COVID variant detected in region
Researchers at the University of Pittsburgh have detected a new omicron subvariant in Western Pennsylvania.
Known as BA.4, it has been designated as a variant of concern by the Centers for Disease Control and Prevention. While COVID-19 cases are climbing in Allegheny County, the new variant is not seen as responsible for the increase.
Using an in-house test developed to find new variants, the Pitt scientists identified BA.4 in a sample taken in mid-April from a patient at the University of Pittsburgh Medical Center. It’s the first known case of BA.4 in Western Pennsylvania. The researchers published the findings May 9 in the Journal of Medical Virology.
This week, BA.4 and a similar omicron subvariant known as BA.5 were reclassified as variants of concern, up from variants of interest, by the European Centre for Disease Prevention and Control. Both BA.4 and BA.5 were first detected in South Africa in January and have since become dominant variants there.
“We assume that the virus probably traveled here,” said Dr. Alan Wells, a professor of pathology at Pitt and senior author on the paper.
In a May 13 update, the European agency said the growth of BA.4 and BA.5 in South Africa is likely due to their ability to evade vaccine-induced immunity and natural immunity. Early evidence indicates that unvaccinated individuals who have experienced an infection with the original omicron variant, BA.1, can be reinfected with BA.4 and BA.5. While vaccinated individuals appear to be better protected, immunity against omicron and its subvariants seems to wane over time.
The update went on to say that the variants “could cause a significant overall increase in COVID-19 cases” in Europe in the coming weeks and months.
In the United States, BA.4 is not yet one of the major circulating variants.
“I wouldn’t worry too much about this one yet,” said Dr. Wells. There’s no indication that BA.4 and BA.5 are more severe compared to other omicron subvariants.
However, as more variants arise, he said, it’s likely that they will get better at evading our current COVID-19 vaccines. Already, several monoclonal antibody drugs have been rendered ineffective as the coronavirus has evolved.
“I think the lesson is, we really have to make sure our vaccine strategy keeps up with variants,” said Dr. Wells. He added that nextgeneration vaccines that target multiple variants may be able to provide better, longer-lasting protection.
COVID-19 cases are once again increasing in Allegheny County, but they’re being driven by the BA.2 and BA.2.12.1 omicron subvariants. According to limited sequencing data, BA.2 accounted for about 68% and BA. 2.12.1 accounted for about 28% of positive COVID-19 cases in the week ending April 30.
For the week of May 12-18, there were nearly 3,732 new infections reported in Allegheny County, up from 2,761 new infections reported the week of May 5-11. It’s the second week in a row that cases have gone up by nearly 1,000.
There were 76 hospitalizations and two deaths reported the week of May 12-18.
Concentrations of the coronavirus in wastewater samples have also continued to increase — between 2% and 8% daily from the first to second week of May.