100% effective vaccines don't exist. Merriam Webster's old definition excluded many vaccines ordinary people called vaccines. Diphtheria and tetanus most clear

100% effective vaccines don't exist. Merriam Webster's old definition excluded many vaccines ordinary people called vaccines. Diphtheria and tetanus most clearly. And other dictionaries had definitions compatible with mRNA vaccines.[1] [1] https://en.wiktionary.org/w/index.php?title=vaccine&oldid=51346997 https://en.wiktionary.org/w/index.php?title=vaccine&oldid=51...