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Effect of passive immunization on immunogenicity and protective efficacy of vaccination against a Mexican low-pathogenic avian H5N2 influenza virus.

Forrest HL, Garcia A, Danner A, Seiler JP, Friedman K, Webster RG, Jones JC - Influenza Other Respir Viruses (2013)

Bottom Line: Booster doses of vaccine reduced the immunosuppressive effects of the administered sera.Vaccine efficacy against LP H5N2 in Mexico can be severely reduced by maternal antibodies.Source-dependent antisera effects offer the possibility of further elucidation of the immunosuppressive components involved.

View Article: PubMed Central - PubMed

Affiliation: Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA.

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Related in: MedlinePlus

Total number of animals per group that were infected post‐challenges as determined by virus shedding and seroelevation. A chicken was considered to be shedding if virus was isolated from oropharyngeal and/or cloacal swabs on at least one occurrence. A four‐fold increase in HI titer 14 days post‐challenge (compared to pre‐challenge titer) was considered to be seroelevation suggestive of infection. The total number of animals infected per group is the combined total of animals that were shedding and/or seroelevated after challenge. Groups are as described in Table 1. Group 1, n = 9; group 2, n = 9; group 3, n = 10; group 4, n = 11; group 5, n = 11; group 6, n = 10; group 7, n = 10; group 8, n =11.
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irv12140-fig-0001: Total number of animals per group that were infected post‐challenges as determined by virus shedding and seroelevation. A chicken was considered to be shedding if virus was isolated from oropharyngeal and/or cloacal swabs on at least one occurrence. A four‐fold increase in HI titer 14 days post‐challenge (compared to pre‐challenge titer) was considered to be seroelevation suggestive of infection. The total number of animals infected per group is the combined total of animals that were shedding and/or seroelevated after challenge. Groups are as described in Table 1. Group 1, n = 9; group 2, n = 9; group 3, n = 10; group 4, n = 11; group 5, n = 11; group 6, n = 10; group 7, n = 10; group 8, n =11.

Mentions: In addition to virus shedding, a four‐fold increase in HI titer 14 dpc was also suggestive of infection. All birds in the naïve group met these criteria, and 2 birds from the vaccine control group increased their titers after challenge (Figure 1). Of the experimental groups, group 6 (neat, field‐derived post‐vaccination antiserum) had the most animals that showed increased titers (n = 7), and group 3 (neat, laboratory‐derived post‐infection antiserum) had the fewest animals with increases (n = 3). Some of the animals in the vaccine control group and groups 3–5 showed increased HI titers, but did not shed after challenge. Although vaccination may not have been effective in preventing infection in these specific instances, it did eliminate viral shedding. If both seroelevation and virus shedding are taken as evidence of infection, then all birds passively immunized with field‐derived post‐vaccination antisera had evidence of infection, despite vaccination with or without boost.


Effect of passive immunization on immunogenicity and protective efficacy of vaccination against a Mexican low-pathogenic avian H5N2 influenza virus.

Forrest HL, Garcia A, Danner A, Seiler JP, Friedman K, Webster RG, Jones JC - Influenza Other Respir Viruses (2013)

Total number of animals per group that were infected post‐challenges as determined by virus shedding and seroelevation. A chicken was considered to be shedding if virus was isolated from oropharyngeal and/or cloacal swabs on at least one occurrence. A four‐fold increase in HI titer 14 days post‐challenge (compared to pre‐challenge titer) was considered to be seroelevation suggestive of infection. The total number of animals infected per group is the combined total of animals that were shedding and/or seroelevated after challenge. Groups are as described in Table 1. Group 1, n = 9; group 2, n = 9; group 3, n = 10; group 4, n = 11; group 5, n = 11; group 6, n = 10; group 7, n = 10; group 8, n =11.
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Related In: Results  -  Collection

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irv12140-fig-0001: Total number of animals per group that were infected post‐challenges as determined by virus shedding and seroelevation. A chicken was considered to be shedding if virus was isolated from oropharyngeal and/or cloacal swabs on at least one occurrence. A four‐fold increase in HI titer 14 days post‐challenge (compared to pre‐challenge titer) was considered to be seroelevation suggestive of infection. The total number of animals infected per group is the combined total of animals that were shedding and/or seroelevated after challenge. Groups are as described in Table 1. Group 1, n = 9; group 2, n = 9; group 3, n = 10; group 4, n = 11; group 5, n = 11; group 6, n = 10; group 7, n = 10; group 8, n =11.
Mentions: In addition to virus shedding, a four‐fold increase in HI titer 14 dpc was also suggestive of infection. All birds in the naïve group met these criteria, and 2 birds from the vaccine control group increased their titers after challenge (Figure 1). Of the experimental groups, group 6 (neat, field‐derived post‐vaccination antiserum) had the most animals that showed increased titers (n = 7), and group 3 (neat, laboratory‐derived post‐infection antiserum) had the fewest animals with increases (n = 3). Some of the animals in the vaccine control group and groups 3–5 showed increased HI titers, but did not shed after challenge. Although vaccination may not have been effective in preventing infection in these specific instances, it did eliminate viral shedding. If both seroelevation and virus shedding are taken as evidence of infection, then all birds passively immunized with field‐derived post‐vaccination antisera had evidence of infection, despite vaccination with or without boost.

Bottom Line: Booster doses of vaccine reduced the immunosuppressive effects of the administered sera.Vaccine efficacy against LP H5N2 in Mexico can be severely reduced by maternal antibodies.Source-dependent antisera effects offer the possibility of further elucidation of the immunosuppressive components involved.

View Article: PubMed Central - PubMed

Affiliation: Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA.

Show MeSH
Related in: MedlinePlus