The Omicron BA.4 and BA.5 strains of the COVID-19 virus are becoming dominant around the nation, and a local doctor said they may be responsible for the spike in cases in Butler County.

According to the Centers for Disease Control and Prevention, nationally, about 85 percent of positive COVID-19 cases from July 24 through 30 were from the BA.5 strain.

Dr. John Love, executive director of clinical safety and infectious disease at Butler Health System, said BA.4 and BA.5, which are actually strains of the Omicron variant, became dominant sometime in July.

While the new strains have been creating a higher risk of community transmission, Love said the number of hospital patients is still much lower than what was seen in the Delta and Omicron surges that started last year. Additionally, the number of people in the area who are vaccinated against COVID-19 means the chances of death or health complications is lower overall.

“Your vaccination may have varying abilities to recognize that altered protein,” Love said of the BA strains. “The vaccines are probably not going to give you the super robust protection like it did for the first virus; it may not keep you from getting sick, but it may reduce the risk of you ending up in our hospital wards — and that's still a win.”

Butler Health System reported Monday that Butler Memorial Hospital had 18 inpatients with COVID-19, which was up from the previous week, when there were 14.

Love said all inpatients are tested for COVID-19 when they are admitted to the hospital, so some patients visit the hospital for a particular ailment, then find they have COVID-19. If they test positive for the disease, patients are placed in private rooms, and hospital staff members take extra precautions when interacting with them, according to Love.

Companies are working on vaccines to provide protection against Omicron strains, which Love said could come in the form of booster shots.

“We’ll have to wait and see if that comes to fruition and what that looks like,” he said.

Love also said that the prevalence of at-home COVID-19 tests has created a “blind spot” in national data, because most of those tests are not reported to the Department of Health or CDC.

So the CDC requests data from sites around the country to see what sequencing is contained in positive tests to determine what the most common variant and strain is in a region.

“You can see the rise of certain variants over time, and BA.5 has been kind of ascending for a bit,” Love said.