Are New Variants Causing an "Invisible" Wave?
A recent piece in The Atlantic suggests we could be in the middle of an "invisible" wave. It puts me in mind of the tree-fall-in-the-forest conundrum.
In the U.S. our case surveillance systems have always been crappy because they rely on self-selected participation rather than random sampling. The two approaches can give very different pictures of infection rates.
Worse, now we are not even getting an accurate count of the self-selected tests. This is for two reasons. First, people are having milder cases and they may not even recognize they have COVID-19, or may not be seeing physicians if they do.
Second, people have ready access to in-home antigen tests. I have noted before that those are of questionable accuracy, especially for asymptomatic infections. So people could have a false negative test and go about their business unknowingly spreading the disease.
But even if they get a positive test there is (as far as I know) no way to report it to authorities. This is causing public health experts like Zeke Emanuel, vice provost of global initiatives at the University of Pennsylvania, to say things like "I do think we are in the middle of a surge, the magnitude of which I can’t tell you."
There are proxy measures like wastewater surveillance, but implementation is spotty. For example in Arizona there are only a few counties doing it, and they don't include Maricopa County, the largest with 60% of the state's population.
Another indicator that is better than case rates is test positivity. But that suffers the same problem of self-selected samples.
This is concerning because, according to an article just published in the Washington Post (sorry, paywalled) SARS-CoV-2 continues to evolve apace. While we are worrying about omicron sub-variant 2, scientists have now detected more, up to sub-variant 12 BA.2.12, along with BA.4 and BA.5!
The article suggests there is plenty of evolutionary space left for the virus to "explore" and that future variants will evolve to me more contagious and better able to evade immune responses. One guy speculates that it is approaching and may achieve the same level of contagion as measles.
So we simultaneously are lowering our antennae, and the virus is continuing to evolve. If it becomes more deadly as well we could be in for yet another wave. I don't think people will respond well to that.
