Addison Gilbert and other hospitals with the Northeast Health System company have revised their visitation policies, and Manchester Essex school officials are planning for vaccination clinics as area institutions continue stepping up their response to growing concern over the spread of the H1N1 — or swine flu — virus.

Northeast, the parent company of Addison Gilbert, Beverly Hospital and BayRidge Hospital in Lynn, has announced that, effective immediately, anyone younger than 18 is prohibited from visiting patients in several areas of Beverly Hospital, including the North Shore Birth Center, Beverly Hospital Labor and Delivery, Beverly Hospital Maternity and Newborn Nursery, Beverly Hospital Special Care Nursery, and Beverly Hospital Inpatient Pediatric Beds on Johnson Floor 5.

Northeast officials also noted that anyone of any age visiting Addison Gilbert, Beverly, or any of its facilities should "refrain" from doing so if they have a runny nose, a cough or any other potential flu symptoms.

"We appreciate the importance of families and visitors to our patients along with their important role in the healing process and understand the hardship that this restriction poses," said registered nurse Theresa D. Sievers, the associate vice president for performance improvement for Beverly, Addison Gilbert and BayRidge hospitals. "However, patient safety is a high priority and these precautions are being put in place with the best interest of our patients in mind as we face this unusual flu season."

Meanwhile, a letter sent home to parents by Manchester Essex School Superintendent Marcia O'Neil, the schools' medical staff and town health officials is asking parents to return a "vaccine consent form" to the schools by tomorrow.

The school district, in conjunction with the Manchester and Essex Boards of Health, "is in the preliminary stages of planning H1N1 influenza vaccination clinics," the letter reads.

"Once permission forms are returned and the H1N1 vaccine arrives, we will notify you of the clinic dates that correspond to your child's age," the letter advises parents. "Clinics will begin with the youngest children first, and subsequent clinics will be scheduled as the vaccine supply is replenished."

The letter also advises parents to take basic steps to try to stop any potential spread of the swine flu — which has, across the nation, primarily affected people younger than 25.

"To protect the health of students," the letter reads, "it is imperative that you do not send children to school if they are sick. By sending sick children to school, you put other children and staff of risk of getting infected."

All of these moves come amid a growing influx of potential swine flu cases — a trend pediatricians are seeing across the region.

When Dr. James Higgins arrived at his office at Pediatric Associates of Greater Salem last week, he had more than 60 voice mails, illustrating the spread of the virus, as well as a growing concern among parents.

"A lot of kids have this," said Dr. Edward Bailey, chairman of pediatrics at North Shore Children's Hospital in Salem, "but what we're finding is that it's no different — other than the numbers — in terms of the severity of the flu virus we see every year."

"We are seeing many, many cases, but most of them are not serious," said Higgins, whose pediatric practice has more than a dozen doctors and 24,000 patients. "The two kids I know of personally who have been hospitalized have underlying health issues," he said. "If anything, most of the kids are less sick than with the average seasonal flu."

In Gloucester, the Cape Ann Emergency Planning Team, in conjunction with the Gloucester Health Department and in partnership with Cape Ann Pediatrics, has held two H1N1 vaccine clinics, the first at Addison Gilbert Hospital more than two weeks ago, and the second last Thursday at Fuller School, and more are expected to be announced through the city Health Department's Web site. But the vaccinations have been geared to pregnant women and children ages 6 months to 9 years.

The city's Health Department is also working on a schedule to send to parents for when the vaccine becomes available to administer to Gloucester schoolchildren.

At Pediatric Associates of Greater Salem, Higgins estimated the practice has inoculated between 700 and 800 children, out of some 5,000 in the practice who fall into the high-risk tier.

"The threat has been oversold," Higgins said, "and the treatment has been oversold because they have not been able to deliver the amount of vaccination they said they were going to. And that's what makes people crazy."

Bailey said he is aware of no North Shore swine flu deaths. He advised people to get the seasonal flu vaccine.

"Soon we're going to have the arrival of seasonal flu, and it may be mixing in with this," Bailey said. "Just because you have one of these flus doesn't mean you can't get the other."

Swine flu vaccine supply is expected to improve over the next month or so, according to the American Academy of Pediatrics, which recommends vaccinating young people between the ages of 6 months and 24 years, as well as people with chronic medical conditions who are at an increased risk of complications from influenza.

"Realize that most children are going to be well," Higgins said. "Most are going to be sick and get better before they are going to be immunized."

Staff writers Jonathan L'Ecuyer, Paul Leighton and Amanda McGregor contributed to this report.