“That’s to be expected, we know that these vaccines aren’t 100 per cent protecting you against infection and that’s why we ask people to take caution,” she said.
“You can see that they’re not as good against the South African variant as they are against our own B117 at preventing infection and transmission.”
Dr Hopkins added that vaccination does offer some protection against variants because they act as a “primer for your immune system”.
“When your immune system is exposed to a variation of the same virus it responds faster and more adequately to protect you against severe disease,” she said.
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A “significant” cluster of the South African variant identified in south London meant that additional Covid-19 testing facilities were recently set up in Lambeth, Wandsworth and Southwark.
The Kent variant, or B117, which emerged in the UK last year has, meanwhile, been found to be more transmissible than the virus in its original form.
Scientists are also concerned by a new variant that was first identified in India. More than 70 cases of the B.1.617 variant have been confirmed in the UK.
Dr Hopkins said that there is not yet enough data to classify the strain as a “variant of concern” but investigations are ongoing.
“To escalate it up the ranking we need to know that it is increased transmissibility, increased severity or vaccine evading, and we just don’t have that yet,” she said.
There are currently seven variants under investigation in the UK.
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