The researchers at Boston University have claimed that they have developed a Covid-19 strain that inflicts severe disease and has 80 per cent kill rate.
The ones that are dominant across the world such as the sub-variants of Omicron are said to be mild when it comes to their severity.
To develop the most lethal Covid strain, the researchers, according to a report, extracted the spike protein from Omicron and genetically engineered it into the strain of Covid-19 which was first detected in China’s Wuhan and tried it on mice.
The researchers said in their research paper: "In…mice, while Omicron causes mild, non-fatal infection, the Omicron S-carrying virus inflicts severe disease with a mortality rate of 80 per cent." While 80 per cent of mice died from the new man-made Covid strain, none faced a similar fate from a milder Omicron variant, the researchers found.