Quebec's chief public health officer, Dr. Alain Poirier, says children need only one half-dose of the vaccine. (CBC)

Quebec’s chief public health officer says children require only a single half-dose of the H1N1 vaccine.

Health Canada’s recommendation so far has been that children from six months to nine years of age should receive the adjuvanted vaccine in two half-doses, 21 days apart.

However, Dr. Alain Poirier said Quebec’s testing has indicated that one half-dose produces sufficient antibodies to protect children against swine flu.

In an interview with CBC Radio’s Homerun, Poirier said researchers in Quebec have tested 150 vaccinated children.

"One hundred per cent of them had the right level of antibodies," said Poirier.

But some parents say the practice on the ground doesn’t necessarily seem to be reflecting that recommendation.

Kathleen Michetti said she was surprised at how smoothly the process was to get her two daughters vaccinated against the flu on Montreal’s South Shore.

"Until I spoke to my brother, who went to another centre, and who was told his kids had to go back in three weeks for another dose," said Michetti.

Michetti said she returned to the centre where her children had been vaccinated, and was told they would not need a booster shot.

Poirier said it is possible some nurses are not up to date on the province’s recommendation.

"But these parents who had their children having one shot, as of now, that will be enough," said Poirier.

Unless there is a change in the recommendation, Poirier said clinics that made second appointments for children will call parents to cancel them in the next few weeks.

Infants under six months of age are not being given the vaccine, Poirier said.