Prevention and control of Avian Infectious Bronchitis Virus

Content available at:
Español (Spanish)
Avian Infectious Bronchitis virus (IBV) is a highly contagious coronavirus that affects the upper respiratory tract of birds.
It is an RNA virus that, by nature, can change rapidly when it replicates within the host.
There are many types of IBV (and variants of those types) with little or no ability to cross-react. Therefore, developing a vaccine against only one type of virus is unlikely to provide adequate protection against another type.
Initially, tests based on neutralizing antibodies were used for IBV typing, but currently the IBV type is genetically identified from the sequence of the viral spike (glycoprotein).
The genetic type of the virus circulating in the field can provide information to select one or more commercial vaccines available for its prevention and control.
This implies that using a vaccine homologous to the circulating virus is the best strategy to guarantee success.
In the absence of a homologous vaccine, the combination of several IBV vaccine types can sometimes provide acceptable protection and meet the goal of reducing field virus replication to prevent or minimize its transmission.
Numerous studies have been conducted to examine different combinations of IBV vaccine types against virus variants and this information can be extremely valuable in developing a vaccine strategy. However, it is currently impossible to predict which combination of vaccine types will provide an acceptable level of protection against new circulating variants of the virus in the field.
The only way to know for sure whether a combination of vaccines will provide adequate protection is to conduct challenge studies in chickens.
INTRODUCTION
Avian Infectious Bronchitis is a worldwide infectious disease of the upper respiratory system that affects chickens.
It is a very important disease from an economic point of view, causing millions of dollars in annual losses to the poultry industry due to production reductions, seizures during processing and mortality.
It also causes losses in breeders and layers due to infections with strains of the virus that cause kidney damage, diarrhea and dehydration.
The pathogen causing the disease is Avian Infectious Bronchitis Virus (IBV), an enveloped RNA virus. Currently, the best and only strategy to control this virus is the use of live attenuated and inactivated vaccines.
Typically, live vaccines are administered to day-old chicks in the hatchery and sometimes in the field at 14-1...