The second wave of H1N1 is well underway in Manitoba, say health officials. (CBC)

The number of people with flu-like illnesses in Manitoba increased in the last week confirming the second wave of the H1N1 flu is well underway, provincial health officials said Thursday.

The province is reporting 24 additional lab-confirmed cases of swine flu, bringing the total to 66 in Manitoba.

The majority of those cases are mild, said Dr. Joel Kettner, Manitoba's chief medical officer of health.

However, health officials were cautious in saying the numbers do not come close to indicating how many people have been infected by the H1N1 virus. Many people have not been diagnosed because they don't bother to go to the hospital when they have mild symptoms.

"We can't imply that this number is anywhere near an estimate of the number of Manitobans who have gotten H1N1 since the beginning of October. It's just the tip of the iceberg," said Kettner. "It's just a portion of people that go in and then the doctor does a test."

Officials would not say where the people with the confirmed cases live in the province. The provincial government's protocol since the spring outbreak of H1N1, or swine flu, has been to not reveal which communities have confirmed cases, for fear it will stigmatize them.

Health officials also released numbers on people treated in hospital intensive-care units for severe respiratory illnesses.

There are 14 patients in ICU, of which 10 are on ventilators to help them breathe. Since early October, 20 people in Manitoba have required intensive care for severe respiratory illness but only one of those has been confirmed to have H1N1, officials said.

Of the 20 people, four were under the age of 18 and nine were from First Nations communities. One of the 20 was pregnant, one was under six years of age and one was a child over six.

Kettner said health officials are trying to determine how many of those in hospital might have received the H1N1 vaccine before they got sick. It can take up to two weeks before the body develops an immunity to H1N1 after receiving the shot, he said, noting that people vaccinated last week aren't protected immediately.

Vaccination clinics still going

At the end of Wednesday, nearly 160,000 shots had been given to Manitobans, according to provincial health officials.

In Winnipeg, as of Thursday evening, 92,163 individuals have been vaccinated since the campaign started Oct. 26, according to the Winnipeg Regional Health Authority.

Wait times at the city's 12 clinics have been negligible in the past two days, said WRHA spokeswoman Heidi Graham.

The clinics are open Thursday until 8 p.m. and will be open Friday from 9:30 a.m. until 4 p.m. Only individuals who fall into one of the following priority categories will be permitted to receive the vaccination:

• Children aged six months to five years.
• Anyone of aboriginal ancestry (First Nations, Métis or Inuit).
• Disadvantaged individuals (for example, the homeless).
• People living in remote or isolated areas.
• People under 65 with a chronic medical condition or other risks, such as severe obesity, drug abuse or alcoholism.
• Anyone with a weakened immune system or those who live with or care for such people.
• Those who live with, or care for, infants younger than six months old.
• Single parents or anyone solely responsible for a dependant.
• Health-care workers and medical first-responders.
• Pregnant women.

H1N1 vaccination clinics in Winnipeg: