Covid-19 cases on the Island are trending downwards, but Dukes county continues to have the highest positivity rate in the state, according to data from the state Department of Public Health.

Tisbury is currently the only town in the commonwealth considered high-risk for Covid 19 spread.

At a hospital briefing Wednesday morning, chief nurse and head of operations Claire Seguin noted the high positivity rate, pushing for more vaccines in the runup to summer. Vaccines are now available for all Islanders 12 and older.

“The virus is very present here on the Island. Our positivity rate compared to the state is quite startling,” Ms. Seguin said. “Now is the time to get your vaccine. We have plenty of appointments and an ample supply.”

Island boards of health reported 26 new cases between Saturday, May 22 and Saturday May 29, a notable decrease from last week’s case counts. In an email to the Gazette Tuesday, Tisbury health agent Maura Valley said no new cases had been reported since Saturday.

Of the 26 new cases, 19 were tested at the hospital, four at TestMV, two from the tribe’s testing program and one from another provider. Twelve cases were symptomatic, nine were asymptomatic and five were unknown, the board of health report shows.

Continuing a trend that has seen a higher proportion of young people and children contract the virus, eight — or 31 per cent — of last week’s cases were identified in the 0-10 year old age group. Vaccines are only currently eligible for people ages 12 and older.

This week’s case load also marks the lowest weekly case count since the virus surged in early March. In the past three weeks the boards of health have reported 32, 33 and 55 cases respectively.

But even as Island Covid numbers drop, county case rates remain highest in the state. A weekly report from the state DPH last Wednesday found Dukes and Nantucket counties had the highest average incidence rate reported in the commonwealth in the past two weeks, with 22.6 cases per 100,000 — and a 5.28 per cent positivity rate. Hamden county had the second highest average at 9.5 cases per 100,000.

Tisbury remains the sole town designated high risk for the spread of Covid, with 30 cases reported over the past two weeks and a 6.86 per cent positivity rate, according to recent DPH data. In January there were over 200 communities considered high risk for Covid spread.

At the hospital briefing, Ms. Seguin pointed to reasons for Tisbury’s high positivity rate, saying that the Island’s comprehensive testing and contact tracing has revealed a significant number of positive cases that otherwise might have gone unnoticed. But she also pointed to subtler factors.

“It could be related to folks living in close quarters, where the virus can easily spread when people are not vaccinated,” Ms. Seguin said.

Oak Bluffs and Edgartown are also considered moderate risk for virus spread, with 20 cases and 24 cases respectively over the past two weeks. Remaining towns across the commonwealth are either ranked moderate or low risk for the spread.

Ms. Seguin also reported that no new virus variants had been detected on the Island, after samples were sent to the state lab for investigation.

“No news is good news,” Ms. Seguin said.

Meanwhile, as cases rates continue to lead the state, so too do the Island’s vaccination numbers. According to data from the weekly state report released on May 27, 84 per cent of total Dukes County residents have been fully vaccinated, compared with 68 per cent statewide.

The state is also now reporting the percentage of eligible residents (people 12 years and older) who have been vaccinated. Dukes County leads the commonwealth, with 95 per cent of eligible residents having received at least one dose of vaccine, and 77 per cent of eligible residents receiving both doses.

Barnstable county has the second highest rate with 78 per cent of eligible residents receiving at least one dose.

As of last Thursday, the hospital had administered 13,031 first doses, including 11,469 completed vaccinations.

Trying to square the high positivity and vaccination rates, Ms. Seguin said at the briefing that she believed the Island population was undercounted in census numbers, especially as population rises moving toward summer.

“The population on the Island is underrepresented, especially as we head into the warmer weather,” Ms. Seguin said.

The hospital plans to continue its vaccine clinics throughout the summer, adjusting hours based on demand. Ms. Seguin said the largest gap in vaccinations was among the Island’s 20-29 year-old-population. Whereas 95 per cent or more of the Island’s other age demographics have received shots, only 79 per cent of people in their 20s have been vaccinated.

Ms. Seguin encouraged them to schedule appointments.

“We met our deadline of being able to offer everyone on the Island an appointment. We wish more people took us up on this opportunity,” she said. “We do plan on hosting clinics throughout the summer.”

The Yankee mobile vaccine bus is also set to return to the Island June 5 through June 9.

Noah Asimow contributed reporting.