Cases of Covid-19 began creeping up on the Island again this week, with 20 new cases confirmed since Saturday, including 10 on Thursday alone.

Meanwhile, Martha's Vineyard Hospital said they would open 606 more appointments for third-dose Covid-19 vaccine shots on Friday at 3 p.m. People 65 or older who have had two previous Pfizer doses and people with compromised immune systems are eligible to make appointments for Tuesday, Wednesday or Thursday in each of the next two weeks.

Signups are available on the hospital website, or by going to  https://covidvaccine.massgeneralbrigham.org/.

As of Thursday, 307 people had received third-dose booster shots from the hospital. Moderna and Johnson & Johnson are seeking emergency authorization from the Food and Drug Administration to provide booster shots, but only the Pfizer vaccine  has been approved  to date.

Covid cases had been declining on Martha's Vineyard for several weeks, but began to inch up again last week, with the Island boards of health reporting 11 new cases of Covid-19 for the week ending Saturday, Oct. 2, up three from the previous week. Ten more new cases were reported between Sunday and Wednesday, then 10 more on Thursday.

In the latest weekly report issued Monday, health agents said two of the 11 cases for last week were children under 11, one was a child between 11 and 19, six were adults between 20 and 39 and two were adults between 60 and 69. Five were people who were fully vaccinated, five were unvaccinated individuals and one was unknown.

The boards of health report said seven of the cases last week were diagnosed by PCR tests taken at Martha’s Vineyard Hospital, three were from TestMV and one from another provider. Ten of the cases were symptomatic and one was unknown. One additional probable cases was reported from an over-the-counter test.