Because an immunocompromised host doesn’t produce numerous antibodies, many viruses are left to propagate. And new mutant viruses that resist the antibodies can multiply.
A mutation that permits a virus to evade antibodies isn’t essentially advantageous. It may make the virus’s spike protein unstable in order that it might probably’t latch shortly onto a cell, for instance. But inside somebody with a weak immune system, viruses might be able to achieve a brand new mutation that stabilizes the spike once more.
Similar mutations may have constructed upon themselves repeatedly in the identical individual, Dr. Pond speculates, till Omicron developed a spike protein with simply the best mixture of mutations to permit it to unfold supremely nicely amongst wholesome individuals.
“It certainly seems plausible,” stated Sarah Otto, an evolutionary biologist on the University of British Columbia who was not concerned within the research. But she stated scientists nonetheless wanted to run experiments to rule out different explanations.
It’s attainable, for instance, that the 13 spike mutations supply no profit to Omicron in any respect. Instead, a few of the different spike mutations could possibly be making Omicron profitable, and the 13 are simply alongside for the journey.
“I would be cautious about interpreting the data to indicate that all of these previously deleterious mutations have been adaptively favored,” Dr. Otto stated.
Dr. Pond additionally acknowledged that his speculation nonetheless has some large gaps. For instance, it’s not clear why, throughout a power an infection, Omicron would have gained a bonus from its new “bubble” methodology for stepping into cells.
“We just lack imagination,” Dr. Pond stated.
James Lloyd-Smith, a illness ecologist at U.C.L.A. who was not concerned within the research, stated that the analysis revealed simply how exhausting it’s to reconstruct the evolution of a virus, even one which arose not too long ago. “Nature is certainly doing its part to keep us humble,” he stated.