I read this hocus pocus this morning in the Spectator:

Moderna says its vaccine ‘retains neutralising activity’ against Covid-19 strains identified in the UK and South Africa, but there is a ‘sixfold reduction’ in neutralising activity against the latter. The company is also developing a booster shot against that strain.

I believe it's about 60% effective in its current form, so to have less than a 10% "neutralising activity" hardly seems worth the risk of the unproven jab, does it?