Albertans over age 75 are eligible to receive the H1N1 vaccine today, health officials announced yesterday.

Vaccines will further be available to those 65 and older on Thursday.

Though seniors have a greater natural immunity to the virus, the vaccine is offered to them first, as they’re at greatest risk if they do contract H1N1, Alberta’s senior medical officer of health Dr. Andre Corriveau said yesterday.

Though officials wouldn’t comment on when the vaccine will be eligible to everyone, they said they’ll expand the eligibility list as supply dictates.

Over half-a-million Albertans have been vaccinated so far.

“We will strive to immunize all the people we can before Christmas, all people who want to be immunized, because this is the best way to prevent a third wave of H1N1, or at least minimize its impact during our long winter,” Corriveau said.

These latest groups are in addition to those currently identified as priority: Chronically ill people between ages five and 64; pregnant women; and children between six months and five years old.

Caregivers and parents of babies and emergency services workers have also been identified as a priority.