The B.1.1.7 variant of SARS-CoV-2 is not associated with more severe illness or death but leads to higher viral load and is associated with increased effective reproduction number, R1, according to two studies published in The Lancet Infectious Diseases and The Lancet Public Health. Investigators who sequenced and analyzed samples from hospitalized patients for the presence of the B.1.1.7 variant of concern found that 58% of the 341 patients with samples that could be sequenced had B.1.1.7 infection. In unadjusted and adjusted analyses, there was no evidence of a correlation between severe disease and death and lineage. Viral load by proxy was higher in B.1.1.7 samples than in non-B.1.1.7 samples. For the other study, a team examined the association between the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility among users of the COVID Symptom Study app with a positive COVID-19 test between September 28 and December 27, 2020, when the prevalence of B.1.1.7 increased. The researchers observed no change in reported symptoms or disease duration associated with B.1.1.7. Possible reinfections were identified during this time for 0.7% of 36,509 app users who reported a positive test before October 1, 2020, with no evidence for increased frequency of reinfection with the B.1.1.7 variant. Relative to preexisting variants, there was a multiplicative increase in the R1 of B.1.1.7 by a factor of 1.35.
