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Published ahead of print 2 October 2013, doi: 10.1128/JVI.02434-13 JVI.02434-13
Impact of prior seasonal H3N2 influenza vaccination or infection on protection and transmission of emerging variants of influenza A(H3N2)v virus in ferrets
Katherine V. Housera,b,
Melissa B. Pearcea,
Jacqueline M. Katza and
Terrence M. Tumpeya⇑
+ Author Affiliations
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USAa
Graduate Program in Immunology and Molecular Pathogenesis of the Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia, USAb
ABSTRACT
Influenza H3N2 A viruses continue to circulate in swine and occasionally infect humans, resulting in outbreaks of variant influenza H3N2 [A(H3N2)v]. It has been previously demonstrated in ferrets that A(H3N2)v viruses transmit as efficiently as seasonal influenza viruses, raising concern over the pandemic potential of these viruses. However, A(H3N2)v viruses have not acquired the ability to transmit efficiently among humans, which may be due in part to existing cross-reactive immunity to A(H3N2)v viruses. Although current seasonal H3N2 and A(H3N2)v viruses are antigenically distinct from one another, historical H3N2 viruses share some antigenic similarity to A(H3N2)v viruses and previous exposure to these viruses may provide a measure of immune protection sufficient to dampen A(H3N2)v virus transmission. Here, we evaluated whether prior seasonal H3N2 influenza vaccination or infection affects virus replication and transmission of A(H3N2)v virus in the ferret animal model.
We found that the seasonal trivalent inactivated influenza vaccine (TIV) or a monovalent vaccine prepared from an antigenically related 1992 seasonal influenza H3N2 (A/Beijing/32/92) virus failed to substantially reduce A(H3N2)v (A/Indiana/08/2011) virus shedding and subsequent transmission to naïve hosts.
Conversely, ferrets primed by seasonal H3N2 virus infection displayed reduced A(H3N2)v virus shedding following challenge which blunted transmission to naïve ferrets. A higher level of specific IgG and IgA titers antibodies detected among infected versus vaccinated ferrets was associated with the degree of protection offered by seasonal H3N2 virus infection. The data demonstrate in ferrets that the efficiency of A(H3N2)v transmission is disrupted by pre-existing immunity induced by seasonal H3N2 virus infection.
http://jvi.asm.org/content/early/2013/09/26/JVI.02434-13.abstract
Impact of prior seasonal H3N2 influenza vaccination or infection on protection and transmission of emerging variants of influenza A(H3N2)v virus in ferrets
Katherine V. Housera,b,
Melissa B. Pearcea,
Jacqueline M. Katza and
Terrence M. Tumpeya⇑
+ Author Affiliations
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USAa
Graduate Program in Immunology and Molecular Pathogenesis of the Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia, USAb
ABSTRACT
Influenza H3N2 A viruses continue to circulate in swine and occasionally infect humans, resulting in outbreaks of variant influenza H3N2 [A(H3N2)v]. It has been previously demonstrated in ferrets that A(H3N2)v viruses transmit as efficiently as seasonal influenza viruses, raising concern over the pandemic potential of these viruses. However, A(H3N2)v viruses have not acquired the ability to transmit efficiently among humans, which may be due in part to existing cross-reactive immunity to A(H3N2)v viruses. Although current seasonal H3N2 and A(H3N2)v viruses are antigenically distinct from one another, historical H3N2 viruses share some antigenic similarity to A(H3N2)v viruses and previous exposure to these viruses may provide a measure of immune protection sufficient to dampen A(H3N2)v virus transmission. Here, we evaluated whether prior seasonal H3N2 influenza vaccination or infection affects virus replication and transmission of A(H3N2)v virus in the ferret animal model.
We found that the seasonal trivalent inactivated influenza vaccine (TIV) or a monovalent vaccine prepared from an antigenically related 1992 seasonal influenza H3N2 (A/Beijing/32/92) virus failed to substantially reduce A(H3N2)v (A/Indiana/08/2011) virus shedding and subsequent transmission to naïve hosts.
Conversely, ferrets primed by seasonal H3N2 virus infection displayed reduced A(H3N2)v virus shedding following challenge which blunted transmission to naïve ferrets. A higher level of specific IgG and IgA titers antibodies detected among infected versus vaccinated ferrets was associated with the degree of protection offered by seasonal H3N2 virus infection. The data demonstrate in ferrets that the efficiency of A(H3N2)v transmission is disrupted by pre-existing immunity induced by seasonal H3N2 virus infection.
http://jvi.asm.org/content/early/2013/09/26/JVI.02434-13.abstract
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