The Omicron variant of coronavirus was first detected in South Africa last November and since then this variant has spread rapidly across the world. Omicron’s rapid transmissibility has sparked record waves of infection in the U.S., Europe, and Asia. But despite of its high transmissibility, Omicron has appeared less fatal than its prior variants, with hospitalization rates among vaccinated people remaining relatively low.
Meanwhile, the WHO has warned the world that it might not get so lucky with the next variant.
The World Health Organization’s technical lead on COVID-19, said in a press briefing on Tuesday Maria Van Kerkhove, “The next variant of concern will be more fit, and what we mean by that is it will be more transmissible because it will have to overtake what is currently circulating.” “The big question is whether or not future variants will be more or less severe.”
The WHO defines a “variant of concern” as any variant that either weakens the effectiveness of vaccines or increases transmissibility or virulence to a degree “of global public health significance.” Between Delta and Omicron, the WHO considered variants like Lambda and Mu as “variants of interest.” But Lambda and Mu did not spread quickly or broadly enough to warrant “variant of concern” status.
After Delta, Omicron is the only variant that WHO has put under the variant of concern. Omicron’s improved ability to escape vaccines as well as its heightened spread makes now dominant variant between two and four times more transmissible than Delta.
Naturally, the WHO’s next “variant of concern” will be in some way more infectious than Omicron currently. But some experts believe that future COVID-19 strains will become increasingly weak, even as the virus becomes more communicable.
“There is a natural selection that the virus will become less virulent to become more transmissible… A virus is a parasite. It requires a host to survive. The worst thing for the virus is to kill off its host,” Shiu-Wan Chan, lecturer and principal investigator in molecular virology at the University of Manchester told Fortune last week. However, not everyone agrees.
Zeynep Tufekci, a sociologist and pandemic expert, told the New York Times it is “purely luck” if a virus becomes weaker as it evolves, and that viruses “don’t care if you eventually die as long as they transmit through you.”
Van Kerkhove appears to side with Tufekci’s view. The WHO official cautioned on Tuesday that there is “no guarantee” the coronavirus will get weedier as it grows and that although the world might hope that’s the case, “we can’t bank on it.”
Health authorities might find out whether Omicron’s successor is more or less deadly than the current variant sooner than they hoped. This week the WHO announced that a new Omicron subvariant called BA.2, which is often dubbed “stealth Omicron,” should be investigated and studied separately from the globally dominant Omicron subvariant, BA.1.
“The BA.2 descendent lineage, which differs from BA.1 in some of the mutations, including in the spike protein, is increasing in many countries,” the WHO said. “Investigations into the characteristics of BA.2, including immune escape properties and virulence, should be prioritized independently (and comparatively) to BA.1.”
