S1 gene characteristics and efficacy of vaccination against infectious bronchitis virus field isolates from the United States and Israel (1996 to 2000)

Abstract

The S1 genes of isolates of avian coronavirus infectious bronchitis virus (IBV) from commercial chickens in the US and Israel (20 isolates from each country) were studied using reverse transcription-polymerase chain reaction restriction fragment length polymorphism and sequencing. Partial sequences spanning the amino terminus region of S1 from amino acid residues 48 to 219, based on the Beaudette strain, were used for analysis. Phylogenetic clustering and high-sequence identity values were used to identify isolates that appeared to be derived from live IBV vaccines used in the two countries. Novel variant strains, unrelated by S1 sequencing and restriction fragment length polymorphism analyses to reference and vaccine strains, were also identified. Based on S1 sequence identity to available vaccines, the potential to use vaccination to control IBV infections was evaluated. Vaccination with commercial live strains Massachusetts (Mass), Arkansas (Ark) or DE/072/92, generally produced immunity against vaccine-related field isolates displaying high S1 sequence similarities (]/90%) to the respective vaccine strains. Immunization with a bivalent vaccine containing the Mass and Ark strains provided good cross-protection, averaging 81% against challenge with five variant isolates from the US having amino acid identity values ranging from 62 to 69% to Mass and from 68 to 83% to Ark, respectively. In contrast, the H120 vaccine strain induced low levels of protection, ranging from 25 to 58% against variant field isolates from Israel with amino acid identity values from 65 to 67%.

Infectious bronchitis virus S1 gene sequence comparison is a better predictor of challenge of immunity in chickens than serotyping by virus neutralization

“…Extraction of IBV RNA, reverse transcriptase-polymerase chain reaction of S1 gene fragments and analysis of sequences were performed as described elsewhere (Gelb et al ., 2005).…”

Phylogeny and S1 Gene Variation of Infectious Bronchitis Virus Detected in Broilers and Layers in Turkey

“…However, different strains of IBV have been circulating in the Middle East. For example, IBV variants like Q1 (CK/CH/LDL97I/97) (1,11,14,17,20,26,27), IBV variant-1 (793/B, IS/222/96, IS/251/ 96, and IS/64714/96), IBV variant-2 (IS/223/96, IS/572/98, IS/ 585/98, and IS/589/98), Egypt/Beni-Seuf/01, Sul/01/09, D274, and IS/885/00 as well as vaccine strains derived from Massachusetts and 4/91, (8,18,19,24,25) have been detected.…”

Serological Studies of Infectious Bronchitis Vaccines against Japanese Field Isolates of Homologous and Heterologous Genotypes

“…Liu et al [15] and Gelb et al [7] reported the relationship between genotype and efficacy of a vaccine against field isolates and showed that vaccines with high S1 identity values are protective against field isolates.…”

“…In spite of the use of vaccines for control of IB, the disease continues to be a problem in commercial poultry because IBV readily undergoes mutation in chickens and some serotypes do not cross-protect against antigenically unrelated serotypes, including new variant serotypes [7,12].…”