Illness presumed to be swine flu has resulted in the absence of an average of more than 100 students each day of the past week from the Martha’s Vineyard Regional High School.

And still there is no indication of when Island health authorities will receive enough vaccine to inoculate all Island school children against the disease, much less the broader population.

A start has been made on inoculating those at greatest risk, including pregnant women and health workers. Last Saturday the Martha’s Vineyard Hospital vaccinated about 500 people, 450 of them preschool age children. And there will be clinics at three Island elementary schools, Chilmark, West Tisbury and Martha’s Vineyard Public Charter School, on Monday.

Those schools were selected simply because there was only enough available vaccine to do them at this time.

But there is no indication yet when other school populations might be vaccinated, simply because there has been no word from the state Department of Public Health as to when more supplies might become available.

Not only is the vaccine against the H1N1 virus, which affects predominantly younger people, in short supply, so is vaccine against regular seasonal flu, which presents a greater threat to older people.

Less than 60 per cent of the amount of the seasonal vaccine originally requested for a clinic to be held next Wednesday, Nov. 11, at the high school, has been received. The clinic will go ahead anyway, on a first come, first served basis. It is limited to people aged 18 and over.

But it is swine flu, which is assumed — in the absence of definitive tests — to be the more pressing problem at the moment.

And it is the high school which has been most seriously affected.

School principal Stephen Nixon yesterday traced the outbreak back two weeks, to when he received word from two parents who had taken their children to the Martha’s Vineyard Hospital, where tests confirmed type A flu, of which H1N1, or swine flu, is one strain.

“Over that weekend I received a few calls about additional children, and by the following Monday we had seven. Then we rapidly progressed to where we have had somewhere in the neighborhood of 100 students out every day,” he said.

“Last Friday we had 140 kids out.”

Since then, he said, an average of about 100 children per day had either not shown up for class, or had been sent home when they showed flu-like symptoms.

That is not to say all have swine flu. Medical authorities no longer generally test specifically for the H1N1 strain, and most people with symptoms do not even seek medical attention. Some of the absent students could have other illness, some might be kept home by their parents out of concern about swine flu, some kids might simply use the outbreak as an excuse, and some had other reasons to miss a day. But by his calculation, 30 or 40 of the daily absences were for multiple days, and likely due to flu.

On the worst day for absences, Mr. Nixon noted, it was a half day for parent-teacher conferences, the day before Halloween, it was a Friday and there were no sports.

“Under those circumstances, even without the flu, you would assume your absence rate would be a little higher than usual,” he said.

The rash of illness has affected all areas of school life, particularly sports, probably because of the close physical contact.

“The flu has affected every sport at every level at one time or another. Whenever in our sports groups, 20 per cent began to show flu-like symptoms, that’s when we shut it down. At one point or other, all sports were shut down,” Mr. Nixon said.

High levels of illness were one reason for stopping sporting events; another was that other off-Island schools were reluctant to play Island teams.

Other activities, anything involving a gathering of more than normal class size, continue to be shut down, although Mr. Nixon stressed they were being postponed, not cancelled.

“Yesterday [Wedenesday] I postponed the fall play,” he said.

One reason was concern about spreading illness, another was budgetary.

“There were purchases and licenses that had to be arranged weeks in advance. With a limited budget we didn’t want to invest in advertising and tickets and all these things we could lose if things got worse.

“We’ve also stopped the peer leadership group, which is 40 to 60 students, run through the guidance department. And we postponed the National Honor Society induction ceremony.

“We can’t predict that two weeks from now we’ll be fine. We could be worse. It could be the same. It’s hard to say. I’ve had to make a decision on future events, based on the information I have today.”

The principal said he had not considered closing the school for a number of reasons. First, he said:

“Even if you have 100 children out sick, there are still another 600 who are healthy and whose other needs must be met.”

Second, he believed school was “a more controlled environment [where] we have adults monitoring things, sending kids to the nurse who can tell the parents to keep the kid home if need be.”

