Avian infectious bronchitis (IB)

Avishield IB GI-13 and its effect on egg production during the laying period

The avian infectious bronchitis virus (IBV) can replicate in the oviduct and cause permanent damage in young hens producing the false layer syndrome.

Symptoms of laying hens with infectious bronchitus virus

  • Serious drop in egg production
  • Detrimental effects on egg quality
  • Reduced the hatchability of breeding eggs.


In areas with high pressure of circulating field viruses, live attenuated IB vaccines are also used during the laying period with the intention of keeping the local protection of the respiratory tract at a high level. 1

The Vaccine

The vaccine strain IB V-173/11 contained in the Avishield IB GI-13 vaccine is a strain that genetically belongs to the GI-13 lineage and antigenically to the 793B IBV serotype.

Viral infections with this serotype occur frequently in Europe. Therefore most vaccination programs in broilers, layers and breeders include live vaccines of this type 2.

Avishield IB GI-13, is part of the poultry vaccine range against multiple poultry diseases – find out more about our solutions.

Summary of study design:

One group of layer-type hens at the peak of lay was vaccinated by spray method with a 10-fold maximum dose and 4 weeks later with a maximum dose of Avishield IB GI-13. Non-vaccinated layer chickens were included as a control group.

Throughout the study observation period, the laying hens were clinically monitored and eggs were collected to assess quantity and eggshell quality.

The egg production per chicken at different points of the observation period is shown in the graphic. 


Observations between the vaccinated chickens and control group 2:

  • No clinical signs of IB-related disease
  • The egg quality was not altered
  • No statistical significant difference in egg production 


  1. J. J. (Sjaak) de Wit , Jane K. A. Cook & Harold M. J. F. van der Heijden (2011): “Infectious bronchitis virus variants: a review of the history, current situation and control measures”, Avian Pathology, 40:3, 223-235, DOI: 10.1080/03079457.2011.566260

  2. M. G. Dragović et al.(2022): “Safety of the live attenuated vaccine Avishield IB GI-13 against infectious bronchitis in SPF chickens during laying period”, Proceedings XIV symposium Poultry days, Croatia, May 11‐14, 2022, pp. 71-77