An update on Variants of Concern and UK vaccine effectiveness data

This information is sourced from The PHE Greenbook, a Gov UK press release, a medRxiv preprint study, The Guardian the WHO and Nature:

PLEASE NOTE: THIS IS NO LONGER RELEVANT AND IS NOT BEING UPDATED BUT HAS BEEN LEFT ON THE SITE FOR REFERENCE PURPOSES ONLY

Variants of Concern

The WHO have introduced a naming scheme for Variants of Concern which aims to avoid confusion and stigmatisation:

UK Vaccine effectiveness

Up to three-quarters of new UK Covid cases are now thought to be caused by the variant first detected in India (Delta)

Updates on the real world effectiveness of Covid vaccines are now published by PHE on a weekly basis

In those who had had 2 doses of a vaccine

• The Pfizer vaccine is 88% effective against symptomatic disease from the Delta variant 2 weeks after the second dose, compared to 93% effectiveness against the Alpha variant
• 2 doses of the AstraZeneca vaccine is 60% effective against symptomatic disease from the Delta variant compared to 66% effectiveness against the Alpha variant

In those who had had 1 dose of a vaccine

• Both vaccines are 33% effective against symptomatic disease from Delta , 3 weeks after the first dose compared to around 50% effectiveness against the Alpha variant

Protection against hospitalisation

• Two doses of Covid vaccine provide over 90% protection against hospitalisation with severe Covid. This level of protection been maintained since the delta variant was introduced to the UK

Written by Dr Poppy Freeman