‘Concerning’ Delta COVID Variant Has Been Spreading in Mass. Since April: Expert

As of early June, the Delta variant accounted for about 7% of positive samples that have been sequenced in Massachusetts

The more contagious Delta COVID-19 variant, first identified in India, has been in Massachusetts for weeks now and is steadily rising, according to experts.

Now the dominant strain in the U.K., the variant is responsible for an estimated 60% of new cases. It’s more prevalent than the Alpha strain, formerly called the B.1.1.7 strain, which was first identified in the U.K., and transmission is peaking in people between the ages of 12 and 20, White House chief medical advisor Dr. Anthony Fauci said at a press briefing Tuesday.

The variant has been “steadily rising” since it was first clearly found in Massachusetts during the second week of April, according to Dr. Davidson Hamer, professor of Global Health and Medicine at Boston University Schools of Public Health and Medicine.

As of early June, the variant accounted for about 7% of positive samples that have been sequenced in Massachusetts, according to GISAID.

More than 150 cases of the delta variant were identified between March 13 and May 23, according to the Massachusetts Department of Public Health, which referenced data provided by U.S. Centers for Disease Control and Prevention from the national laboratories.

First detected in October, the Delta variant has spread to at least 62 countries, the World Health Organization said last week.

“The gradual rise in Delta is concerning,” Hamer told NBC10 Boston. “There is limited evidence from outside of the U.S. that this variant of concern is more transmissible and potentially can cause more severe disease.”