Note: No Q&A tomorrow.  Back at it on Monday!

Question: I was just reading that the B.1.1.7 variant (UK variant) has “grown to account for more than 20 percent of new U.S. cases as of this week.”  I know it’s far more transmissible, but is it also more deadly?

Answer: As the New York Times reported earlier today, the share of US cases attributable to the B.1.1.7 variant has grown exponentially (Figure 1).  Unfortunately, evidence is accumulating that the variant is not only more transmissible, but is also associated with increased disease severity, including death.  We last discussed the disease severity issue in our Q&A of 1/5 and since then, we know a lot more.  I’ve included a description of a recent study and a research synthesis herein.  As always, please keep masking, distancing, washing hands, and avoiding the 3Cs of closed spaces, crowded places, and close-contact settings. These behaviors work to keep us all safe.  And when it’s your turn, please get vaccinated.

• This preprint (not yet peer reviewed) study posted four days ago, Increased Risk of Hospitalisation Associated with Infection with SARS-CoV-2 Lineage B.1.1.7 in Denmark, examined hospitalization rates among individuals in Denmark who tested positive for COVID between 1st January and 9th February 2021.  Because Denmark’s genomic sequencing is widespread, researchers were able to split their observational cohort into two groups: a) those with the variant; and b) those without the variant.  Controlling for age, sex, region, comorbidities, and several other factors, researchers found that those who were infected with the B.1.1.7 variant had 1.64x higher odds of hospital admission (95% confidence interval 1.32-2.04).  
• The New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG), a government advisory group to the UK presented a synthesis of evidence on 1/21, which it updated with new evidence (~1 dozen studies) on 2/11.  For example, one study included in the update was from the London School of Hygiene and Tropical Health, which found the risk of death (relative hazard of death) within 28 days of a positive test to be 1.58x higher for individuals infected with the variant (95%CI 1.40–1.79).  Based on its review of current evidence NERVTAG concluded, “it is likely that infection with VOC B.1.1.7 is associated with an increased risk of hospitalisation and death compared to infection with non-VOC viruses.”  

Figure 1. Growth of B.1.1.7 Variant Cases in the US (from NY Times)