The most important trend I see this week is that viral concentration in wastewater in Hampshire County is down. We are not quite past "holiday hours" affecting testing, given that the 14 day averages span from Dec 25th to Jan 7th, although they are also starting to reflect a decrease. Importantly, the 7-day average percent positivity is decreasing - that's a sign I look for that we're starting to get back to "pre-holiday" testing levels.
Hampshire County is still in the medium risk category based on hospitalizations, and weekly admissions are still trending upwards. That's not unexpected - hospitalizations always lag behind infections, so it will be another week or two before those hospitalizations follow. Hopefully this is the start of coasting down the other side of the holiday uptick.
Biobot Analytics is able to test specifically for XBB variants now - last week, just over 40% of the virus in the wastewater in Hampshire County was a result of an XBB variant. This category includes XBB and XBB 1.5, which is our most contagious variant circulating and is quickly becoming dominant. Last week I made some guesses about how prevalent XBB 1.5 is in Hampshire County and what role it might be playing in the holiday increase in cases. The CDC estimates that XBB 1.5 is responsible for just over 80% of infections in the Northeast region. I'm not entirely sure why there is a difference in XBB 1.5 prevalence between the Northeast as a whole and Hampshire County specifically. I do think it means that there is the possibility that it means we haven't felt the full effect of XBB 1.5 locally.
I realize that's a bit of mixed messaging - there are promising signs in the data but I'm keeping a wary eye on what's going on with XBB 1.5. Given this context, my advice to folks who are high risk or spend time with others who are high-risk is to continue to implement risk mitigation strategies for the time being, rather than relaxing now that infections seem to be declining.
Finally, I've seen misinformation circulating lately about the vaccine, and rather than addressing vaccine safety here again, I'll refer us back to past dashboard updates and an excellent summary of the research by Your Local Epidemiologist (https://yourlocalepidemiologist.substack.com).
Stay well,
Megan W. Harvey, PhD (she/her)
Epidemiologist
