The virus that causes COVID-19 has evolved rapidly, blindsiding the world with one variant after another.
The World Health Organization hasn't given a Greek name to a new variant of the disease in almost a year, a move that is reserved for new versions that could have a significant public health impact.
The question is if the evolution of the virus has finally started to ebb.
According to a dozen evolutionary biologists, the answer is not yes.
The evolution of the viruses at the Fred Hutchinson Cancer Center in Seattle is being studied by a Computational Biologist. The evolution is not slowing down.
The most consequential evolutionary changes have remained within the omicron family.
The branches that sprouted on the family tree weredwarfed by the omicron bough, which is studded with a plethora of sub-variant stems.
The children of omicron have displaced each other as the dominant strains driving the epidemic. The same family has dominated.
According to Manon Ragonnet-Cronin, who studies viral genetics at the University of Chicago, the omicron brood has maintained its dominance throughconvergent evolution.
Ragonnet-Cronin says that they are seeing for the first time evidence of widescale convergent evolution. There is a swarm of omicron viruses, which have different ancestries within omicron, but which have the same set of genes.
The ability to sneak past the immunity that people have built up from getting infections is the most important power these omicron offspring have.
"If you see convergence in evolution that's evolution's way of saying 'this mutation is repeatedly getting selected over and over again because it's really helpful'," says Jesse Bloom, a Computational Biologist at the Fred Hutchinson Cancer Center in Seattle.
The increase in the number of people who have been affected by the virus has been due to the increase in the ability of it to evade protective antibodies.
If you will, you will see a lot of lottery tickets. Jeremy Kamil is an immunologist at Louisiana State University.
There are more than a dozen omicron subvariants that are being tracked by the Centers for Disease Control and Prevention.
The immunity people have built up from vaccinations appears to be protecting them from serious illnesses and deaths.
The newer omicron subvariants are highly contagious. They give the virus a lot of chances to grow.
The long period of dominance of omicron is giving some scientists hope.
The virus could evolve this way for a long time, drifting in more subtle evolutionary directions, without sudden shifts in how it behaves that make it more dangerous.
The fact that we've stepped out of a phase where we're getting completely new viruses from different parts of the tree sweeping in and dominating may be a sign that we're moving towards a more stable future for the virus.
Large numbers of people would still be affected by the virus. It's not possible to know how the virus will evolve in the future because it is so new.
"We are dealing with a completely novel virus here, that's what we're dealing with," says Andersen. We don't know how many other paths the virus may have. At this point, we don't know.
There is no way to rule out the possibility of a dramatically different variant emerging again, perhaps after someone with a compromised immune system is exposed to the virus. The human immune system allows the virus to interact with it.
"I guarantee you that there are people who have been persistentlyinfecting with delta and alpha who have some really weird combinations ofmutations," says Michael, an evolutionary biologist at the University of Arizona. I'm fully prepared for a zombie virus that's been cooking away within someone to emerge.
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