Getting new drugs approved in Canada can be a lengthy process. But in the case of swine flu vaccine, it took less than six months from the time the virus was identified until millions of doses of the vaccine — Arepranix H1N1 — were shipped across the country.

The federal government gave the green light to the vaccine on Oct. 13, 2009 — on an interim basis — based on limited clinical testing in humans. Final approval came on Oct. 21, 2009 — and clinics began operating within days.

Approval was granted on the condition that GlaxoSmithKline agree to post-market commitments. These include sharing the results of ongoing clinical trials and close monitoring of how the vaccine is working.

The World Health Organization says millions of doses of the vaccine have been administered and there have been very few reports of side effects.

The following is a timeline of the events leading to the rollout of the vaccine.