There's effectively zero chance that the vaccine kills 1% of those vaccinated. They would have caught that in the Phase II, and probably the Phase I since they do also track adverse events short of death.
The risk is e.g. that the vaccine has unforeseen side effects that kill or seriously injure one person in 10^4 or 10^5. That could still be a highly favorable tradeoff for society; but if AstraZeneca gets no credit for the people their vaccine saved and pays out normal rates--potentially billions of dollars--for the people their vaccine injured, then it's a terrible tradeoff for AstraZeneca.
All vaccines present some version of this problem, and that's why the American government takes liability for vaccine injuries. I'd guess that Europe has been able to avoid that (so far) only because their socialized health care reduces the need for injured patients to sue to recover their medical expenses, and because of their less litigious society in general.
The risk is e.g. that the vaccine has unforeseen side effects that kill or seriously injure one person in 10^4 or 10^5. That could still be a highly favorable tradeoff for society; but if AstraZeneca gets no credit for the people their vaccine saved and pays out normal rates--potentially billions of dollars--for the people their vaccine injured, then it's a terrible tradeoff for AstraZeneca.
All vaccines present some version of this problem, and that's why the American government takes liability for vaccine injuries. I'd guess that Europe has been able to avoid that (so far) only because their socialized health care reduces the need for injured patients to sue to recover their medical expenses, and because of their less litigious society in general.