It has been the perception so far that the Omicron variant of COVID-19 is generally mild. However, a new study has found that it is as deadly as previous variants like Delta and Alpha. It is pertinent to mention that these strains have claimed thousands of lives globally.
For the uninitiated, Omicron was first detected in South Africa in November last year. It has widely been reported that despite being more transmissible, the strain is less severe than other variants of COVID-19. Several studies conducted in the United Kingdom, South Africa, Canada and others have so far only said that Omicron is more transmissible.
It was also reported that Omicron has caused less hospitalisation and death in comparison to other variants. It was found to be affecting the upper airways more than the lungs. But the World Health Organization has time and again warned that it should not be taken lightly.
But, the study led by the Massachusetts General Hospital and Harvard Medical School found that the risks of hospitalisation and mortality were “nearly identical between previous waves of Covid-19”.
“Our analysis suggests that the intrinsic severity of the Omicron variant may be as severe as previous variants,” the researchers claimed in the pre-print study, meaning not yet peer-reviewed.
The new study also provided evidence that COVID-19 vaccines helped save lives.
In the study, the team linked state-level vaccination data with quality-controlled electronic health records from a large healthcare system, including 13 hospitals, in Massachusetts.
They then performed a weighted case-control study to compare risks of hospital admission and mortality across the SARS-CoV-2 waves in over 130,000 Covid patients.
The unadjusted rates of hospital admission and mortality appeared to be higher in previous waves compared to the Omicron period.
But, our findings suggest that after accounting for confounders, including various demographics, and vaccination status, “the Omicron variant was as deadly as the previous SARS-CoV-2 waves”, wrote the researchers, including Zachary H. Strasse from MGH, in the study.
The team also acknowledged limitations in their report, including the possibility that the analysis underestimated the number of vaccinated patients in more recent Covid waves, and the total number of infections, because it excluded patients who performed at-home rapid tests.