Efficacy of inactivated infectious bursal disease (IBD) vaccines: Comparison of serology with protection of progeny chickens against IBD virus strains of varying virulence

Abstract

The efficacy of inactivated infectious bursal disease vaccines was determined by measuring both the antibody response of vaccinated chickens and clinical protection of progeny chicks from vaccinated dams. Similar virus neutralizing (VN) antibody titres were obtained in 4-week-old chickens and mature hens after vaccination with one vaccine dose. VN titres below 10 log 2 increased considerably between the fourth and seventh week after vaccination in 4-week-old chickens as well as in mature chickens. All 2-week-old progeny chicks with serum VN antibody titres of at least 9 log 2 were clinically protected against the classical virulent 52/70 infectious bursal disease virus (IBDV) strain, as well as against the very virulent IBDV (vvIBDV) strain D6948. However, vaccination often did not prevent subclinical infection in these 2-week-old progeny chicks, which often resulted in severe lymphocyte depletion in the bursa of Fabricius. Even a serum VN titre of 11 log 2 was not always sufficient to prevent severe bursal damage. Although 52/70 IBDV and vvIBDV were equally pathogenic in 2-weekold specific pathogen free chickens, significant higher maternal antibody titres were required to prevent the adverse effects of vvIBDV in comparison with 52/70 IBDV. The relation between the serological response of chickens after application of inactivated IBD vaccines and the protection of progeny chicks of vaccinated dams depended on both the virulence of the IBDV challenge strain and the IBDV strain in the vaccine.

Evaluation of the Protection against Infectious Bursal Disease (IBD) Challenge in Progeny Born to Parents Having Received a Vaccination Program Using a Herpesvirus of Turkey-Infectious Bursal Disease (HVT-IBD) Vector Vaccine

“…IBD leads to bursa lesions and immunodepression [8]. Broiler breeder vaccination against IBD is usually based on the injection of at least one inactivated vaccine in oil adjuvant [9], typically included in a combined vaccine. Priming using one or several live IBD vaccine (s) has been the most common way to immunize the breeders so far, as early protection against IBD is required by vaccination programs of the breeders.…”

Analyses of the results of different test systems in the 2005 global proficiency testing schemes for infectious bursal disease virus and Newcastle disease virus antibody detection in chicken serum

“…When international reference sera are included in these studies, the quantitative results of such sera would provide very useful information on the comparability of the test results of this study to those of other studies. This study shows that when a laboratory reports a correlation between an antibody titre for IBDV or NDV and protection (Thayer et al ., 1987;Van den Berg & Meulemans, 1991;Maas et al ., 2001Maas et al ., , 2003Rahman et al ., 2004), or vaccine efficacy (Maas et al ., 2001(Maas et al ., , 2003Mebatsion et al ., 2002;Claassen et al ., 2004), or breakthrough titres for vaccination, and so on, without including results for any international reference sera, these titres cannot be interpreted correctly by other laboratories or authorities. Without the use of reference sera it is not possible to know the variation between laboratories or the comparability with other laboratories.…”

Determination of breakthrough maternal antibodies titres by two intermediate and two intermediate plus vaccine strains against Gumboro disease, in commercial broilers

“…The results of the present study in experiment A show that the intermediate strains did not breakthrough mean ELISA antibody titres of 6.3 log 2 and 6.4 log 2 and that they are consistent with Van Loon's (2001) study, which reports that intermediate strains did not breakthrough maternal antibody titres higher than 6 log 2 . Furthermore, Lutticken (1994) and Maas (2001) σμός της ηλικίας χορήγησης του εμβολίου, ώστε αυτός να είναι αποτελεσματικός. Από τις αρχές της δεκαετίας του 1990, στην Ευρώπη (Kouwenhoven και Van de Bos 1994), αλλά και στη χώρα μας (Μπουγιουκλής και συν.…”

“…The vaccines' virulence is determined by the histological lesions degree of the bursa of Fabricius. Furthermore, the effectiveness of vaccinations on the progeny also depends on other factors which may be considered as not decisive, one of these being the age at vaccination (Maas et al 2001).…”

“…Titres reach their peak soon after the 23rd week, followed by a decrease at the end of their reproduction period, about the 60th week (Gardin 1991). Active immunization of young progeny with maternal antibodies (Mab) by vaccination, at 1 to 12-days-old of their life, is not effective due to the immaturity of their immune systems (Giamborne et al 1982, Giamborne and Clay 1986, Solano et al 1986) and the interference of maternal antibodies (Kouwenhoven and Van den Boss 1994, Lutticken et al 1994, Maas et al 2001. The effectiveness of vaccinations during the second week of the progeny's life depends on two decisive factors: the interference of the maternal antibodies (Lutticken et al 1994, Maas et al 2001) and the virulence of the vaccines' strains (Haddad et al 1997.…”