After more than 100 Island high schoolers called in sick on Wednesday — including 10 football players, 10 members of the boys’ soccer team and the cheerleading coach — Saturday’s football game and the season’s final two soccer matches were canceled, beginning a cascade of sports suspensions and other precautions as cases of suspected H1N1 flu spread quickly among Vineyard youths.

Meanwhile the Martha’s Vineyard Hospital yesterday received 500 doses of H1N1 vaccine, enough to hold a free clinic there on Saturday morning for children six months to five years old who are not enrolled in Island schools, according to hospital development director Rachel Vanderhoop.

People under 24, pregnant women and people with underlying illnesses are considered highest priority for the vaccine, which remains in short supply due to slower than expected national production and distribution.

“We are not considering closing the school yet,” Vineyard schools superintendent Dr. James H. Weiss said on Wednesday. “We are monitoring [the spread of the H1N1 virus] and the question is, can we function? Yes. Six-sevenths of the kids are there, all but one staff member are there.”

In-school vaccination clinics are planned across the Island, though no dates have been set. The Vineyard Nursing Association, coordinating vaccine orders for all town boards of health and the tribe, is awaiting delivery of enough H1N1 vaccine to provide for all Island school children whose parents wish them to have it, said executive director Robert Tonti.

So far, the VNA has used its first 100 doses of H1N1 vaccine to vaccinate its health care staff and emergency medical workers with direct patient care. A second batch of 100 doses arrived yesterday, Mr. Tonti said, and a decision as to who would get those would be made today or Monday depending on a consensus among the Island officials. Half of those doses are injectable and half are mist (which cannot be used by pregnant women, children under two, adults over 50 and some medically fragile people).

“I don’t want to hold it,” Mr. Tonti said. “We want to be as aggressive as we can.”

The state is not testing widely for the virus, advising doctors and patients to assume flu-like symptoms mean H1N1, as it is not yet seasonal flu time. “Our sense is, this is [H1N1] flu and it is spreading quickly,” Mr. Tonti said.

Some parents already have had their children vaccinated through their pediatrician or primary care doctor, though not all Island doctors have received a supply of vaccine. Town health agents are available to assist individuals who require a vaccine.

A vaccination clinic for seasonal flu is set for Wednesday, Nov. 11 at the high school, though anyone arriving by car will have to first register at another site, either Waban Park or the Agricultural Hall. Forms are available at town halls or Web sites to be prepared in advance.

Parents of preschoolers are encouraged to download and complete one form for each child from the hospital’s Web site, mvhospital.com, before the preschool H1N1 vaccination clinic tomorrow, Oct. 31, from 9 a.m. to 1 p.m. However, no preregistration is required and forms will be available at the clinic.

The hospital already has reached out to high-risk populations, Ms. Vanderhoop said. More than 65 pregnant women had been vaccinated, which Ms. Vanderhoop described as a good response rate. “And we have been working hard to get our frontline employees vaccinated,” she said, “and we are just about done with that.”

By yesterday, absences at the high school had dropped to 80 (of more than 700 students), with potential flu cases at around 30, but cross country practice and meets had been suspended. A sixth runner reported being ill, bringing the team to the 20 per cent threshold the school is using to determine sports suspensions, according to regional high school principal Stephen Nixon.

“We have noticed that if one or two students get ill on a team, it either stalls at that number or jumps within a day or two to 20 per cent of the team; that is how we have determined the cutoff figure,” he wrote on the school Web site.

The Sandwich girls’ field hockey team forfeited yesterday’s match rather than come to the Island, although they would host the Vineyard girls’ soccer team at Sandwich yesterday afternoon. Falmouth’s junior high footballers were game to play on the Vineyard yesterday.

Among Island elementary schools, Mr. Weiss said Wednesday there was one confirmed case at each Edgartown and Tisbury school, two in West Tisbury, and five or six cases at the Oak Bluffs elementary school; many were siblings of flu-stricken high schoolers.

Mr. Weiss said only one faculty member, cheerleading coach Becky Cass, was ill. He knew of no severe cases that had required hospitalization.

Already on Monday, Mr. Nixon had sent home a letter to parents alerting them to a number of confirmed H1N1 flu cases in the school. He relies on parents to confirm whether swine flu is the cause of illness; as of Monday, he knew of less than 10 cases. “But other kids who’ve left have been symptomatic,” Mr. Nixon said in an interview.

Wednesday was a half-day at the regional high school due to parent-teacher conferences, and a rainy day, so Mr. Weiss suggested that students might have been less likely than usual to turn up. “And that is a good thing,” he said.

Vineyard school officials continue to advise anyone feeling unwell, particularly showing symptoms such as fever or cough, to stay home.

Even churchgoers are being advised to stay home if they are sick. Fall River diocese Bishop George Coleman this week reminded Catholics they were not obligated to attend mass if they suspect that they are ill, particularly with a contagious illness.

The bishop also ordered priests to suspend communion wine from the cup. Father Michael Nagle, pastor of the Vineyard’s Catholic congregation, said yesterday there also would be no contact at the sign of peace.

“Instead of a handshake, we can wave or bow, just acknowledge each other,” he said. “I think everyone will understand, it’s just common sense for the cold and flu season to keep people healthy.”

Hand sanitizer already is available at the church entry, and Sunday school children are given some before using materials in their classrooms.