#Tissue #tropisms opt for transmissible #reassortants during #avian and #swine #influenza A virus co-infection in swine (PLoS Pathogens, abstract)

[Source: PLoS Pathogens, full page: (LINK). Abstract, edited.]


Tissue tropisms opt for transmissible reassortants during avian and swine influenza A virus co-infection in swine

Xiaojian Zhang , Hailiang Sun , Fred L. Cunningham , Lei Li , Katie Hanson-Dorr, Matthew W. Hopken, Jim Cooley, Li-Ping Long, John A. Baroch, Tao Li, Brandon S. Schmit, Xiaoxu Lin, Alicia K. Olivier,  [ … ], Xiu-Feng Wan

Published: December 3, 2018 / DOI: https://doi.org/10.1371/journal.ppat.1007417 / This is an uncorrected proof.



Genetic reassortment between influenza A viruses (IAVs) facilitate emergence of pandemic strains, and swine are proposed as a “mixing vessel” for generating reassortants of avian and mammalian IAVs that could be of risk to mammals, including humans. However, how a transmissible reassortant emerges in swine are not well understood. Genomic analyses of 571 isolates recovered from nasal wash samples and respiratory tract tissues of a group of co-housed pigs (influenza-seronegative, avian H1N1 IAV–infected, and swine H3N2 IAV–infected pigs) identified 30 distinct genotypes of reassortants. Viruses recovered from lower respiratory tract tissues had the largest genomic diversity, and those recovered from turbinates and nasal wash fluids had the least. Reassortants from lower respiratory tracts had the largest variations in growth kinetics in respiratory tract epithelial cells, and the cold temperature in swine nasal cells seemed to select the type of reassortant viruses shed by the pigs. One reassortant in nasal wash samples was consistently identified in upper, middle, and lower respiratory tract tissues, and it was confirmed to be transmitted efficiently between pigs. Study findings suggest that, during mixed infections of avian and swine IAVs, genetic reassortments are likely to occur in the lower respiratory track, and tissue tropism is an important factor selecting for a transmissible reassortant.


Author summary

Genetic reassortments between avian and swine influenza viruses are likely to occur in the swine lower respiratory track, and tissue tropism is an important factor selecting for a transmissible reassortant; determination of tissue tropisms for potential reassortants between contemporary avian and swine influenza viruses would help identify transmissible reassortants with public health risks.


Citation: Zhang X, Sun H, Cunningham FL, Li L, Hanson-Dorr K, Hopken MW, et al. (2018) Tissue tropisms opt for transmissible reassortants during avian and swine influenza A virus co-infection in swine. PLoS Pathog 14(12): e1007417. https://doi.org/10.1371/journal.ppat.1007417

Editor: Anice C. Lowen, Emory University School of Medicine, UNITED STATES

Received: July 24, 2018; Accepted: October 18, 2018; Published: December 3, 2018

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Data Availability: The sequence of A/swine/Texas/A01104013/2012 (H3N2) and A/mallard/Wisconsin/A00751454/2009 (H1N1) viruses are available from Genbank under the accession numbers JX280447 to JX280454 and MH879773 to MH879780. All other relevant data are included in the main text of this paper or the Supporting Information files associated with this paper.

Funding: This study was supported by the U.S. Department of Agriculture and the National Institutes of Health (NIH) [grant number R21AI135820]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Avian Influenza; Swine Influenza; Influenza A; H1N1; H3N2 Pigs; Reassortant strain.



Duration of #fever and other symptoms after the inhalation of #laninamivir octanoate hydrate in the 2016/17 #Japanese #influenza season; comparison with the 2011/12 to 2015/16 seasons (J Infect Chemother., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

J Infect Chemother. 2018 Sep;24(9):718-724. doi: 10.1016/j.jiac.2018.04.013. Epub 2018 Jun 1.

Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate in the 2016/17 Japanese influenza season; comparison with the 2011/12 to 2015/16 seasons.

Ikematsu H1, Kawai N2, Iwaki N2, Kashiwagi S2, Ishikawa Y3, Yamaguchi H3, Shiosakai K3.

Author information: 1 Japan Physicians Association, Tokyo, Japan. Electronic address: ikematsu@gray.plala.or.jp. 2 Japan Physicians Association, Tokyo, Japan. 3 Daiichi Sankyo Co., Ltd, Tokyo, Japan.



