More than 150 cases of delta variant found in Mass., according to the DPH

Experts say the answer to the arrival of the delta variant in the United States is for people to get one of these: a coronavirus shot.Craig F. Walker/Globe Staff

The Department of Public Health says more than 150 cases of the worrisome delta variant of the coronavirus have been found in Massachusetts.

National laboratories contracted by the US Centers for Disease Control and Prevention to conduct genomic surveillance have identified the cases, the department said.

The findings were from samples collected here as early as March 13 and up until May 23, the DPH said.

The DPH noted that the CDC still considers the delta, which was first detected in India, to be a variant of interest, not a variant of concern, which is a more urgent category.

But experts and officials have been expressing worries recently, saying the delta variant is believed to be more transmissible — and may also make people sicker.

Dr. Anthony Fauci, President Biden’s chief medical adviser for the pandemic, said Tuesday that the delta variant “may be associated with an increased disease severity such as hospitalization risk.”

Fauci said the variant is “rapidly emerging as the dominant variant” in Great Britain, accounting for more than 60 percent of new cases. “It’s essentially taking over” there, Fauci said at a White House coronavirus response team briefing. “We cannot let that happen in the United States.”

He also said that in the United States, the variant is already accounting for more than 6 percent of new cases.

Experts say the Moderna and Pfizer vaccines currently in use in the United States are effective against the delta variant. There is not enough data yet on the Johnson & Johnson vaccine, Dr. Shira Doron, an infectious disease physician and hospital epidemiologist at Tufts Medical Center, said Wednesday in an e-mail. But she noted “the AstraZeneca vaccine, which uses very similar technology, appears to be protective.”

The delta variant may cause outbreaks in places where fewer people are vaccinated, experts and officials say. They say its arrival underscores the need for as many people as possible to get vaccinated.

Massachusetts is a national leader in vaccinations, with more than 4.5 million people having gotten at least a first shot, and nearly 3.9 million fully vaccinated as of Wednesday.

“There’s clearly evidence of spread of the delta variant in Massachusetts,” said Dr. David Hamer, a physician at Boston Medical Center and a Boston University epidemiologist, calling it a troubling development. But, he said, “As long as we keep pushing to get high levels of vaccine coverage, it may not take off.”

“The arrival of the delta variant is a reminder that our health perspective needs to stay global as part of tackling COVID-19 at the national and state levels. Its troublesome presence represents yet another motivation to accelerate vaccination efforts for communities everywhere,” Dr. Howard Koh, a former assistant US secretary of health who is now a professor at the Harvard T.H. Chan School of Public Health, said Thursday in an e-mail.