June saw the return of Covid in a big way for London and the UK.
While in much of Europe/USA, a covid case is now a rarity, in the UK case numbers are up dramatically – 20-fold in my part of London for instance (see graph below). The Delta variant now accounts for >90% of the cases and, wow, does it spread easily. Other countries, notably Australia, will almost certainly have some of this to come – but you hear it from London first.

The UK is aiming to outrun the Delta variant by vaccinating. The complication with this plan is that you need two jabs to have even a hope of avoiding Delta, and if you have AstraZeneca than your hope is only a 60% hope even with 2 jabs. A virus with an underlying reproductive factor of 8 laughs at protection of only 60% – reducing 8 by 60% leaves the Delta variant with the same reproductive ratio as the original Covid-19 variant.
Continue reading “June 2021 – Alpha, Beta and Delta”