Washington: The Omicron BA.2 subvariant is less severe than the Delta variant and to an even greater extent than the original Omicron variant, according to a research team led by investigators at the US-based Massachusetts General Hospital. Of 1,02,315 confirmed COVID-19 cases in the US from March 3, 2020 to June 20 this year, there were 20,770 labelled as Delta variants, 52,605 labelled as Omicron B.1.1.529 variants, the original Omicron variant, and 28,940 labelled as Omicron BA.2 subvariants, researchers found. Mortality rates were 0.7 per cent for Delta, 0.4 per cent for the original Omicron variant and 0.3 per cent for Omicron BA.2.
The researchers said after adjustments, the odds of death were more than two times higher for the Delta and the original Omicron variant compared with Omicron BA.2.
Patients with Delta and original Omicron variants were also more likely to need hospitalisation, invasive ventilation and intensive care admissions, according to the study, which has been published in the Journal of the American Medical Association (JAMA) Network Open.
These findings suggest that the severity of SARS-Cov-2 may be diminishing, according to the study.
To provide an accurate assessment of the severity of SARS-Cov-2 variants above and beyond previous studies, the researchers used a method called entropy balancing to account for potential confounding factors such as prior infections, vaccinations, treatments and comorbidities.
The team applied this method to data leveraged from the Mass General Brigham’s electronic health record system that is linked to a COVID-19 vaccine registry, the researchers said.
The study’s lead author, Zachary Strasser, said,
While the SARS-CoV-2 virus always has the potential to mutate to a more deadly form, when you look at the recent trajectory of Delta, Omicron BA.1, to Omicron BA.2, the virus seems to be getting intrinsically less severe. Hopefully this trend will continue.
“We can continue to use our analytics system and method to assess many other questions such as which vaccinations have the most impact on preventing long Covid, or whether certain treatments reduce the likelihood of long Covid,” Strasser said.
The Omicron variant of concern was the dominant one earlier in the year, circulating globally and accounting for nearly all sequences reported to GISAID, an initiative which promotes rapid sharing of data from all influenza viruses and the coronavirus causing COVID-19.
Omicron is made up of several sublineages, the most common ones reported at that time being BA.1, BA.1.1 and BA.2.
(This story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ population, indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diarrhoea and the country can become a Swasth or healthy India.