Island health agents reported 24 positive Covid-19 tests last week — the largest number since late May, with a significant percentage coming among fully vaccinated residents.

In a weekly update, health agents said that of the 24 new positive cases, 10 are among fully vaccinated residents, one among partially-vaccinated residents and 11 are among unvaccinated residents.

In a further update Monday, health agents added more cases from Sunday and Monday, with three positive cases and one probable case reported on Sunday, and eight new cases reported on Monday.

Altogether, the Martha’s Vineyard Hospital has tested 24 of the cases, while eight came from TestMV, one came from Aquinnah tribal testing and two from other providers.

The 24 cases reported between July 25 and July 31 come after Island case tallies dropped to zero during the first week of July.

But case counts have climbed in the month since, with the Delta variant detected on the Island and health agents issuing a mask advisory for indoor public spaces as summer continues. The mask advisory does not apply to private homes, but is focused on crowded retail shops, Tisbury health agent Maura Valley said.

According to the report, four test samples have been positively sequenced for the variant on the Island, with an additional two samples coming back “indeterminate” from the state epidemiology lab.

All three vaccines have been shown to significantly reduce severe cases of Covid-19, although vaccinated residents can still become infected by the virus. Symptoms are generally much milder among vaccinated residents, studies have shown. 

Using information from the earlier report, of the 50 new positive Covid-19 cases reported since July 11, 22 — or 44 per cent — have come among vaccinated individuals. Another 21 — or 42 per cent — have come among unvaccinated individuals. The other cases are unknown, according to health officials.

The 24 cases from last week span all ages and genders, with three among children 10 or younger, one among people 11 to 19, four among people in their twenties, three among people in their thirties, three among people in their forties, six among people in their fifties, three among people in their sixties and one among people 70 or older.

There are no patients currently hospitalized with the virus, according to the Martha’s Vineyard Hospital website.

The Island has now reported 1,572 confirmed positive PCR cases since the pandemic began. No residents have died from the virus.