From 1850 onwards French cultivators were compelled, in order to keep up their silk supply, to import graine from uninfected districts.
There is a FeLV vaccine that can be given to uninfected cats.
If a person with a cold touches his runny nose or watery eyes, then shakes hands with another person, some of the virus is transferred to the uninfected person.
No contact with uninfected people should occur for at least 24 hours after the fever is gone, and a minimum of 72 hours is recommended for safety.
If you have one infected nail, don't use the same grooming products (such as clippers or files) on uninfected nails.