Higher excess mortality found in Massachusetts during Omicron period than the Delta period

Reviewed by Emily Henderson, B.Sc.May 22 2022

The COVID-19 pandemic has led to excess deaths -; a higher number of fatalities than would be expected over a given period. A new study compares excess deaths during the pandemic period when the Delta variant dominated (June 28, 2021-December 5, 2021), during the transition from Delta to the Omicron variant (December 6-26, 2021) and when Omicron dominated (December 27, 2021-February 20, 2022) in Massachusetts. Investigators found that excess deaths were higher during the 8-week Omicron period compared to the 23-week Delta period (2,294 deaths versus 1,975).

In terms of excess death, we found that Omicron was actually much worse for Massachusetts than Delta. Others have reported that the Omicron variant may cause milder COVID-19. Assuming that's the case, 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 vaccinated population."

Jeremy Faust, MD, Department of Emergency Medicine, Brigham and Women's Hospital