Editor’s note: The following Tri-Town Health Department update was written by Amy Hardt, MPH BSN RN, Lead Public Health Nurse at the Southern Berkshire Public Health Collaborative, and sent out Monday, March 21. It has been edited for clarity.
A note from Amy Hardt: This post will be shifting from weekly to biweekly for the near future. If conditions change substantially, it will go back to weekly.
As you can see from the dashboard, reported cases last week in southern Berkshire dropped again by a lot (-42%). We had seen a major uptick in PCR testing the previous week, but that was likely due to many folks presenting with symptoms from other respiratory viruses going around. Last week’s testing numbers were back down again, as expected (-41%). In Berkshire County overall, both PCR cases and testing went down again as well (-25% and -27%, respectively). We remain in the CDC’s Green/Low community impact zone.
While our sub-County/County dashboard has so far not included other regional indicators such as wastewater surveillance trends, antigen lab data, or nearby city case data, it is worth noting that there have been small upticks in each of these around the Northeast over the past week or so. Time will tell what this means for Berkshire County and Massachusetts cases overall. Bottom line: Don’t throw those masks out just yet and keep a supply of (free!) rapid tests at home.
This week’s center graphic is a CDC chart showing the current state of COVID-19 subvariants in the Northeast. There’s been a lot of news coverage lately about the Omicron subvariant BA.2 and its role in driving an uptick in cases around the world. In our region, we have not (yet?) seen the same effect. While BA.2’s portion of new reported COVID-19 cases in the Northeast has grown over the past 5 weeks from 5.6% to 38.6%, this increase is nothing like what happened in December–January. During that time, Omicron B.1.1.529 outpaced the Delta variant much more rapidly, increasing from 1.6% to 95% of all cases over a 5-week period.
While BA.2 is observed to be more contagious than B.1.1.529 and will surely become dominant at some point, the dynamics are different this time. The likely cause? According to the World Health Organization’s review of recent data, immunity derived from Omicron B.1.1.529 infection appears to be protective against re-infection for several months — not only against getting B.1.2.529 again, but also against BA.2. This was unfortunately not the case for all those who had recovered from a Delta infection, and then found themselves infected again with COVID after exposure to Omicron.
So, the extension of natural immunity across the main Omicron subvariants so far is excellent news. But what does the rise of BA.2 mean in general? For folks who were not infected during this last Omicron surge, it means they likely remain vulnerable to infection with BA.2. This is especially true for those who are unvaccinated, or who had their last shot of the primary vaccine series more than 4 months ago but have not been boosted. And recent studies from other countries indicate that even those of us who have been boosted are protected against BA.2 infection only by about 40% one month after their shot. But that’s better odds than not being boosted. And fortunately, vaccine and booster protection against severe disease and hospitalization remains extremely high.
In Europe, we have seen more effective household spread than ever before with Omicron BA.2. If you do have someone at home who is at risk for severe COVID disease, especially if they are 65+ and have multiple comorbidities, reducing your chances of bringing COVID-19 home should still be on your mind. And getting a booster shot for everyone in the household who is eligible should be a priority. A second booster may soon be approved for seniors, which will also help protect them against infection and severe outcomes. Hopefully within the next month or so, vaccinations for young children will be available to help protect them and reduce household transmission, as well.
