drug giants Pfizer, AstraZeneca (Oxford's) and Moderna.

There are fears the new mutations will be able to dodge the immune system, even after vaccination or previous infection.

Professor Sharon Peacock, who is leading research into new variants in the UK, said some mutations are of "sufficient" concern to need in-depth research in the laboratory.

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And the UK’s Chief Scientific Adviser Sir Patrick Vallance admitted “we don’t know for sure” if the vaccines being rolled out on the NHS will work on the strains from Brazil and South Africa.

He told ITV's Peston: “There’s a bit more of a risk that this might make a change to the way the immune system recognizes it but we don’t know.

"Those experiments are underway,” Sir Patrick said.

It comes as:

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The vaccines being used in the UK work by instructing the body's own cells to produce spike proteins found on the surface of the virus.

The immune system spots these proteins and develops killer antibodies.

When the real virus comes along, the immune system has a memory of the "spike" on the surface, and is primed to attack it.

However a change in the shape of the spike protein makes it more difficult for the immune system to recognise the virus.

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Sir Patrick Vallance, pictured at a December No10 briefing, admitted “we don’t know for sure” if the vaccines will work against the Brazilian and South African strainsCredit: PA:Press Association
How the Oxford/AstraZeneca vaccine works
How Pfizer's vaccine works

Simon Clarke, an associate professor in cellular microbiology, told The Sun: "With all three of the troublesome new variants there are changes to the shape of the spike protein on the surface of the virus, which is the target for the vaccines.

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"The spike protein acts a bit like the virus’ key to unlock and enter our cells; some of the changes are in the bit of the spike that does the unlocking.

"There is concern that some of the changes found in these variants may interfere with the ability of antibodies to stick to the 'key' and block it from working."

Prof Ravi Gupta, professor of microbiology at the University of Cambridge, said the variant from Brazil - called B.1.1.248 - has three key mutations in part of the virus called the spike receptor binding domain (RBD).

The mutations "largely mirror some of the mutations we are worried about it in the South African variant, hence the concern", he said.

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"The SARS-CoV-2 RBD is one of the main targets for our immune defences and also the region targeted by vaccines and changes within this region are therefore worrisome," he said.

But he reassured that "vaccines are still likely to be effective as a control measure if coverage rates are high and transmission is limited as far as possible".

It comes after Prime Minister Boris Johnson told MPs yesterday: "There are lots of questions we still have about that variant, we don't know for instance, any more than we know whether the South African variant is vaccine resistant."

He admitted: "We are concerned about the new Brazilian variant."

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