The warning from the head of Moderna, the pharmaceuticals group, that Covid-19 vaccines were likely to be less effective against the Omicron variant has provoked anxiety over the best weapon the world has to fight the pandemic.
While the boss of vaccine developer BioNTech offered reassurance that the fully inoculated would have a “high level of protection against severe disease” from the new strain, there is as yet no conclusive evidence on how immune protection holds up against the heavily mutated variant.
Scientists who had not even heard of Omicron a week ago are racing to stress-test the existing jabs, while preparing a new vaccine formula tailored to the emerging threat.
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