The "milder" outcomes of infection from Omicron variant might not be for its properties but likely because more and more people now have immunity against Covid-19, a recent study has pointed out, dispelling some common notions.
The study conducted by researchers from Massachusetts General Hospital and Harvard Medical School in the US was published in the New England Journal of Medicine.
Why Omicron cause mild infections?
As compared with earlier variants, Omicron resulted in lower hospitalisation and death, hence, it was concluded that the variant causes less severe outcomes or is less virulent.
However, the research for this particular study pointed out, by the end of November 2021, when Omicron was first found in Botswana and South Africa, most people in this region had been vaccinated or probably infected by another variant during earlier waves of the pandemic. And, previous exposure would likely have reduced the severity of a subsequent Omicron infection.
The milder symptoms may also be due in part to Omicron's ability to cause breakthrough infections and reinfections, including in people with stronger immune systems who are better equipped to fight off an infection, they said.
Omicron could progress differently in other countries
The situation in South Africa is intrinsically different than that of other countries -- especially the young age of its population -- meaning that Omicron could progress differently in other populations around the world.
Based on their analysis, the researchers stress that as many people as possible globally should be vaccinated, and those most vulnerable to disease should receive a third booster shot.
"There must be a renewed push to vaccinate and boost those not yet protected, because Omicron is not necessarily intrinsically milder," said William Hanage, associate professor at Harvard T.H. Chan School of Public Health.
"This is especially true for those struggling to access vaccines, whether in the United States or elsewhere in the world," Hanage added.
(With inputs from agencies)