The duration of fever and symptoms after laninamivir octanoate hydrate (laninamivir) inhalation were investigated in the Japanese 2016/17 influenza season and the results were compared with those of the 2011/12 to 2015/16 seasons. A total of 1278 patients were evaluated for the duration of fever and symptoms in the six studied seasons. In the 2016/17 season, the influenza types/subtypes of the patients were 6 A (H1N1)pdm09 (2.9%), 183 A (H3N2) (87.6%), and 20 B (9.6%). The respective median durations of fever for A (H1N1)pdm09, A (H3N2), and B were 38.0, 33.0, and 38.5 h, without significant difference (p = 0.9201), and the median durations of symptoms were 86.5, 73.0, and 99.0 h, with significant difference (p = 0.0342). The median durations of fever and symptoms after laninamivir inhalation were quite consistent for the six studied seasons for A (H1N1)pdm09, A (H3N2), and B, without any significant differences. The percentage of patients with unresolved fever patients displayed a similar pattern through the six studied seasons for all these virus types. There was no significant difference in the duration of fever or symptoms between the Victoria and Yamagata lineages in the 2016/17 season and those of the previous studied seasons. Over the seasons tested, ten adverse drug reactions (ADRs) were reported from 1341 patients. The most frequent ADR was diarrhea and all ADRs were self-resolving and not serious. These results indicate the continuing clinical effectiveness of laninamivir against influenza A (H1N1)pdm09, A (H3N2), and B, with no safety issues.

KEYWORDS: Fever; Influenza; Laninamivir; Neuraminidase inhibitor; Symptom

PMID: 29861186 DOI: 10.1016/j.jiac.2018.04.013 [Indexed for MEDLINE]  Free full text

Keywords: Seasonal Influenza; H1N1pdm09; H3N2; Antivirals; Laninamivir; Japan.


The #Antihistamine Drugs #Carbinoxamine Maleate and #Chlorpheniramine Maleate Exhibit Potent #Antiviral Activity Against a Broad Spectrum of #Influenza Viruses (Front Microbiol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Front Microbiol. 2018 Nov 6;9:2643. doi: 10.3389/fmicb.2018.02643. eCollection 2018.

The Antihistamine Drugs Carbinoxamine Maleate and Chlorpheniramine Maleate Exhibit Potent Antiviral Activity Against a Broad Spectrum of Influenza Viruses.

Xu W1, Xia S1, Pu J1, Wang Q1, Li P1, Lu L1, Jiang S1,2.

Author information: 1 Shanghai Public Health Clinical Center and School of Basic Medical Sciences, Key Laboratory of Medical Molecular Virology of MOE/MOH, Fudan University, Shanghai, China. 2 Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States.



Influenza A viruses (IAV) comprise some of the most common infectious pathogens in humans, and they cause significant mortality and morbidity in immunocompromised people as well as children and the elderly. After screening an FDA-approved drug library containing 1280 compounds by cytopathic effect (CPE) reduction assay using the Cell Counting Kit-8, we found two antihistamines, carbinoxamine maleate (CAM) and S-(+)-chlorpheniramine maleate (SCM) with potent antiviral activity against A/Shanghai/4664T/2013(H7N9) infection with IC50(half-maximal inhibitory concentration) of 3.56 and 11.84 μM, respectively. Further studies showed that CAM and SCM could also inhibit infection by other influenza A viruses, including A/Shanghai/37T/2009(H1N1), A/Puerto Rico/8/1934(H1N1), A/Guizhou/54/1989(H3N2), and one influenza B virus, B/Shanghai/2017(BY). Mice were challenged intranasally with A/H7N9/4664T/2013 (H7N9) virus and intraperitoneally injected with CAM (10 mg/kg per day) or SCM (1 mg/kg per day) for 5 days. CAM or SCM (10 mg/kg per day) were fully protected against challenge with A/Shanghai/4664T/2013(H7N9). The results from mechanistic studies indicate that both could inhibit influenza virus infection by blocking viral entry into the target cell, the early stage of virus life cycle. However, CAM and SCM neither blocked virus attachment, characteristic of HA activity, nor virus release, characteristic of NA activity. Such data suggest that these two compounds may interfere with the endocytosis process. Thus, we have identified two FDA-approved antihistamine drugs, CAM and SCM, which can be repurposed for inhibiting infection by divergent influenza A strains and one influenza B strain with potential to be used for treatment and prevention of influenza virus infection.

KEYWORDS: antihistamine; carbinoxamine; chlorpheniramine; influenza virus; viral entry

PMID: 30459739 PMCID: PMC6232386 DOI: 10.3389/fmicb.2018.02643

Keywords: Influenza A; Avian Influenza; H7N9; H1N1; H3N2; Antivirals; Carbinoxamine; Chlorpheniramine; Animal models.


Elicitation of protective #antibodies against 20 years of future #H3N2 co-ciruculating #influenza virus variants in ferrets preimmune to historical H3N2 influenza viruses (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Elicitation of protective antibodies against 20 years of future H3N2 co-ciruculating influenza virus variants in ferrets preimmune to historical H3N2 influenza viruses.

