For months, Taiwan has been unable to purchase doses of the BioNTech coronavirus vaccine, and the island’s leaders blame “Chinese intervention.” China, which regards Taiwan as its own territory, calls this accusation “fabricated out of nothing.” It is unclear what steps, if any, the government in Beijing has taken to disrupt Taiwan’s dealings with BioNTech, the German drugmaker that developed the vaccine with Pfizer. BioNTech declined to comment. But the crux of the problem is that a Chinese company claims the exclusive commercial rights to distribute BioNTech’s vaccine in Taiwan. And for many people in the self-governing democracy, buying shots from a mainland Chinese business is simply unpalatable.