Mass immunization clinics set up across Newfoundland and Labrador to inoculate people against the H1N1 virus were to resume Thursday, with nurses saying the work of administering the vaccine and caring for the sick is taking a physical and mental toll.

After a 24-hour break for Remembrance Day, clinics were to reopen, and the priority groups of people who can get the swine flu shot have been expanded to those under 65 who have chronic respiratory diseases.

The president of the Newfoundland and Labrador Nurses Union, Debbie Forward, told CBC News this week that nurses are feeling the impact of the H1N1 outbreak.

Nurses who are giving the shots to people are working long hours to keep up with the immunization schedule, Forward said. It's also physically exhausting for the nurses who deal directly with swine flu patients, she said.

"For patients with influenza, and for H1N1, nurses have to wear personal protective equipment to make sure they don't become infected with the virus themselves," Forward said, "so this means every time they come in contact with a patient, they have to don a gown and gloves and a mask and a face shield, and wear all this equipment while caring for someone who is very, very ill."

Forward said the work is also mentally draining for nurses and other front-line medical workers caring for people who are fighting the virus.

"They're working in the middle of this disease — whether you're working in an ICU, or in the middle of a flu-assessment clinic, or a unit [where] we have a patient — and you're concerned that you're [in] such close contact, that you might get it yourself. You're concerned about bringing it home to your family."

Nurses who work at the hospital in Grand Falls-Windsor are finding it most hard, Forward said.

"They've had three deaths at that facility," Forward said. "I know the nurses who work in ICU, and other nurses in that hospital who have supported them, have found it really difficult. It's been very, very busy."

Forward said hospital administrators have been telling nurses that they won't be allowed to take any kind of leave, annual or personal, for the time being.

Health Minister Jerome Kennedy said about 20 per cent of the province's population has now received the vaccine, a rate he said is one of the highest across the country.

"Compared to what is happening in other provinces, we are managing to use our vaccine to get out to a larger number of groups and a more diverse section of our population," Kennedy said.

Health officials expect that elementary school students will start getting the flu shot on Monday.