Data Snapshot: Has winter passed? Covid-19 wastewater update in 5 major US cities.
A seasonal picture may be emerging. What does this mean for future boosting?
Coronaviruses are seasonal, typically peaking in the winter months. Is SARS-CoV-2, the coronavirus that causes Covid-19, also destined to become seasonal? It’s possible, and likely. In fact, case and mortality data from the Covid-19 pandemic have already hinted at this, with massive waves in the first two winters in the US.
But so far, the virus had not demonstrated slam-dunk seasonality, in part because of our own behaviors and the appearance of new variants prior to a time when a majority of the population had acquired any of immunity to it. For example, Delta erupted in the summer of 2021 in the US. That variant was so contagious that it caused a huge wave in the summer. Omicron may have “finished us off” last winter in terms of turning the immune-naive (i.e., people who have never been vaccinated or infected) into rarities. The question—now that most people’s immune systems have seen the spike protein of SARS-CoV-2—is whether we can we expect a more predictable seasonal pattern. Time will tell.
Okay, but have we at least emerged from the third winter in the US? Today is March 13th, 2023, and while it’s impossible to know, wastewater data certainly suggest that winter waves have crested and receded in 3 successive years here. Take a look at wastewater data for five large US cities during the pandemic
.
Now look at just this past late fall and winter (up through last week).
Why does this matter? For one thing, since the pandemic started, I’ve been saying that we might want to consider masking and/or routinely testing in some settings during the late fall and winter (i.e., nursing homes, other crowded settings, etc) in the future. Second, if the effects of annual boosters last only 3-4 months (with waning starting as early as 4 weeks), it might make sense to roll out annual boosters not in the early fall, but instead waiting until November or even December, as some have suggested for flu shots.
Thanks to Benjy Renton for curating Data Snapshot.
Data: Boston: https://www.mwra.com/biobot/biobotdata.htm
Chicago: https://iwss.uillinois.edu/
Los Angeles: https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/COVID-19/CalSuWers-Dashboard.aspx
New York City: https://data.cityofnewyork.us/Health/SARS-CoV-2-concentrations-measured-in-NYC-Wastewat/f7dc-2q9f/data
San Francisco: https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/COVID-19/CalSuWers-Dashboard.aspx
Is there any possibility of boosters twice a year instead of just annually? Maybe not for everyone, but just people at higher risk of severe illness.
This is off the point of the very helpful post on waste water: Masks have become optional in healthcare settings in my state--Rhode Island--and as CDC guidance is tied to case numbers--which represent a fraction of circulating virus--many facilities have gone mask optional. My husband was in for an urgent X-ray today and it was like going to a grocery store.
Going to a large healthcare facility today, few were masked--including providers. I sure wish that healthcare would make provisions for people who are at risk.
And re: boosters--they're being offered in the UK to immune compromised people, people over 75 and people in NH/care homes. Wish we had an option for boosters here.