Scientists are developing a range of second-generation Covid vaccines aimed at expanding protection against the disease.
Candidates include one version that could provide immune defence against many different virus variants, while other researchers are investigating vaccines that would generate responses aimed specifically at blocking transmission of the disease.
Other projects include research into the creation of multiple vaccines that could each tackle different virus strains but would be administered as a single jab in a manner similar to annual flu jabs, which currently combine four vaccines against different strains of the influenza virus.
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At present, Covid vaccines are designed to stop infected people becoming seriously ill, to prevent hospitalisations and deaths. It is not known yet how effective they are at blocking viruses passing from person to another.
“There is no indication that any of the new virus variants that have appeared recently are causing more severe disease than the original virus,” said Professor Jonathan Ball, a virologist at Nottingham University. “However, there is evidence that