Suicide is defined by intent. If you kill yourself by accident (reckless driving, extreme sports, accidental overdose, etc.), life insurance would likely pay out to your beneficiaries. If there is evidence you killed yourself on purpose (close range gunshot wound, hanging, leaving a note, etc.), insurance probably would not pay out under a suicide clause. Anti-Vaxers are not intending to kill themselves. It is reckless behavior that may result in death, but that is not their intended outcome — so, no. (All this courtesy of my law school graduate wife)