As to why it's refused, you'd have to ask the people in government who are in charge of that kind of decision-making.
If you look at the history of Canada, the Canadian government has had to make a choice between supporting improved access to medications in low- and middle-income countries versus supporting intellectual property rights, and we go back to 1999. There have been about six or seven times when they've had to make that choice, and every time they've made the choice of supporting intellectual property rights as opposed to better access to medications in the poorer countries.