More Excess Deaths During Omicron Period Than During Delta: US Localised Study

More excess deaths due to Covid-19 occurred during the Omicron period than during the Delta period in Massachusetts, United States, according to a new localised study.

New Delhi: More excess deaths due to Covid-19 occurred during the Omicron period than during the Delta period in Massachusetts, United States, according to a new localised study. Excess deaths are a higher number of fatalities than would be expected over a given period. 

The new study, conducted by physicians at Brigham and Women's Hospital, Massachusetts, was recently published in the Journal of the American Medical Association, a peer-reviewed medical journal. 

When Did Excess Deaths Occur?

Excess deaths occurred during the pandemic period when the Delta variant dominated, during the transition from Delta to the Omicron variant, and when Omicron dominated in Massachusetts. The Delta variant dominated from June 28, 2021 to December 5, 2021; the transition from Delta to Omicron occurred from December 6 to 26, 2021; and Omicron dominated from December 27, 2021, to February 20, 2022 in Massachusetts. 

According to the study, the excess deaths were higher during the 8-week Omicron period compared to the 23-week Delta period. In the Omicron period, the number of deaths was 2,294. Meanwhile, the number of deaths in the Delta period was 1,975. 

Study Addresses An Important Question

Jeremy Faust, MD, Department of Emergency Medicine, Brigham and Women's Hospital, corresponding author on the paper, said in terms of excess health, the physicians found that Omicron was actually much worse for Massachusetts than Delta, according to a statement released by the hospital. 

While the study was localised to Massachusetts, it addresses an important question: which of the two waves was deadlier. Faust added that 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," Faust was quoted as saying in the release. 

A new study has shown the BA.2 subvariant of Omicron is similar to BA.1 in both severity of illness and the ability to cause infection. Omicron is the dominant version of SARS-CoV-2 and BA.2 is the dominant subvariant causing Covid-19 in nearly seven dozen countries. 

According to the study, existing therapeutic monoclonal antibodies and antiviral drugs were found to remain effective against BA.2. Monoclonal antibodies are man-made proteins that act like human antibodies in the immune system. 

Plasma from vaccinated individuals and from people who recovered from earlier infections was less effective at neutralising both subvariants of Omicron relative to earlier virus strains. Also, plasma from people infected with BA.1 was less effective at neutralising BA.2.

Then, the study found that plasma from people who were vaccinated and then infected with BA.1 or earlier variants exhibited a smaller decrease in effectiveness against BA.2.