This is interesting, but is also consistent with literatures I have read about this virus in the past - it says something like, over 75% of cats are exposed to FeLV virus, and the majority of them simply do not get infected due to the natural resistance they have built into already (unless their immune system is already very compromised) - of course, kittens will be a little bit more susceptible due to their premature immune system..but still this is encouraging..
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Nina Sent: Wednesday, September 07, 2005 1:17 PM To: [email protected] Subject: Adult cat resistance to Felv Hello Everyone, I've been discussing resistance ratios of healthy adult cats to Felv with the vet that monitors my IBD list. She just sent this to me this morning and knew you guys would be interested. Nina Lisa...this is a question that comes up quite frequently. The natural resistance to FeLV infection in cats older than 4 to 6 months is very well established among feline retrovirologist. While susceptibility to FIV remains constant throughout life, that simply is not the case with FeLV. While it is NOT impossible to infect an adult cat, the inoculate of FeLV has to be really significant (or repeated) in order to infect. This has been shown in virtually all FeLV vaccine Challenge studies involving adult cats. It is MOST difficult to assess efficacy of an FeLV vaccine when using adults as controls...because they just don't get infected. Schering Plough has turned this into a "3-year guarantee" for their FeLV vaccine (a VERY reactive adjuvanted vaccine). This is a 'no-brainer'...obviously! Fact is, ALL FeLV vaccines look good in the long run because of this natural resistance. This phenomenon is apparently related to T-cell maturity in the individual cat and the interaction of those lymphocytes with specific epitopes of FeLV. The updated Feline Vaccination Guidelines are being written now. This material will be included to more clearly point out this phenomenon. I do have a copy of the original paper...it goes back a number of years now and was published in a virology journal...Richard Olsen (who developed the first FeLV vaccine for Norden Laboratories) and Jennifer Royjko (sp?) published the manuscript. I don't have that paper with me...but will try to dig this out and send the ref if you're really interested in getting into that. RBFord
