Ring in the New Year

XBB.1.5 rises to the top of the variant pile

I would ask you not to get bogged down or bored by the viral gumbo of this first section today, it’s some necessary background that is important to the information that follows. We have been monitoring the variant XBB.1.5 since it was first flagged as having a particular spike mutation felt to be very concerning for increased transmissibility. The parental variant XBB is a recombination of two other members in the BA.2 lineage. The variant now causing concern appeared in New York several weeks ago and harbors 3 new mutations. One of these (position 486) is located at a critical site in the Receptor Binding Domain (RBD), and is the bad boy. It has been speculated that this new variant is fueling the explosive growth of COVID cases in New York and the northeast, and that is fairly certain now with the Friday update of the CDC NowCast data. For the first time the CDC is now showing XBB.1.5 separated out from the other XBB variants, and it’s growth is huge. You will see in the following graphic how XBB.1.5 (purple) is rapidly outpacing all other circulating variants. The previously dominant BQ variants are quickly being replaced. (If your interest ranges into the geeky category, check back to last weeks chart)

What is concerning is that we are seeing a significant rise in hospitalizations in New York and the northeast, not just case numbers. Of course those hospital admissions are heavily weighted to the older age group, especially the over 70 crowd. This CDC graph of the country as a whole shows this by age group, and the table next to it indicates that hospitalizations in the 70+ group at 8.6/ 100,000 are now at the highest level since February 17th, 2022. The Connecticut State Department of Health is reporting an 89% increase in COVID hospital admissions since the week of Thanksgiving.

Since last week’s post, unpublished data (Tweet of Dec 27th) from virologist Yunlong Cao shows that XBB.1.5 has approximately the same level of immune evasion as XBB (which is the highest noted of any variant). The mutation in the RBD however gives this new variant a substantial increase in its ability to adhere to the human ACE2 receptor. It has been awhile since we saw a SARS2-COV19 variant rise to dominance based on its increased adherence to the ACE2 molecule. That was the preferred mechanism of increasing viral fitness early in the game, when there wasn’t much, if any population immunity. The Sons of Omicron era has been dominated by successive quantum leaps in immune evasion. Looking back just a short time, we had a variant BA.2.75, which was concerning because of its extremely high affinity for the receptor—but it fizzled out and went nowhere because it lacked a sufficient degree of immune evasion. Enter XBB.1.5 which is factory equipped with the most advanced immune evasion available on the viral market, coupled with ultra enhanced receptor binding. It is guaranteed this new model will be on display in the next few weeks, no matter where you live.

Last week I included a graph of the wastewater COVID RNA levels in my Colorado home town. Below is the CDC graphic of nation wide COVID wastewater surveillance. It is that oddly difficult to understand graph where the areas of red and orange reflect how many communities are seeing an increase and dark blue how many are in decrease. Take a look at the black line, that is the total number of systems doing active monitoring. It shows a precipitous drop; people are tired of hearing about COVID, their are tired of adjusting their behavior, there’s less money around (the government is busy printing it for other uses now). It is a bit ironic, but not surprising that the significant drop off in monitoring was timed to coincide with what we all knew would be the annual big winter wave of illness.

That brings me to the final point today. Just another shout out to China. After criticism from any number of nations, and having the WHO chastise them for failing to tell the Truth about the disaster unfolding there, the Chinese Minister of Health got on the bully pulpit to reassure the world that China was giving everyone the most accurate up to date information, and sharing all knowledge as quickly as possible. China reported 1 COVID death Monday and 3 on Wednesday. There are none of the specific antiviral therapies that save lives available anywhere in China (except perhaps for Xi and some top Mafia (sorry Party) Members. Internal Chinese Health Ministry documents have been leaked showing millions of infections a day—maybe they are disinformation? Workers at crematoriums are reporting working round the clock doing 5 times the normal seasonal cremations—maybe they are just whiney, capitalist sympathizing recidivists? If you lie often enough, no one should have any reason to believe anything you ever say.

If you appreciate the quick assessment of Infectious Disease and Pandemic analysis please share with your friends. I asked my editor how to go out with the end of the year—she said Whimper, don’t risk a Bang. Thanks… it’s free, like bread in restaurants used to be.