That is a good question. Some companies make unique vaccines, but others produce vaccines that are somewhat similar. Canada has a bulk purchasing system for vaccines. Public Works and Government Services Canada is responsible for procuring vaccines and it uses a tendering process for that purpose.
The competitive system in Canada is far from perfect. That is another debate. I can come back to that. That said, the system ensures that vaccine prices in Canada are much lower compared with those in the rest of the world.