skip to Cookie NoticeSkip to contents

Your health and safety remain our top priority: Learn about our Safe Care Commitment | Use our Prescreen app before arrival for faster entry | Read the COVID-19 Vaccine FAQs

Header Skipped.

Research Briefs

May 20, 2022

Study Finds Higher Excess Deaths During Omicron Period Compared to Delta Period in Massachusetts

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 in JAMA 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,” said Jeremy Faust, MD, Department of Emergency Medicine, Brigham and Women’s Hospital, corresponding author of JAMA paper. “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.”