HOW PREVALENT ARE EIMERIA MAXIMA VARIANTS IN THE US, AND IS COCCIVAC-B CROSS-PROTECTIVE?
A. Based on a recent survey of 33 isolates of Eimeria maxima collected from 11 states and 18 major poultry integrators throughout the US, only three of the isolates (less than 10%) showed only partial protection by the Coccivac strain of E. maxima. In other words, the prevalence of E. maxima among US poultry integrators that is highly variant to the E. maxima in Coccivac is very low and is not of major significance at this time. The results of the study also indicate that if birds are properly immunized, the vaccine strain of E. maxima in Coccivac-B would protect against a wide range of field isolates encountered in commercial operations in the US. Q.
