Faculty Opinions recommendation of Antigenic and genetic characteristics of swine-origin 2009 A(H1N1) influenza viruses circulating in humans.

ABSTRACTIndividuals <60 years of age had the lowest incidence of infection, with ∼25% of these people having preexisting, cross-reactive antibodies to novel 2009 H1N1 influenza. Many people >60 years old also had preexisting antibodies to novel H1N1. These observations are puzzling because the seasonal H1N1 viruses circulating during the last 60 years were not antigenically similar to novel H1N1. We therefore hypothesized that a sequence of exposures to antigenically different seasonal H1N1 viruses can elicit an antibody response that protects against novel 2009 H1N1. Ferrets were preinfected with seasonal H1N1 viruses and assessed for cross-reactive antibodies to novel H1N1. Serum from infected ferrets was assayed for cross-reactivity to both seasonal and novel 2009 H1N1 strains. These results were compared to those of ferrets that were sequentially infected with H1N1 viruses isolated prior to 1957 or more-recently isolated viruses. Following seroconversion, ferrets were challenged with novel H1N1 influenza virus and assessed for viral titers in the nasal wash, morbidity, and mortality. There was no hemagglutination inhibition (HAI) cross-reactivity in ferrets infected with any single seasonal H1N1 influenza viruses, with limited protection to challenge. However, sequential H1N1 influenza infections reduced the incidence of disease and elicited cross-reactive antibodies to novel H1N1 isolates. The amount and duration of virus shedding and the frequency of transmission following novel H1N1 challenge were reduced. Exposure to multiple seasonal H1N1 influenza viruses, and not to any single H1N1 influenza virus, elicits a breadth of antibodies that neutralize novel H1N1 even though the host was never exposed to the novel H1N1 influenza viruses.

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Genetic Characteristics of Avian Influenza Virus Isolated from Wild Birds in South Korea, 2019–2020

Viruses ◽

10.3390/v13030381 ◽

2021 ◽

Vol 13 (3) ◽

pp. 381

Author(s):

Eun-Jee Na ◽

Young-Sik Kim ◽

Sook-Young Lee ◽

Yoon-Ji Kim ◽

Jun-Soo Park ◽

...

Keyword(s):

Avian Influenza ◽

South Korea ◽

Basic Amino Acid ◽

Histopathological Change ◽

Amino Acid Sequences ◽

Wild Birds ◽

Influenza Viruses ◽

Economic Losses ◽

Active Monitoring ◽

Genetic Characteristics

Wild aquatic birds, a natural reservoir of avian influenza viruses (AIVs), transmit AIVs to poultry farms, causing huge economic losses. Therefore, the prevalence and genetic characteristics of AIVs isolated from wild birds in South Korea from October 2019 to March 2020 were investigated and analyzed. Fresh avian fecal samples (3256) were collected by active monitoring of 11 wild bird habitats. Twenty-eight AIVs were isolated. Seven HA and eight NA subtypes were identified. All AIV hosts were Anseriformes species. The HA cleavage site of 20 representative AIVs was encoded by non-multi-basic amino acid sequences. Phylogenetic analysis of the eight segment genes of the AIVs showed that most genes clustered within the Eurasian lineage. However, the HA gene of H10 viruses and NS gene of four viruses clustered within the American lineage, indicating intercontinental reassortment of AIVs. Representative viruses likely to infect mammals were selected and evaluated for pathogenicity in mice. JB21-58 (H5N3), JB42-93 (H9N2), and JB32-81 (H11N2) were isolated from the lungs, but JB31-69 (H11N9) was not isolated from the lungs until the end of the experiment at 14 dpi. None of infected mice showed clinical sign and histopathological change in the lung. In addition, viral antigens were not detected in lungs of all mice at 14 dpi. These data suggest that LPAIVs derived from wild birds are unlikely to be transmitted to mammals. However, because LPAIVs can reportedly infect mammals, including humans, continuous surveillance and monitoring of AIVs are necessary, despite their low pathogenicity.

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Next Generation of Computationally Optimized Broadly Reactive HA Vaccines Elicited Cross-Reactive Immune Responses and Provided Protection against H1N1 Virus Infection

Vaccines ◽

10.3390/vaccines9070793 ◽

2021 ◽

Vol 9 (7) ◽

pp. 793

Author(s):

