Data: CDC; Note: Data for the two most recent weeks may be incomplete due to delays in reporting; Chart: Alice Feng/Axios
California has high levels of COVID-19 heading into the holiday travel season, according to recent data by the CDC.
Why it matters: While many Americans by this point have some combination of natural and vaccine-induced immunity, COVID can still make people plenty sick and force them to miss school, work (if they can) and holiday activities.
It also remains a potentially fatal threat for vulnerable groups, like the elderly and immunocompromised.
The big picture: As of early December, 22 states had "very high" COVID-19 wastewater levels as defined by the CDC, which compares current rates to baseline measurements at sites nationwide. (Read more about the agency's methodology here.)
Many of the states with "very high" levels are concentrated in the Midwest and Mid-Atlantic, while California is listed as "high."
Of note:Wastewater analysis is one of the best methods for tracking the spread of COVID-19 these days, given how few people are testing and how few of those results are reported to local or state health officials.
Yes, but: It's a relatively new method of tracking contagions that's still getting fleshed out.
The bottom line: All that said, there's enough data here to pretty clearly show a worsening COVID-19 situation nationally — especially when considered alongside other metrics, like hospitalizations, which are rising in many of the places with "very high" wastewater rates.