Antivax doublespeak
Conspiracy koo koo says:
"By definition, not a “vaccine” as it clearly does NOT “provide immunity”.
vac·cine
/vakˈsēn/
noun
a substance used to stimulate the production of antibodies and provide immunity against one or several diseases, prepared from the causative agent of a disease, its products, or a synthetic substitute, treated to act as an antigen without inducing the disease."
Like, huh? Hairsplitting? Gaslighting?
= new reply since forum marked as read
I'd say the vaccines are a form of prophylaxis--a specific form that aims to produce an immune response. That immune response may not confer 100% "immunity" (meaning of "immunity" could also be disputed or more specifically quantified), but it was still an induced immune response and thus "vaccine" is the best word to describe these products.
Some gqp call them "gene therapy", but "therapy" should be used to describe treatment on a condition a patient is known to have. That is, you don't have "preventative therapy".
The semantic common ground you might be able to find with this person is:
"mRNA/adenovirus vaccine with X% efficacy" -- where the "X%" you've likely agreed to disagree. 
Questions for them: What would you call these products if not "vaccines"? Are flu vaccines, with their lower efficacy, also not vaccines? Are vaccines in testing that had low efficacy or yielded bad side effects no longer "vaccines'? Does the word "vaccine" describe the method and intent of a product or its results? If a vaccine exists that confers immunity, but the target virus evolves to transcend that immunity, is the vaccine no longer a vaccine, or rather is it a vaccine that is simply no longer effective? etc. etc. etc.
