The smallpox vaccine kills one or two people out of a million. This is not completely safe, and yet it was necessary that all around a smallpox case be vaccinated to eliminate the disease. Hundreds die, so millions can live.
Weinstein is a bit of a scientific joke. Most vaccines are extremely safe. There are vaccines that are a bit less safe, but those are rarely given these days.
Weinstein is one of the most honest and brightest out there, and past performance does not well inform of of likely future performance as the global world order collapses, as our leaders clearly do their jobs less well than their ancestors did.