BSG groaner

Battlestar Galactica, season 2 episode 7:

"We know it as lymphocytic encephalitis. The disease is carried by rodents - rats, mostly - but a couple hundred years ago humans developed an immunity. Now, I can create a simple vaccine that will dramatically reverse the effect of the virus on the Cylons. But they have an antibody in their blood that breaks down the RNA of the vaccine. So they will need regular, close-interval, injections of the vaccine, or they will die."
- Dr Cottle on the Cylon-killing virus (similar to LCMV in real life)

*groannnnnnn*

OK so presumably since the vaccine has RNA, it's some kind of live attenuated or replication-deficient version of the Cylon virus. So if the Cylons can form Abs that can target ("break down"???) the viral vaccine RNA, why the hell aren't they immune to the wild-type isolate from the Earth beacon then?

Also, if a vaccine is chewed up by the immune system before it can mount an effective response against the target antigen, it's a pretty frakking useless vaccine and I don't see how it could possibly "reverse the effects" of the virus.

(in real life anti-RNA antibodies are found in patients with autoimmune diseases like lupus and multiple sclerosis, and synthetic anti-RNA Abs are being made for various purposes. I don't know if you get anti-viral-RNA Abs in nature.)