Avibacterium paragallinarum serovar A, B and C are widespread in various countries, including Indonesia, Malaysia, Vietnam, People’s Republic of China (PRC), Pakistan, Iran and Egypt. Based on Research & Development Medion analysis using the polymerase chain reaction (PCR) method on Coryza isolates for the last 5 years, serovar A, B, C1 and C4 were found circulating in Indonesia. The dominance of 49% of the isolates was identified as C4 serovar with distribution in almost all regions in Indonesia (Graph 1). It was reported on GenBank that serovar C4 was also found in Iran.
The results of the cross-protection test against 9 Avibacterium paragallinarum serovar based on the Kume Scheme showed that there was only partial cross-protection between serovars. Serovar C4 provides the best protection for homologous serovar only. It is important to select a vaccine that is homologous to the circulating serovar.