Dancing David
Penultimate Amazing
It is not at all unusual for a few people to die of any vaccine.
Some people are allergic to the medium a vaccine is grown in, for one thing.
Sometimes the vaccine itself is dangerous.
The polio vaccine kills people. And not always the people it is protecting! It is a live vaccine, and when an older person who either never was vaccinated or whose immunity has faded changes the diapers they can contract it.
And sometimes the batch is contaminated or old or counterfeit.
Do they still use live polio vaccine? The risks are low they are not what you would call usual. Now albumin allergy would be a real problem, but anaphlactic shock would be detectable,