RT Journal Article SR Electronic(1) A1 Cavanagh, David A1 Davis, Philip J. A1 Darbyshire, James H. A1 Peters, Richard W.YR 1986 T1 Coronavirus IBV: Virus Retaining Spike Glycopolypeptide S2 but Not S1 Is Unable to Induce Virus-neutralizing or Haemagglutination-inhibiting Antibody, or Induce Chicken Tracheal Protection JF Journal of General Virology, VO 67 IS 7 SP 1435 OP 1442 DO https://doi.org/10.1099/0022-1317-67-7-1435 PB Microbiology Society, SN 1465-2099, AB Summary Avian infectious bronchitis coronavirus (IBV) inactivated by β-propiolactone induce partial protection of the trachea in up to 40% of chickens following one intramuscular inoculation 4 to 6 weeks prior to challenge. Retention of an intact tracheal ciliated epithelium 4 days after challenge was the criterion of protection. There was no correlation between protection and serum titres of virus-neutralizing (VN) and haemagglutination-inhibiting (HI) antibody, which were maximal at about 4 weeks after inoculation. Virus from which the S1 but not the S2 (spike-anchoring) spike glycopolypeptide had been removed by urea did not induce protection or VN or HI antibody. Four intramuscular inoculations of monomeric S1 induced VN and HI antibody in two and four chickens respectively. These results indicate that VN and HI antibodies are induced primarily by S1, that intact spikes are a major requirement for the induction of protective immunity and that this propertyis probably associated with S1., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-67-7-1435