We are formally done calling them "vaccines"

Can these experimental shots really be called "vaccines" if they don't stop infection or transmission but simply lessen the severity of symptoms?

No.

Actual vaccines mimic natural immunity through a variety of mechanisms, and they completely prevent infection (except perhaps in the most immunocompromised of patients).

What mRNA therapies do is more accurately described as preemptive anti-virals, based on novel gene editing technology.  It is a therapeutic intervention, not a preventative one.  They cause the body to create the very thing that damages it when COVID strikes — the spike protein — in an attempt to generate an immune response that is neither long-lasting nor leakproof (as it is the case with actual vaccines).  These products don't give you immunity at all — they only give you a dwindling level of protection — you can still get sick, you can still transmit it, you can still die from the disease they supposedly "vaccinate you" against.

Pfizer et al should never have been allowed to label their drugs "vaccines".  What they have done to you and me, in mislabeling their products, is a blatant act of deliberate deceit for profit — they have leveraged public trust in actual vaccines to con people into accepting their shoddy experimental goods under false pretenses.