The speed at which the Omicron variant appears to have accumulated its unusual pattern of mutations is a cause for concern, according to Sikhulile Moyo, the researcher who first detected the new strain that has spread rapidly around the world.
The speed of the mutations also raises questions about how the variant evolved and adds to the conundrum about how transmissible the variant might be.
Moyo, director of the Botswana Harvard HIV Reference Laboratory and a researcher at the Harvard T.H. Chan School of Public Health, told a briefing that the virus doesn’t accumulate mutations in a single stage, according to Bloomberg. Given the global lack of proper sequencing of the coronavirus, it’s very hard to tell how quickly the Omicron variant has developed.
“We’re still trying to understand how so many mutations emerged in such a short period of time,” he said. “If you look at the previous lines, if you look at alpha, if you look at beta, you can see that the mutations have accumulated over time.”
One theory is that this strain developed in a person with compromised immunity who had been harboring the virus for much longer than normal. However, Moyo cautioned that there is no evidence for this. Another hypothesis being explored is whether it could have transferred from humans to an animal host, adapted relatively quickly to that host and then moved back to humans.
When Moyo first sequenced the sample, taken on 11 November from foreign diplomats travelling together in Botswana, the variant it most closely resembled was B.1.1.263. This variant is known as the U.A.E. line and was first detected in early April 2020.
Omicron can reproduce quickly
When he looked more closely at B.1.1.263, he saw that strain had fewer mutations and ruled out that what he was seeing was the same thing. After requesting more information from Botswana’s health department about who the positive samples had come from, Moyo and his team added their findings to an international database on 23 November. A few hours later, another group in South Africa reported similar findings, followed by another group in Hong Kong.
Given Omicron’s large number of changes, Moyo initially thought it would be a weak virus. Instead, it appeared to be able to reproduce rapidly and evade parts of the immune system, causing a higher risk of reinfection.
In South Africa, daily confirmed cases of Covid-19 have nearly quadrupled since last Tuesday as the variant spread across the country, showing just how contagious the new strain can be.
