1
|
Vandoorn E, Stadejek W, Leroux-Roels I, Leroux-Roels G, Parys A, Van Reeth K. Human Immunity and Susceptibility to Influenza A(H3) Viruses of Avian, Equine, and Swine Origin. Emerg Infect Dis 2023; 29:98-109. [PMID: 36573615 PMCID: PMC9796212 DOI: 10.3201/eid2901.220943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Influenza A viruses (IAVs) of subtype H3 that infect humans are antigenically divergent from those of birds, horses, and swine. Human immunity against these viruses might be limited, implying potential pandemic risk. To determine human risk, we selected 4 avian, 1 equine, and 3 swine IAVs representing major H3 lineages. We tested serum collected during 2017-2018 from 286 persons in Belgium for hemagglutination inhibiting antibodies and virus neutralizing antibodies against those animal-origin IAVs and tested replication in human airway epithelia. Seroprevalence rates for circulating IAVs from swine in North America were >51%, swine in Europe 7%-37%, and birds and equids ≤12%. Replication was efficient for cluster IV-A IAVs from swine in North America and IAVs from swine in Europe, intermediate for IAVs from horses and poultry, and absent for IAVs from wild birds and a novel human-like swine IAV in North America. Public health risk may be highest for swine H3 IAVs.
Collapse
|
2
|
Genetic Diversity of the Hemagglutinin Genes of Influenza a Virus in Asian Swine Populations. Viruses 2022; 14:v14040747. [PMID: 35458477 PMCID: PMC9032595 DOI: 10.3390/v14040747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 01/04/2023] Open
Abstract
Swine influenza (SI) is a major respiratory disease of swine; SI is due to the influenza A virus of swine (IAV-S), a highly contagious virus with zoonotic potential. The intensity of IAV-S surveillance varies among countries because it is not a reportable disease and causes limited mortality in swine. Although Asia accounts for half of all pig production worldwide, SI is not well managed in those countries. Rigorously managing SI on pig farms could markedly reduce the economic losses, the likelihood of novel reassortants among IAV-S, and the zoonotic IAV-S infections in humans. Vaccination of pigs is a key control measure for SI, but its efficacy relies on the optimal antigenic matching of vaccine strains with the viral strains circulating in the field. Here, we phylogenetically reviewed the genetic diversity of the hemagglutinin gene among IAVs-S that have circulated in Asia during the last decade. This analysis revealed the existence of country-specific clades in both the H1 and H3 subtypes and cross-border transmission of IAVs-S. Our findings underscore the importance of choosing vaccine antigens for each geographic region according to both genetic and antigenic analyses of the circulating IAV-S to effectively manage SI in Asia.
Collapse
|
3
|
Vandoorn E, Leroux-Roels I, Leroux-Roels G, Parys A, Vincent A, Van Reeth K. Detection of H1 Swine Influenza A Virus Antibodies in Human Serum Samples by Age Group 1. Emerg Infect Dis 2021; 26:2118-2128. [PMID: 32818398 PMCID: PMC7454048 DOI: 10.3201/eid2609.191796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Most H1 influenza A viruses (IAVs) of swine are derived from past human viruses. As human population immunity against these IAVs gradually decreases, the risk of reintroduction to humans increases. We examined 549 serum samples from persons 0-97 years of age collected in Belgium during 2017-2018 for hemagglutination inhibiting and virus neutralizing antibodies against 7 major H1 swine IAV (swIAV) clades and 3 human progenitor IAVs. Seroprevalence (titers >40) rates were >50% for classical swine and European human-like swIAVs, >24% for North American human-like δ1a and Asian avian-like swIAVs, and <10% for North American human-like δ1b and European avian-like swIAVs, but rates were age-dependent. Antibody titers against human-like swIAVs and supposed human precursor IAVs correlated with correlation coefficients of 0.30-0.86. Our serologic findings suggest that European avian-like, clade 1C.2.1, and North American human-like δ1b, clade 1B.2.2.2, H1 swIAVs pose the highest pandemic risk.
