Quebec public health authorities say there will be a second wave of swine flu this fall and winter.

They just don't know when.

Meanwhile they will follow national guidelines on who should get priority when the vaccine is delivered.

That mass vaccination program will have two phases, with the first stage targeting pregnant women, children between six months and five-years-old, all healthcare workers, people in remote communities, and people with chronic illnesses who are under 65 years old.

People who belong to families with a newborn baby or someone with a suppressed immune system will also have priority for the vaccine.

The second phase will include children between five and 18 years old, first responders, and other adults.

Vaccination will take one month

According to public health director Alain Poirier, the mass vaccination campaign will be conducted at more than 100 sites.

"It's around 200 thousand a day, so seven days a week, at the end of 30 days we can reach the whole population that wants the vaccine," said Poirier.

The vaccine that is being produced seems to be effective with just one dose, and safe.

However more doses will eventually be ready in case everyone needs a second vaccination.

Health officials believe that people older than 65 probably have some immunity to swine flu because it resembles a virus that swept the country in 1957.

In the meantime, offcials are still asking everyone to be vigilant about basic hygiene: coughing into the crook of the elbow and frequent hand-washing.