Comparative protective immunity provided by live vaccines of Newcastle disease virus or avian metapneumovirus when co-administered alongside classical and variant strains of infectious bronchitis virus in day-old broiler chicks

Abstract

a b s t r a c tThis study reports on the simultaneous administration of live NDV or aMPV subtype B vaccines alongside two live IBV (Massachusetts-H120 and 793B-CR88) vaccines in day-old maternal-antibody positive commercial broiler chicks. In the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live NDV VG/GA-Avinew, live H120 + CR88, or VG/GA-Avinew + H120 + CR88. In the second experiment, live aMPV subtype B vaccine was used in place of NDV. Clinical signs were monitored daily and oropharyngeal swabs were taken at regular intervals for vaccine virus detection. Blood was collected at 21 dpv for serology. 10 chicks from each group were challenged with virulent strains of M41 or QX or aMPV subtype B. For IBV, after 5 days post challenge (dpc), tracheal ciliary protection was assessed. For aMPV, clinical scores were recorded up to 10 dpc. For NDV, haemagglutination inhibition (HI) antibody titres were assayed as an indicator of protective immunity. In both experiments, ciliary protection for IBV vaccinated groups was maintained above 90%. The protection against virulent aMPV challenge was not compromised when aMPV, H120 and CR88 were coadministered. NDV HI mean titres in single and combined NDV-vaccinated groups remained above the protective titre (>3 log 2 ). Both experiments demonstrated that simultaneous administration of live NDV VG/GA-Avinew or aMPV subtype B alongside H120 and CR88 vaccines does not interfere with protection conferred against NDV, IBV or aMPV.

Effect of vaccination program on immune response, production performance, and carcass composition of Ross 308 broiler chickens

“…There were no statistically significant differences in the antibody titer (GMT) throughout the rearing period. Consistent results to those shown in our study were obtained by other authors in similar experiments conducted on specific pathogen-free ( SPF ) birds ( Tarpey et al, 2007 ; Awad et al, 2015 ) and commercial broilers ( CB ) ( Ball et al, 2019 ). Analyzing the ELISA results, it could be concluded that the administration of IB vaccine on d 1 together with aMPV vaccination had no inhibitory effect on the serological response of chickens tested for anti-aMPV antibodies at the end of rearing.…”

“…It should be noted, however, that the level of anti-aMPV maternal antibodies in the examined chicks on d 1 was definitely lower ( P < 0.05) in H1 than in H2 birds. Ball et al (2019) obtained lower values of the mean anti-aMPV antibody titer on d 31 of the life of birds vaccinated on the first day (IB + aMPV) compared to the group of birds vaccinated on the first day only against aMPV. However, the experiment showed that a lower titer of anti-aMPV antibodies in the group vaccinated on the first day against both diseases did not negatively affect immunity to aMPV infection ( Ball et al, 2019 ).…”

Avian Metapneumovirus Infection in Poultry Flocks: A Review of Current Knowledge

“…Despite other reports showing that the produced protection by live vaccines of IBV, NDV, and aMPV did not cooperate when the vaccines were given concurrently in dual or triple mixtures, the humoral immune response to aMPV may be insufficient (Awad et al, 2015). In addition, giving live vaccines containing subtype B of aMPV, NDV, alongside the classical and variant strains of IBV vaccines, to maternal antibodies-positive day-old broiler chicks did not restrict any protection produced against these viruses (Ball et al, 2019).…”

Pros and Cons on Use of Live Viral Vaccines in Commercial Chicken Flocks

“…In some countries, this has caused “super-crowded” vaccination schedules, resulting in frequent vaccinations and bird handling. For live viral vaccines, few studies have highlighted compatibility of co-administering NDV, IBV strains, and aMPV simultaneously (84,85), NDV and IBV (86), and NDV and IBD vaccines (87) within defined geographical regions. It is important to note that different combinations of live vaccines are required to combat different pathogens globally, which varies for different countries.…”