Collapse
|
4
|
Liu F, Levine MZ. Heterologous Antibody Responses Conferred by A(H3N2) Variant and Seasonal Influenza Vaccination Against Newly Emerged 2016-2018 A(H3N2) Variant Viruses in Healthy Persons. Clin Infect Dis 2021; 71:3061-3070. [PMID: 31858129 DOI: 10.1093/cid/ciz1203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Swine origin A(H3N2) variant [A(H3N2)v] viruses continue to evolve and remain a public health threat. Recent outbreaks in humans in 2016-2018 were caused by a newly emerged A(H3N2)v cluster 2010.1, which are genetically and antigenically distinct from the previously predominant cluster IV. To address the public health risk, we evaluated the levels of heterologous cross-reactive antibodies to A(H3N2)v cluster 2010.1 viruses induced from an existing cluster IV A(H3N2)v vaccine and several seasonal inactivated influenza vaccines (IIVs) in adults, elderly individuals, and children. METHODS Human vaccine sera and ferret antisera were analyzed by hemagglutination inhibition (HI) and neutralization assays against representative A(H3N2)v viruses from clusters IV and 2010.1 and seasonal A(H3N2) viruses. RESULTS Ferret antisera detected no or little cross-reactivity between the 2 A(H3N2)v clusters or between A(H3N2)v and seasonal A(H3N2) viruses. In humans, cluster IV A(H3N2)v vaccine induced antibodies cross-reactive to cluster 2010.1 viruses in approximately one-third of the 89 adult and elderly vaccinees. Seasonal IIVs did not induce seroprotective antibodies (≥40) to A(H3N2)v viruses in young children, but induced higher antibodies to A(H3N2)v viruses in cluster 2010.1 than those in cluster IV in adults. CONCLUSIONS Cluster IV A(H3N2)v vaccine did not provide sufficient heterologous antibody responses against the new 2010.1 cluster A(H3N2)v viruses. Seasonal IIV could not induce seroprotective antibodies to 2010.1 cluster A(H3N2)v viruses in young children, suggesting that young children are still at high risk to the newly emerged A(H3N2)v viruses. Continued surveillance on A(H3N2)v viruses is critical for risk assessment and pandemic preparedness.
Collapse
Affiliation(s)
- Feng Liu
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Min Z Levine
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| |
Collapse
|
5
|
Liu F, Veguilla V, Gross FL, Gillis E, Rowe T, Xu X, Tumpey TM, Katz JM, Levine MZ, Lu X. Effect of Priming With Seasonal Influenza A(H3N2) Virus on the Prevalence of Cross-Reactive Hemagglutination-Inhibition Antibodies to Swine-Origin A(H3N2) Variants. J Infect Dis 2017; 216:S539-S547. [PMID: 28934461 DOI: 10.1093/infdis/jix093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Recent outbreaks of swine-origin influenza A(H3N2) variant (H3N2v) viruses have raised public health concerns. Previous studies indicated that older children and young adults had the highest levels of hemagglutination-inhibition (HI) antibodies to 2010-2011 H3N2v viruses. However, newly emerging 2013 H3N2v have acquired antigenic mutations in the hemagglutinin at amino acid position 145 (N145K/R). We estimated the levels of serologic cross-reactivity among humans primed with seasonal influenza A(H3N2) (sH3N2), using postinfection ferret antisera. We also explored age-related HI antibody responses to 2012-2013 H3N2v viruses. Methods Human and ferret antisera were tested in HI assays against 1 representative 2012 H3N2v (145N) and 2 2013 H3N2v (145K/R) viruses, together with 9 sH3N2 viruses circulating since 1968. Results Low levels of cross-reactivity between the H3N2v and sH3N2 viruses from the 1970s-1990s were observed using postinfection ferret antisera. The overall seroprevalence among the sH3N2-primed population against 2012-2013 H3N2v viruses was >50%, and age-related seroprevalence was observed. Seroprevalence was significantly higher to 2013 H3N2v than to 2012 H3N2v viruses among some children likely to have been primed with A/Sydney/5/97-like (145K) or A/Wuhan/359/95-like viruses (145K). Conclusions A single substitution (N145K/R) was sufficient to affect seropositivity to H3N2v viruses in some individuals. Insight into age-related antibody responses to newly emerging H3N2v viruses is critical for risk assessment and pandemic preparedness.
