The present invention relates to infectious bronchitis (IB) viruses derived from a recently identified genotype of IB virus known as IB-QX, or from viruses that are genetically related to IB-QX, herein referred to as IB-QX-like viruses. The IB viruses of the invention may be live and attenuated or inactivated. Live, attenuated IB viruses of the invention may be produced by serial passaging of an IB-QX-like virus. The IB viruses of the invention are useful for, inter alia, vaccines against IB-QX and IB-QX-like viruses. Heretofore, known vaccine strains of IB viruses have proven insufficient to protect against infectious bronchitis caused by IB-QX and IB-QX-like viruses.
