
"In the past, cross-protection between different
strains of PRRS has been sporadic and unpredictable.
Protection when re-exposed to the same homogeneous
virus is more predictable.
I
did a series of trials involving pregnant sows,
and the results demonstrated partial to full protection
when challenged with a wild type PRRS virus. These
sows had a history of prior field PRRS virus exposure
and multiple doses of killed MJPRRS® vaccine.
The challenge PRRS viruses were at least 8% different
from what the sows were exposed to previously. Additionally,
each challenge virus used had previously been associated
with severe clinical disease in non-related herds.
Preliminary
data is positive regarding this new MJPRRS®
vaccine. Additional trials are planned to confirm
these findings. For a more complete summary of these
trial results, refer to poster/abstract entitled
“Protection against heterologous PRRSV challenge
in pregnant sows immunized with multivalent PRRS
vaccine 1.”
Mark
Wagner, D.V.M.
Fairmont Vet Clinic
Fairmont, Minnesota
1.
Wagner M., et al. Protection against heterologous
PRRSV challenge in pregnant sows immunized with
multivalent PRRSV vaccines. In: International PRRS
Symposium, 2005 Dec. 2-3; St. Louis, MO.