Collapse
Affiliation(s)
- Feng Liu
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Vic Veguilla
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - F Liaini Gross
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Gillis
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Thomas Rowe
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Xiyan Xu
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Terrence M Tumpey
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jacqueline M Katz
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Min Z Levine
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Xiuhua Lu
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| |
Collapse
|
6
|
Van Reeth K, Gracia JCM, Trus I, Sys L, Claes G, Versnaeyen H, Cox E, Krammer F, Qiu Y. Heterologous prime-boost vaccination with H3N2 influenza viruses of swine favors cross-clade antibody responses and protection. NPJ Vaccines 2017; 2. [PMID: 29250437 PMCID: PMC5604745 DOI: 10.1038/s41541-017-0012-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The emergence of multiple novel lineages of H1 and H3 influenza A viruses in swine has confounded control by inactivated vaccines. Because of substantial genetic and geographic heterogeneity among circulating swine influenza viruses, one vaccine strain per subtype cannot be efficacious against all of the current lineages. We have performed vaccination-challenge studies in pigs to examine whether priming and booster vaccinations with antigenically distinct H3N2 swine influenza viruses could broaden antibody responses and protection. We prepared monovalent whole inactivated, adjuvanted vaccines based on a European and a North American H3N2 swine influenza virus, which showed 81.5% aa homology in the HA1 region of the hemagglutinin and 83.4% in the neuraminidase. Our data show that (i) Priming with European and boosting with North American H3N2 swine influenza virus induces antibodies and protection against both vaccine strains, unlike prime-boost vaccination with a single virus or a single administration of bivalent vaccine. (ii) The heterologous prime-boost vaccination enhances hemagglutination inhibiting, virus neutralizing and neuraminidase inhibiting antibody responses against H3N2 viruses that are antigenically distinct from both vaccine strains. Antibody titers to the most divergent viruses were higher than after two administrations of bivalent vaccine. (iii) However, it does not induce antibodies to the conserved hemagglutinin stalk or to other hemagglutinin subtypes. We conclude that heterologous prime-boost vaccination might broaden protection to H3N2 swine influenza viruses and reduce the total amount of vaccine needed. This strategy holds potential for vaccination against influenza viruses from both humans and swine and for a better control of (reverse) zoonotic transmission of influenza viruses.
Collapse
Affiliation(s)
- Kristien Van Reeth
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | | | - Ivan Trus
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | - Lieve Sys
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | - Gerwin Claes
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | - Han Versnaeyen
- Laboratory of Pathology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | - Eric Cox
- Laboratory of Immunology, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium
| | - Florian Krammer
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yu Qiu
- OIE Sub-Regional Representation for South-East Asia, Bangkok, Thailand
| |
Collapse
|
7
|
Qiu Y, De Hert K, Van Reeth K. Cross-protection against European swine influenza viruses in the context of infection immunity against the 2009 pandemic H1N1 virus: studies in the pig model of influenza. Vet Res 2015; 46:105. [PMID: 26404790 PMCID: PMC4581489 DOI: 10.1186/s13567-015-0236-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 08/06/2015] [Indexed: 12/31/2022] Open
Abstract
Pigs are natural hosts for the same influenza virus subtypes as humans and are a valuable model for cross-protection studies with influenza. In this study, we have used the pig model to examine the extent of virological protection between a) the 2009 pandemic H1N1 (pH1N1) virus and three different European H1 swine influenza virus (SIV) lineages, and b) these H1 viruses and a European H3N2 SIV. Pigs were inoculated intranasally with representative strains of each virus lineage with 6- and 17-week intervals between H1 inoculations and between H1 and H3 inoculations, respectively. Virus titers in nasal swabs and/or tissues of the respiratory tract were determined after each inoculation. There was substantial though differing cross-protection between pH1N1 and other H1 viruses, which was directly correlated with the relatedness in the viral hemagglutinin (HA) and neuraminidase (NA) proteins. Cross-protection against H3N2 was almost complete in pigs with immunity against H1N2, but was weak in H1N1/pH1N1-immune pigs. In conclusion, infection with a live, wild type influenza virus may offer substantial cross-lineage protection against viruses of the same HA and/or NA subtype. True heterosubtypic protection, in contrast, appears to be minimal in natural influenza virus hosts. We discuss our findings in the light of the zoonotic and pandemic risks of SIVs.
Collapse
Affiliation(s)
- Yu Qiu
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
| | - Karl De Hert
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
| | - Kristien Van Reeth
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
| |
Collapse
|