What other mammals can be infected? Dogs? Deer?
Do we need to vax every animal around us ever 6 months to prevent transmission?
We do not have enough trial data to determine how often cats should be injected, but human safety trials are ongoing, and in 5 or 10 years after the results are evaluated we might know more.
in the meantime everyone must get cat masks, especially if they are in an indoor setting where they could be infected by humans.