In terms of Kalina ' lifestyle no she may not getting vaccines and what not but you forget that in some ways Miz is ahead even in terms of " our world" (healing Gnosis, and godly intervention for example) and her life may be cut shorter due to it. How ever that isn't actual "lifespan" rather than outside forces.
Kalina could live to 20 years as easily as a human. But outside forces would affect her lifespan. However in actual terms of aging she of course won't age faster. So really it does all come down to the fact a kelvic could very well live a "human" like life in a city. They are simply not just animals that turn human that require special medicine. In fact the lore states exactly that. Most medicine Miz does have the same effect on them as humans.
It really does just come down to life style to lifespan.