Cambridge researchers are continuing to regularly take blood from more than 150 volunteers, to check those most at risk from Covid-19 are still being protected by vaccines.

The researchers have been using the volunteers' blood to check how well vaccines deal with new variants.

After blood has been given by a volunteer, it is carried about 400m (1,312ft) across the city's Biomedical Campus to a state-of-the art lab run by Prof Gupta.

Prof Gupta said: "Our focus really has been the elderly and individuals who are taking various drugs or who have had cancers who don't respond so well to vaccines, and really understanding how well their immune systems will respond to vaccines, especially as new variants come along.

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