When the B.1.1.7 variant of SARS-CoV-2 was first detected in the UK in December 2020 it was accompanied by unsubstantiated claims of increased transmissibility and virulence. The results of a hospital-based study in London reveals no association of the variant with severe disease in this cohort.
In a note published by NERVTAG on 21 January 2021, the panel concluded that â€˜there is a realistic possibility that infection with VOC B.1.1.7 is associated with an increased risk of death compared to infection with non-VOC viruses.’ The death risk ratio for VOC infected individuals compared with non-VOC infected individuals was 1.65. This conclusion was based on analysis of COVID-19 related deaths at several hospitals in the UK. The authors noted in this report that ‘The data set used in the LSHTM, Imperial, Exeter and PHE analyses is based on a limited subset of the total deaths. This includes approximately 8% of the total deaths occurring during the study periodâ€™.
In the present study, SARS-CoV-2 PCR-positive samples from hospitalized patients were analyzed that had been collected between 9 November and 20 December 2020 in London. Of these, 341 (58%) were infected with B.1.1.7 and 143 (42%) were infected with an ancestral virus. Results of statistical models showed no association between severe disease and death and the B.1.1.7 lineage.
I hope that these results can begin to reverse the disturbing narrative advanced by some that B.1.1.7 is 50% more virulent than its ancestor. This conclusion was never firmly grounded, yet it has been echoed by mainstream media as if it were dogma.
Unfortunately the authors of this paper continue to promote the idea that B.1.1.7 viruses are more transmissible. Their conclusion is based on increased levels of viral RNA in patient samples as determined by RT-PCR (cycle threshold 28.8 in VOC infected patients versus 32.0 in non-VOC infected patients) and genomic reads by sequencing (1280 vs 831). Increased viral load determined by these methods might be an indication of increased viral fitness, but it does not prove increased transmission. It is not known if VOC-infected patients shed more infectious virus, which might be consistent with increased transmission. Until such experiments are done, it can only be speculated that B.1.1.7 and other VOC have increased transmissibility.