By Nic Lewis
Key points
- A new variant, B.1.1.7, of the SARS-CoV-2 virus has recently spread rapidly in England
- The public health agency’s best estimate of B.1.1.7’s weekly growth rate advantage is 1.51x
- They mis-convert this in a reproduction number ratio of 1.47; converting appropriately gives a ratio of 1.25
- Confident claims by the UK government scientific advisers that the higher growth of B.1.1.7 is due to increased transmissibility are misplaced; it could be partly of wholly due to other factors
- 1.1.7 has not shown a greater growth rate advantage than two previous variants did, both of which are now thought to have no greater transmissibility than previously existing variants
- There is little evidence that B.1.1.7 is more virulent, or likely to be resistant to existing vaccines
