News Scan for May 20, 2022

Study: Omicron caused 3 times as many deaths as Delta in MassachusettsMore adults died of COVID-19 in Massachusetts in the first 8 weeks of the SARS-CoV-2 Omicron variant surge than in the entire 23-week Delta period, suggests a modeling study published today in JAMA.A team led by a Brigham and Women's Hospital researchers estimated excess deaths—a higher-than-expected number of fatalities—during Delta dominance (Jun 28 to Dec 5, 2021), the transition to Omicron (Dec 6 to 26, 2021), and Omicron dominance (Dec 27, 2021, to Feb 20, 2022) in Massachusetts.The team applied models to 2014 to 2019 US Census population data and Massachusetts Department of Health all-cause death data from Jan 5, 2015, to Feb 8, 2020.

They determined the variant periods using regional wastewater sampling data.More excess deaths occurred in the 8-week Omicron period (2,294; 12,231 observed, 9,937 expected) than in the 23-week Delta surge (1,975; 27,265 observed, 25,290 expected), suggesting that Omicron—despite it generally causing milder infections—was deadlier overall.

The per-week incidence rate ratio of Omicron to Delta for excess death was 3.34.All adult age-groups saw statistically significant excess deaths during both periods, although more deaths occurred in older adults."In terms of excess death, we found that Omicron was actually much worse for Massachusetts than Delta,” lead author Jeremy Faust, MD, said in a Brigham and Women's news release.If Omicron causes less severe COVID-19, he said, "What we’re seeing here may reflect just how much more infectious Omicron has been.

This could mean that highly contagious variants, even if they cause relatively milder illness, can still lead to substantial excess mortality, even in a highly