We have known for some weeks now that the transmissibility of COVID-19 is higher than the version that took hold in Europe and in the United States (which itself displaced the original variant of COVID-19 that came out of Wuhan). Early indications were that the transmissibility of the B.1.1.7 variant was over 30% more infectious than “classic” COVID.
The fact that B.1.1.7 is more transmissible has led to calls for improved masking, speeding up of vaccine roll-outs, along with dire warnings that cases with the B.1.1.7 variant are doubling every eight to ten days in the States.
Now, out of the UK health agency SAGE (Scientific Advisory Group for Emergencies) comes new data (PDF) that further underscores the need for diligence in personal protection, and for moving to get shots into arms as expeditiously as possible. For, not only is B.1.1.7 significantly more transmissible, it is now declared to be anywhere up to 70% more deadly.
Independent analyses of the risk of hospitalisation and death for S-gene target failure (SGTF; a proxy for VOC (Variant of Concern) B.1.1.7 in the UK) cases and non-SGTF (non-VOC) cases are (also see data table in annex):
LSHTM (London School of Hygiene & Tropical Medicine): reported that the relative hazard of death within 28 days of test for VOC-infected individuals compared to non-VOC was 1.58 (95%CI 1.40–1.79), or 1.71 (95% CI 1.48- 1.97) if adjustment is made for misclassification of SGTF and missingness of data.
Imperial College London: mean ratio of case fatality ratio (CFR) for VOC- infected individuals compared to non-VOC was 1.36 (95%CI 1.18-1.56) by a case-control weighting method, 1.29 (95%CI 1.07-1.54) by a standardised CFR method.
University of Exeter: an updated analysis estimated the mortality hazard ratio for VOC-infected individuals compared to non-VOC was 1.7 (95% CI 1.3 – 2.2) in a matched cohort study.
Public Health England: an updated matched cohort analysis has reported a death risk ratio for VOC-infected individuals compared to non-VOC of 1.65 (95%CI 1.21-2.25).
Public Health Scotland: the REACT-SCOT study found that the hazard ratio was 1.08 (95% CI 0.78-1.49) for death and 1.40 (95% CI 1.28-1.53) for death or hospital admission in SGTF compared to non-SGTF cases.
There are some case-fatality ratio reports that fall below these levels, more of which you can see in the linked PDF file.
This is, to put matters bluntly, a very worrying development. Thankfully the current range of vaccines are effective against the B.1.1.7 variant — if and when you can get a shot!