James D. Allen, Hyesun Jang, Joshua DiNapoli, Harold Kleanthous, Ted M. Ross

DOI: 10.1128/JVI.00946-18



The vast majority of people already have pre-existing immune responses to influenza viruses from one or more subtypes. However, almost all preclinical studies evaluate new influenza vaccine candidates in immunologically naïve animals. Recently, our group demonstrated that priming naive ferrets with broadly reactive H1 COBRA HA based vaccines boosted pre-existing antibodies induced by wild-type H1N1 virus infections. These H1 COBRA HA antigens induced antibodies with HAI activity against multiple antigenically different H1N1 viral variants. In this study, ferrets, preimmune to historical H3N2 viruses, were vaccinated with virus-like particle (VLP) vaccines expressing either an HA from a wild-type H3 influenza virus or a COBRA H3 HA antigen (T6, T7, T10, or T11). The elicited antisera had the ability to neutralize virus infection against a panel of viruses representing vaccine strains selected by the World Health Organization (WHO), or a set of viral variants that co-circulated during the same time period. Preimmune animals vaccinated with H3 COBRA T10 HA antigen elicited sera with higher HAI antibody titers than antisera elicited by VLP vaccines with wild-type HA VLPs in preimmune ferrets. However, while the T11 COBRA vaccine did not elicit HAI activity, the elicited antibodies did neutralize antigenically distinct H3N2 influenza viruses. Overall, H3 COBRA-based HA vaccines were able to neutralize both historical H3 and comtemporary, as well as future H3N2 viruses with higher titers than vaccines with wild-type H3 HA antigens. This is the first report demonstrating the effectiveness of a broadly reactive H3N3 vaccine in a preimmune ferret model.



Following influenza virus exposure, the host generates neutralizing anti-hemagglutinin antibodies against that specific infecting influenza strain. These antibodies can also neutralize some, but not all, co-circulating strains. The goal of next generation influenza vaccines, such as HA head-based COBRA, is to stimulate broadly protective neutralizing antibodies against all strains circulating within a subtype, in particular those that persist over multiple influenza seasons, without requiring an update to the vaccine. To mimic the human condition, COBRA HA virus-like particle vaccines were tested in ferrets that were previously exposed to historical H3N2 influenza viruses. In this model, these vaccines elicited broadly protective antibodies that neutralized co-circulating H3N2 influenza viruses isolated over a 20-year period. This is the first study to show the effectiveness of H3N3 COBRA HA vaccines in a host with pre-existing immunity to influenza.

Copyright © 2018 American Society for Microbiology. All Rights Reserved.

Keywords: Influenza A; H3N2; H3N3; H1N1; Vaccines.


#Canine #Influenza Virus A(#H3N2) Clade with #Antigenic Variation, #China, 2016–2017 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 1—January 2019 / Dispatch

Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016–2017

Yanli Lyu1, Shikai Song1, Liwei Zhou1, Guoxia Bing, Qian Wang, Haoran Sun, Mingyue Chen, Junyi Hu, Mingyang Wang, Honglei Sun, Juan Pu, Zhaofei Xia, Jinhua Liu, and Yipeng Sun

Author affiliations: China Agricultural University, Beijing, China (Y. Lyu, S. Song, L. Zhou, Q. Wang, Haoran Sun, M. Chen, J. Hu, M. Wang, Honglei Sun, J. Pu, Z. Xia, J. Liu, Y. Sun); China Animal Disease Control Center, Beijing (G. Bing)



During 2012–2017, we collected throat swabs from dogs in China to characterize canine influenza virus (CIV) A(H3N2) isolates. A new antigenically and genetically distinct CIV H3N2 clade possessing mutations associated with mammalian adaptation emerged in 2016 and replaced previously circulating strains. This clade probably poses a risk for zoonotic infection.

Keywords: Canine Avian Influenza; Dogs; China; H3N2.


Cross- #Protective Immune Responses Induced by Sequential #Influenza Virus #Infection and by Sequential #Vaccination With Inactivated Influenza Vaccines (Front Immunol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Front Immunol. 2018 Oct 9;9:2312. doi: 10.3389/fimmu.2018.02312. eCollection 2018.

Cross-Protective Immune Responses Induced by Sequential Influenza Virus Infection and by Sequential Vaccination With Inactivated Influenza Vaccines.

Dong W1,2, Bhide Y1, Sicca F1, Meijerhof T1, Guilfoyle K3, Engelhardt OG3, Boon L4, de Haan CAM5, Carnell G6, Temperton N6, de Vries-Idema J1, Kelvin D2,7, Huckriede A1.

Author information: 1 Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands. 2 Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, Shantou, China. 3 National Institute for Biological Standards and Controls, Medicines and Healthcare Products Regulatory Agency, Potters Bar, United Kingdom. 4 Bioceros, Utrecht, Netherlands. 5 Virology Division, Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands. 6 Viral Pseudotype Unit, Medway School of Pharmacy, University of Kent, Chatham Maritime, Kent, United Kingdom. 7 Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.



