Here in New York, the Omicron Variant Is Getting Weird | by Donald G. McNeil Jr. | Dec, 2021 | Medium

Weird Thing Four: In the last three days, an unusual mutation has cropped up more than 60 times in genetic sequences of the Omicron variant released by the NYU Langone genetics lab.

The mutation, known as P681R, inserts an R (for the amino acid arginine) at position 681 in the spike protein gene instead of a P (for proline). According to Henry L. Niman, an independent tracker of viral mutations, that change could enhance the virus s cleavage site so it is better able to attack different kinds of human cells. (After attaching to a cell, the virus s shell needs to cleave or split, so it can inject its RNA payload.) Being able to cleave to lung cells or heart cells instead of just to nose cells would make a virus more dangerous.)

A similar change in avian flu genes makes mild flus into bird killers, Dr. Niman said.

Whether or not this is worrisome remains to be seen.

Dr. Niman has tracked such mutations, especially in flu samples, for many years long before science journalists routinely paid attention to them. That has made him a thorn in the side of the C.D.C., which is cautious about reacting to such changes. Sometimes his warnings prove alarmist; sometimes he s been dead right.

In 2006, he was right that there were more cases of human-to-human transmission of H5N1 bird flu than had been acknowledged. In 2009, he was right in predicting that the H1N1 swine flu in Mexico would reach the United States and that Tamiflu resistance in it would spread. In 2015, he was overly worried about a circulating H5N2 bird flu. Earlier in this pandemic, he was correct to worry about the D614G mutation in the Wuhan variant and E484K mutation in the British one.

This combines Omicron s rapid spread with Delta s lethality, he said.

Dr. tenOever s reaction was that the mutation bore watching but it was not a foregone conclusion that it would confer more pathogenicity. If such sequences turned up mostly in I.C.U. patients that would be worrying, he said.

It s early days still but, as it did last spring, New Y

via donaldgmcneiljr1954.medium.com

Someone should ask Dr. Fauci if he still thinks it was a good idea to stick the cleavage site in there.