BA.2 has taken over New England.
The Covid-19 variant, Omicron’s close cousin, now forms about 84% of cases in the region, according to U.S. Centers for Disease Control and Prevention data.
New England’s case counts have risen as a result, with Vermont in particular now reporting the second-highest case rates in the nation, according to The New York Times. The latest research suggests BA.2 is more transmissible than the Omicron variant, but about equally likely to cause severe illness.
Measuring BA.2’s impact on Vermont is challenging. The meaning of state data has changed as Vermont transitions to an “endemic” mentality in its data collection and shifts its Covid testing strategy.
Here are the data points available to assess BA.2’s impact, and what they could mean in the context of a new Covid outlook.
Cases, testing and percent positivity
The number of Covid-19 cases reported each day no longer points to a clear and consistent trend, since self-administered antigen tests have surpassed PCR tests as the main way that Vermonters get tested for the disease, and not all those results are reported.
In fact, Vermont now provides antigen tests and LAMP tests along with PCR options at its state-run testing sites, but the majority of cases reported by the Department of Health continue to be PCR results.
The state reported 150 cases Tuesday for a seven-day average of 150.3, about 16% higher than last week, according to the health department. At the same time, the PCR positivity rate has risen to 7.2%, the highest it has reached since early February.
“With at-home tests being used more frequently, we are less reliant on case reporting to assess levels of virus activity,” Vermont state epidemiologist Patsy Kelso said at a press conference Tuesday.
Self-reported antigen tests
The health department also reports separate data on Vermonters who reported their antigen test results to the state. That number has ticked up in recent weeks.
The health department said it had received 516 positive antigen test results in the past week, compared to 421 positives in the prior week and 247 the week before.
“It reflects what we think we're seeing through other data — that Covid is still around. The risk is not zero,” Kelso said.
Gov. Phil Scott said the expectation was never that Covid would just “disappear.”
“Covid is here to stay for a while and we just need to learn how to manage it,” he said. “And from the very beginning, it was about managing our health care system. So far, I think we're not surprised by any slight increase" in the latest case data.
Hospitalizations
Covid’s burden on the health care system remains low so far in the BA.2 era. The health department reported 22 people were in Vermont hospitals with the virus as of Tuesday, including two patients in intensive care.
That’s an increase from only 12 hospitalizations on March 25, but still far below the record-breaking two-week streak of over 100 ICU Covid patients in January. The Department of Financial Regulation also reported that new hospital admissions for Covid remain low, at about four per day.
Kelso said hospitalizations tend to be a “lagging indicator,” and the state “needs to keep an eye on that.”
“But given that BA.2 has been in Vermont for a number of weeks, and we've not seen a significant uptick, I'm hopeful that while Covid is still around, we won't see a dramatic surge and we won't see an increase in hospitalizations to the point that strains the health care system,” she said.
Vermont reported one additional death on Tuesday, for a total of 620 deaths throughout the pandemic. The rate of deaths remains below one a day.
Wastewater testing
Five Vermont municipalities test their wastewater to measure the proportion of Covid viral samples, but their data reporting methods are inconsistent and unstandardized.
Four of those communities — Brighton, Springfield, St. Albans and Winooski — report their data to the CDC, while Burlington reports its data on its own dashboard.
The latest data from Springfield shows that the percentage of Covid samples in its wastewater is going down, while Burlington has reported a recent uptick in its viral samples at two treatment facilities.
At a press conference on March 29, Health Commissioner Mark Levine said officials are still working on how to use wastewater data.
“We’re just trying to learn how to aggregate the data appropriately and interpret it and make sure that people are appropriately led by it, as opposed to misled by it,” he said. “So, more to come.”
