New COVID-19 Variants Displace Stable BA.5 Variant, Could Change Transmission Rate

The disease burden for COVID-19 in Milwaukee County is holding steady, but new variants have begun to displace the currently dominant strain, potentially upending a period of relatively stable COVID-19 transmission.

The long-dominant subvariant of Omicron, called BA.5 is no longer the dominant form of COVID-19 in the U.S., making up less than 40% of cases across the U.S. as of Nov. 4. Broken down by regions, the data shows that in the Great Lakes states, the formerly dominant variant is responsible approximately 45% of cases. As of last week, the long-dominant Omicron subvariant still accounted for more than 50% of cases in the Wisconsin region and across the U.S.

This scenario, where the formerly dominant variant is displaced and the disease enters new, less predictable territory, has been the subject of warnings from public health officials for weeks now.

“As we see a substantial change in the variant landscape with BQ.1 and BQ.1.1 substantially displacing BA.5, we are reminded that the pandemic remains dynamic,” Dr. Ben Weston, chief health policy advisor for Milwaukee County, told Urban Milwaukee Friday. “Given that, it is important for everyone, but especially those over 65 to get their COVID bivalent booster.”

Public health officials have been urging vaccination and booster shots while the disease was stable, saying that population-level immunity was the best defense against a new mutation of the disease, as that mutation will bring with it new disease characteristics that cannot be predicted.

“Additionally, we are seeing an earlier than usual rise in influenza activity, which means that if you have not already done so, now is the time to get your flu shot,” Weston said.

In Milwaukee County, 61.6% of the overall population is completely vaccinated, according to a countywide vaccination report. Anyone six months or older is currently eligible for COVID-19 vaccination.

Among county residents eligible for a booster, 58.8% have received one. Eligibility for a booster dose includes anyone that is five years old or older and completed an initial vaccine series of Pfizer or Moderna as of June 3 or received a Johnson & Johnson vaccine on or prior to Sept. 1.

A countywide COVID-19 report shows disease levels holding relatively steady. In the past week there were 634 new cases of COVID-19 and 645 the week prior. When cases among children are isolated out, it shows there were 110 new cases of COVID-19 and 98 the week prior. The report, which covers Oct. 26-Nov. 1, is produced by epidemiologists, public health officials and faculty from the Medical College of Wisconsin and UW-Milwaukee.

There were 129 people hospitalized due to COVID-19 this past week and two deaths.

The positivity rate, which measures the percentage of tests that come back positive for COVID-19, was 9.3% this past week. This figure only includes PCR laboratory tests and does not include rapid-antigen or at-home tests.

Read the full weekly, children’s and vaccination reports on Urban Milwaukee.