Ying Huang ◽

Monique S. França ◽

James D. Allen ◽

Hua Shi ◽

Ted M. Ross

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Immune Responses ◽

H1n1 Virus ◽

Influenza Virus Infection ◽

H1n1 Influenza ◽

Influenza Viruses ◽

Next Generation ◽

Wild Type ◽

Influenza A H1n1

Vaccination is the best way to prevent influenza virus infections, but the diversity of antigenically distinct isolates is a persistent challenge for vaccine development. In order to conquer the antigenic variability and improve influenza virus vaccine efficacy, our research group has developed computationally optimized broadly reactive antigens (COBRAs) in the form of recombinant hemagglutinins (rHAs) to elicit broader immune responses. However, previous COBRA H1N1 vaccines do not elicit immune responses that neutralize H1N1 virus strains in circulation during the recent years. In order to update our COBRA vaccine, two new candidate COBRA HA vaccines, Y2 and Y4, were generated using a new seasonal-based COBRA methodology derived from H1N1 isolates that circulated during 2013–2019. In this study, the effectiveness of COBRA Y2 and Y4 vaccines were evaluated in mice, and the elicited immune responses were compared to those generated by historical H1 COBRA HA and wild-type H1N1 HA vaccines. Mice vaccinated with the next generation COBRA HA vaccines effectively protected against morbidity and mortality after infection with H1N1 influenza viruses. The antibodies elicited by the COBRA HA vaccines were highly cross-reactive with influenza A (H1N1) pdm09-like viruses isolated from 2009 to 2021, especially with the most recent circulating viruses from 2019 to 2021. Furthermore, viral loads in lungs of mice vaccinated with Y2 and Y4 were dramatically reduced to low or undetectable levels, resulting in minimal lung injury compared to wild-type HA vaccines following H1N1 influenza virus infection.

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Origin of the European avian-like swine influenza viruses

Journal of General Virology ◽

10.1099/vir.0.068569-0 ◽

2014 ◽

Vol 95 (11) ◽

pp. 2372-2376 ◽

Cited By ~ 10

Author(s):

Andi Krumbholz ◽

Jeannette Lange ◽

Andreas Sauerbrei ◽

Marco Groth ◽

Matthias Platzer ◽

...

Keyword(s):

Avian Influenza ◽

Phylogenetic Trees ◽

Sequence Data ◽

Swine Influenza ◽

H1n1 Influenza ◽

Molecular Data ◽

Influenza Viruses ◽

Time Resolved ◽

Genotype Constellation ◽

Tree Inference

The avian-like swine influenza viruses emerged in 1979 in Belgium and Germany. Thereafter, they spread through many European swine-producing countries, replaced the circulating classical swine H1N1 influenza viruses, and became endemic. Serological and subsequent molecular data indicated an avian source, but details remained obscure due to a lack of relevant avian influenza virus sequence data. Here, the origin of the European avian-like swine influenza viruses was analysed using a collection of 16 European swine H1N1 influenza viruses sampled in 1979–1981 in Germany, the Netherlands, Belgium, Italy and France, as well as several contemporaneous avian influenza viruses of various serotypes. The phylogenetic trees suggested a triple reassortant with a unique genotype constellation. Time-resolved maximum clade credibility trees indicated times to the most recent common ancestors of 34–46 years (before 2008) depending on the RNA segment and the method of tree inference.

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In vitro and in vivo characterization of new swine-origin H1N1 influenza viruses

Nature ◽

10.1038/nature08260 ◽

2009 ◽

Vol 460 (7258) ◽

pp. 1021-1025 ◽

Cited By ~ 763

Author(s):

Yasushi Itoh ◽

Kyoko Shinya ◽

Maki Kiso ◽

Tokiko Watanabe ◽

Yoshihiro Sakoda ◽

...

Keyword(s):

H1n1 Influenza ◽

Influenza Viruses ◽

In Vivo Characterization

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MOLECULAR AND GENETIC CHARACTERISTICS OF SURFACE AND NONSTRUCTURE PROTEINS OF PANDEMIC INFLUENZA VIRUSES A(H1N1)PDM09 IN 2015-2016 EPIDEMIC SEASON

Bulletin of Taras Shevchenko National University of Kyiv Series Biology ◽

10.17721/1728_2748.2016.72.44-48 ◽

2016 ◽

Vol 72 (2) ◽

pp. 44-48

Author(s):

O. Smutko ◽

L. Radchenko ◽

A. Mironenko

Keyword(s):

Amino Acid ◽

Pandemic Influenza ◽

Influenza A ◽

Phylogenetic Trees ◽

Influenza Viruses ◽

Amino Acid Substitutions ◽

Ns1 Protein ◽

Genetic Characteristics ◽

Epidemic Season ◽

Influenza A H1n1

The aim of the present study was identifying of molecular and genetic changes in hemaglutinin (HA), neuraminidase (NA) and non-structure protein (NS1) genes of pandemic influenza A(H1N1)pdm09 strains, that circulated in Ukraine during 2015-2016 epidemic season. Samples (nasopharyngeal swabs from patients) were analyzed using real-time polymerase chain reaction (RTPCR). Phylogenetic trees were constructed using MEGA 7 software. 3D structures were constructed in Chimera 1.11.2rc software. Viruses were collected in 2015-2016 season fell into genetic group 6B and in two emerging subgroups, 6B.1 and 6B.2 by gene of HA and NA. Subgroups 6B.1 and 6B.2 are defined by the following amino acid substitutions. In the NS1 protein were identified new amino acid substitutions D2E, N48S, and E125D in 2015-2016 epidemic season. Specific changes were observed in HA protein antigenic sites, but viruses saved similarity to vaccine strain. NS1 protein acquired substitution associated with increased virulence of the influenza virus.

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