And third, so far almost none of the school’s 125 staff had been affected by flu. The only schools in the state which had been forced to close were those where so many teachers were off sick that children could not be adequately instructed and supervised.

The advice from state authorities also was that schools need not close unless the flu significantly affected the faculty.

Mr. Nixon said the school’s response to the outbreak had won praise from the state Department of Public Health, making it something of a model.

To date, though there have been many cases, there have been no serious ones.

“I think it is a testament to our staff, students and parents that people haven’t blown it out of proportion and panicked, and understand the constraints we’re under,” Mr. Nixon said.

One thing neither he nor Vineyard schools superintendent Dr. James H. Weiss could explain, however, was why the high school had been so affected.

None of the Island elementary schools have so far reported any significant infection problems. Mr. Weiss said the Oak Bluffs school had reported six possible cases, and the others only one or two each.

“Perhaps the high school kids have closer social contact; we just don’t know,” he said.

Another mystery is where the vaccines are.

Ron MacLaren, the spokesman for the Martha’s Vineyard Public Health Coalition, a group comprising the various town health agents and representatives of the hospital, Vineyard Nursing Association, emergency management and the Wampanoag tribe, said there should be more available by now.

“The CDC [Centers for Disease Control, which coordinates the manufacture of the H1N1 vaccine] is reporting over 12 million doses have been produced, and orders for only 10 million. So if they have it, then how come we can’t get it?” he asked.

“The state Department of Public Health keeps sending us updates and saying there’s more vaccine on the way, but they haven’t got all they were supposed to get.

“It seems mostly to be a distribution problem now, not one of supply.”

His concern was that the logistical problems at the state and federal level did not lead to confusion among the public at the local level.

For example, he said: “The clinics at the schools are only for kids enrolled at those schools; other people can’t just show up at the school.”

The shortages made for inevitable complexities. The original plan worked out by the Island Health Coalition — on the assurance that there would be adequate supplies of vaccine for both the swine flu and regular flu — was that there would be one big clinic for the public on Veterans Day.

Now there may be several.

The first of them, next Wednesday at the high school, will run from 8 a.m. to noon, and will only administer vaccine for seasonal flu. People wishing to drive must first go to one of two staging points, at Waban Park in Oak Bluffs, or the Agricultural Hall in West Tisbury. The staging points will open at 7 a.m.

But in a statement outlining procedures for the clinic, the coalition noted it had only 1,200 doses of vaccine to distribute.

“We got a phone call from one of the private distributors a couple of weeks ago, cancelling 500 of our expected doses,” said Sandie Corr-Dolby, RN, clinical director of the Vineyard Nursing Association.

“The state also is having trouble finding what they need. So they could not provide as many as promised. So we are about 1,000 down on what we thought we would have. We thought we’d have about 2,200 doses, and we’ll be going in with about 1,200,” she said.

Organizers hope that will be enough to meet demand Wednesday. If not, there will probably be another clinic, if and when more vaccine becomes available.

Mr. MacLaren said a further public clinic is still under discussion. Meanwhile the focus remains on getting to the highest risk groups first, which in the case of H1N1 is pregnant women, children aged six months to four years and health care workers.

“The second risk group is school-age kids,” Mr. MacLaren said. “That’s what we’re moving on to now. Once that is dealt with, then we’re looking at everyone from 25 to 64, which is a fairly large group. That’s where we anticipate having an all-Island clinic.

“After that group, then we concentrate on those 65 and over.”

Oldest people are considered least at risk for H1N1 due to residual immunity from their early lives.

But the priorities are different with seasonal flu, where older people are at highest risk.

Another worry now is that with flu continuing to spread on the Island, some people who believe they have had the disease will not get inoculated. Which could be a big mistake.

“The most important thing to remember is that even if they have had flu-like symptoms, they should still, if they are well enough, go ahead and get their shot,” said Mr. MacLaren. “Because there is no guarantee that what they had is what they are being vaccinated for.”

Otherwise, the best advice remains this: if you feel sick, stay home. And if your child feels sick, keep her home.