How Vaccines Helped All But Eradicate Vaccine-Preventable Diseases in the U.S.

Sorry to hear about your sister.

If nothing is to be done if, for example, "only" 999 of out of a 1000 people are helped, then nothing would ever be done and we would be living in the Dark Ages still. It is sad that, for example, 1 out of a 1000 may have a bad reaction, especially if one is personally affected, but we live in a fallen sinful earth and nothing on this present earth will be perfect after Adam sinned; perfection will be in the new heavens and earth.