PHE have published a rapid epidemiological comparison of the SARS-CoV-2 variant (VOC 202012/01 aka B1.1.7) with ‘wild-type’ SARS-Cov-2 in this country. Most of the characteristics don’t look to be different – the variant is not associated with more hospitalizations or an increase in 28-day mortality. However, there does seem to be an increase in secondary attack rates of the variant compared with wild-type SARS-CoV-2.
The matched cohort study included 1,769 variant cases matched on specimen date, age, location, and gender with an equal number wild-type comparator cases.
There were no significant differences in hospitalizations, 28-day mortality, or the rate of apparent re-infections (which was very low in both groups, with only five identified in total). However, variant cases were more likely to be:
- Identified in a residential cluster (63.5% vs 56.1%, Chi-Squared test p<0.01).
- The secondary attack rate amongst contacts identified by NHS Test and Trace was 15.1% for variant cases and 9.8% for wild-type cases.
These findings seem to reinforce that this variant is no more virulent but does seem to be more transmissible than wild-type SARS-CoV-2.