From the co-founder of the COVID Tracking Project, Erin Kissane:
On and around major holidays, thousands of people whose labor makes testing and data-reporting pipelines function go home. As a result, testing slows, and reporting through the various levels of public-health agencies tanks, along with the last-mile work of getting the data into public view.
This effect produces the illusion that cases are dropping, or are dropping faster than they are—and tragically, this false decline in the numbers comes just as the risk of transmission increases, because holidays also involve a rise in large get-togethers with friends and family.
Later, when people return to work and crunch through testing and data backlogs, the data will recover (though only to a limited degree; lots of people who couldn’t get a test because of shortages and holiday slowdowns simply won’t ever get one).
The sudden arrival of the backlogged data will in turn produce a deceptively sharp spike that looks like an even more sudden increase in cases. With two major holidays in a row, the artificial drops and spikes produced by reporting delays can run together, creating a long period of confused data. Last year the COVID Tracking Project at The Atlantic found that after the twin disruptions of Christmas and New Year’s Day, holiday data distortions extended for weeks into the new year.
The Atlantic
As the Omicron variant sprints to dominance across the United States, the country’s ability to track the resulting infections is about to evaporate. CDC rules specify that the only way a COVID-19 infection gets counted as a confirmed case is if it’s identified via PCR test or genomic sequencing. Booked-up testing sites and clogged test-processing labs—and the necessary shift toward rapid antigen tests, which can’t officially confirm a case even when their results are reported to public-health authorities—mean that many infections simply won’t get counted.
“The result of these cascading testing and data problems is that just as Omicron transmission really takes off in the United States, the large-scale movement of the pandemic is becoming impossible to discern, while at the scale of the individual, millions of people will be unable to know whether they have COVID. Case numbers will be artificially reduced, along with testing counts. And, at the same time, many people will be unable to get the rapid tests required to tell whether they’re likely to be infectious.“