Sequential infection with antigenically distinct influenza viruses induces cross-protective immune responses against heterologous virus strains in animal models. Here we investigated whether sequential immunization with antigenically distinct influenza vaccines can also provide cross-protection. To this end, we compared immune responses and protective potential against challenge with A(H1N1)pdm09 in mice infected sequentially with seasonal A(H1N1) virus followed by A(H3N2) virus or immunized sequentially with whole inactivated virus (WIV) or subunit (SU) vaccine derived from these viruses. Sequential infection provided solid cross-protection against A(H1N1)pdm09 infection while sequential vaccination with WIV, though not capable of preventing weight loss upon infection completely, protected the mice from reaching the humane endpoint. In contrast, sequential SU vaccination did not prevent rapid and extensive weight loss. Protection correlated with levels of cross-reactive but non-neutralizing antibodies of the IgG2a subclass, general increase of memory T cells and induction of influenza-specific CD4+ and CD8+ T cells. Adoptive serum transfer experiments revealed that despite lacking neutralizing activity, serum antibodies induced by sequential infection protected mice from weight loss and vigorous virus growth in the lungs upon A(H1N1)pdm09 virus challenge. Antibodies induced by WIV vaccination alleviated symptoms but could not control virus growth in the lung. Depletion of T cells prior to challenge revealed that CD8+ T cells, but not CD4+ T cells, contributed to cross-protection. These results imply that sequential immunization with WIV but not SU derived from antigenically distinct viruses could alleviate the severity of infection caused by a pandemic and may improve protection to unpredictable seasonal infection.

KEYWORDS: antigenically distinct influenza virus strains; cross-protection; immune mechanism; non-neutralizing antibody; sequential vaccination

PMID: 30356772 PMCID: PMC6189474 DOI: 10.3389/fimmu.2018.02312

Keywords: Influenza A; Vaccines; H1N1pdm09; H3N2; Animal Models.


N-Glycosylation of Seasonal #Influenza #Vaccine #Hemagglutinins: Implication for potency testing and immune processing (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

N-Glycosylation of Seasonal Influenza Vaccine Hemagglutinins: Implication for potency testing and immune processing

Yanming An, Lisa M. Parsons, Ewa Jankowska, Darya Melnyk, Manju Joshi, John F. Cipollo

DOI: 10.1128/JVI.01693-18



Prior to each annual flu season, health authorities recommend three or four virus strains for inclusion in the annual influenza vaccine: a Type A:H1N1, a Type A:H3N2, and one or two Type B viruses. Antigenic differences between strains are found in the glycosylation patterns of the major influenza antigen, hemagglutinin (HA). Here we examine the glycosylation patterns of seven reference antigens containing HA used in influenza vaccine potency testing. These reagents are supplied by the Center for Biologics Evaluation and Research (CBER) or the National Institute for Biological Standards and Control (NIBSC) for use in vaccine testing. Those produced in hen egg, Madin Darby Canine Kidney (MDCK), and insect (Sf9) expression systems were examined. They are closely related or identical to antigens used in commercial vaccine. Reference antigens studied were used in the 2014-2015 influenza season and included A/California/07/2009 H1N1, A/Texas/50/2012 H3N2 and B/Massachusetts/02/2012. Released glycan and HA specific glycopeptide glycosylation patterns were examined. Also examined was the sensitivity of the Single Radial Immunodiffusion Assay (SRID) potency test to differences in HA antigen glycosylation. The SRID assay was not sensitive to any HA antigen glycosylation status from any cell system based on deglycosylation studies as applied using standard assay procedures. Mapping of glycosites with their occupying glycan to functional regions, including antigenic sites, lectin interaction regions and fusion domains was performed and has implications for immune processing, immune response and antigenic shielding. Differences in glycosylation patterns, as dictated by cell system used in expression, may impact on these functions.



Here the glycosylation patterns of the 2014-2015 influenza vaccine season standard antigens A/California/07/2009 H1N1, A/Texas/50/2012 H3N2, and B/Massachusetts/02/2012 were revealed and sensitivity of the Single Radial Immunodiffusion Assay (SRID) potency test glycosylation was tested. Differences in hemagglutinin glycosylation site composition and heterogeneity seen in antigen produced in different cell substrates suggests differences in processing and downstream immune response. The SRID potency test used in vaccine release, is not sensitive to differences in glycosylation when applied under standard use conditions. This work reveals important differences in vaccine antigens and may point toward areas where improvements may be made concerning vaccine antigen preparation, immune processing and testing.

This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Keywords: Seasonal Influenza; H1N1pdm09; H3N2; Influenza B; Vaccines.