Immunogenicity and protective efficacy of inactivated equine influenza (H3N8) virus vaccine in murine model

Protective efficacy of inactivated reverse genetics based equine influenza vaccine candidate adjuvanted with Montanide^TM Pet Gel in murine model

“…The antibody response in infection control mice (group B) was lower with an HAI titer of 18.67±4.46 at 5 dpc which increased to 69.33±12.84 at 14 dpc. Almost similar serological response was also found in previous studies [21]. The MPG adjuvant has been shown to influence the increase in antibody response of inactivated Rhodococcus equi vaccine in horses without any adverse effect [7].…”

“…Group B had very high copy numbers in the nasal washings on 1 and 3 dpc which correlated with lesions in trachea and turbinates (deciliation, desquamation of epithelium and presence of inflammatory cells in the lumen) that reached their maximum upto 3 dpc, while viral residual titer numbers which were detectable upto 5 dpc in the lungs relate with lesions (necrotizing erosive bronchiolitis and alveolitis) that were seen in maximum intensity upto 5 dpc in the lungs. Pavulraj et al [21] also had analogous EID50 values in nasal washings in the unimmunized group while a very low titer shedding of virus was observed on 1 dpc with in mice challenged with the H3N8 virus subsequent to immunization with inactivated virus adjuvanted with alum. Svitek et al [26] showed reduced viral load in nasal washes from 1 dpc onward before disappearing altogether on 6 dpc in ferrets challenged with H1N1 and H3N2 virus.…”

“…Therefore, we have shown that rgEIV with backbone of WSN/33(H1N1) provides adequate stimulation of immune responses indicated through HAI antibody titers as has also been documented by Bhatia et al [3] in chicken immunized with rgH5N2 and challenge with HPAI (H5N1). The rgEIV vaccine candidate also induced higher antibody response as compared to the aluminum hydroxide (Alum) adjuvanted inactivated whole EIV (H3N8) vaccine which generated an HAI titer of 138.67±22.69 in mice at 42 dpi [21]. The antibody response in infection control mice (group B) was lower with an HAI titer of 18.67±4.46 at 5 dpc which increased to 69.33±12.84 at 14 dpc.…”

“…Group C animals were not given any treatment and served as unimmunized -uninfected control ( Table 1). The vaccine dosage -15 μg of viral protein in immunodiffusion (SRD) content, total protein content of virus was utilized in the current study [20,21]. Group A mice were immunized with the vaccine formulation -15 μg of viral protein in μl intramuscularly on both the flanks on day 0 of the animal experimentation followed by booster doses -μg of viral protein on day 21 and 35 post immunization.…”

“…Total histopathological score. Grades of 0 to 5 were given for each of the parameters with 0 indicating no pathological change while 5 indicating severe histopathological changes as described in our previous studies [20,21].…”