Far be it from me to doubt a stranger on the Internet, but can you point out any medical textbook or dictionary written pre-2020 that limits the definition of "vaccine" to "attenuated viruses"?
2021-01-18: https://web.archive.org/web/20210118193104/https://www.merri...
2021-01-26: https://web.archive.org/web/20210126065143/https://www.merri...