Nope...it does not..
When a PHYSICIAN, NURSE, TECHNICIAN, or Medical Doctor apply inactivated (dead), attenuated or fragmented viruses in anybodies body, we are boosting the production of specific proteins called inmunoglobulins, that will reject or neutralize that particular virus....
Thats what we call antigenicity (the capability of the body, to produce defenses, or antibodies against that specific virus)
Nowadays, very rarely, attenuated viruses are used, but rather the small fragmented version of the virus particles (such as it happens in vacines against human papiloma viruses)....
Those vaccines doesnt make anything stronger nor weaker....it just gives to the person (or animal for that particular case), receiving it, the capability to manufacture Immunoglobuline proteins of the "M" or macro type, or the "g" permanent type..
It does not make the virus any weaker, or stronger (it has nothing to do with that) it only neutralizes such virus.....avoiding the disease before the virus spreads inside of the body,,,,(that is the aim of such vaccines, most of them protect the body for a lifetime)...however, the virus itself, does not become stronger nor weaker.....nothing to do with that,,,,,