Development and Characterization of Recombinant Vesicular Stomatitis Virus (rVSV)-based Bivalent Vaccine Against COVID-19 Delta Variant and Influenza Virus

COVID-19 and influenza are both highly contagious respiratory diseases with a wide range of severe symptoms and cause great disease burdens globally. It has become very urgent and important to develop a bivalent vaccine that is able to target these two infectious diseases simultaneously. In this study, we generated three attenuated replicating recombinant VSV (rVSV) vaccine candidates. These rVSV-based vaccines co-express SARS-CoV-2 Delta variant spike protein (SP) or the receptor binding domain (RBD) and four copies of the highly conserved M2 ectodomain (M2e) of influenza A fused with the Ebola glycoprotein DC-targeting/activation domain. Animal studies have shown that immunization with these bivalent rVSV vaccines induced efficient but variable levels of humoral and cell-mediated immune responses against both SARS-CoV-2 and influenza M2e protein. Significantly, our vaccine candidates induced production of high levels of neutralizing antibodies that protected cells against SARS-CoV-2 Delta and other SP-pseudovirus infections in culture. Furthermore, vaccination with the bivalent VSV vaccine via either intramuscular or intranasal route efficiently protected mice from the lethal challenge of H1N1 and H3N2 influenza viruses and significantly reduced viral load in the lungs. These studies provide convincing evidence for the high efficacy of this bivalent vaccine to prevent influenza replication and initiate robust immune responses against SARS-CoV-2 Delta variants. Further investigation of its efficacy to protect against SARS-CoV-2 Delta variants will provide substantial evidence for new avenues to control two contagious respiratory infections, COVID-19 and influenza.

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Influenza viral particles harboring the SARS-CoV-2 spike RBD as a combination respiratory disease vaccine

10.1101/2021.04.30.441968 ◽

2021 ◽

Author(s):

Ryan R Chaparian ◽

Alfred T Harding ◽

Kristina Riebe ◽

Amelia Karlsson ◽

Gregory D Sempowski ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Influenza A ◽

Seasonal Influenza ◽

Cost Effective ◽

Influenza Viruses ◽

Combination Vaccine ◽

Lethal Challenge ◽

Fda Approval ◽

Viral Particles ◽

Production And Distribution

Vaccines targeting SARS-CoV-2 have gained emergency FDA approval, however the breadth against emerging variants and the longevity of protection remains unknown. Post-immunization boosting may be required, perhaps on an annual basis if the virus becomes an endemic pathogen. Seasonal influenza virus vaccines are already developed every year, an undertaking made possible by a robust global vaccine production and distribution infrastructure. To create a seasonal combination vaccine targeting influenza viruses and SARS-CoV-2 that is also amenable to frequent reformulation, we have developed a recombinant influenza A virus (IAV) genetic platform that reprograms the virus to package an immunogenic domain of the SARS-CoV-2 spike (S) protein onto IAV particles. Vaccination with this combination vaccine elicits neutralizing antibodies and provides protection from lethal challenge with both pathogens. This technology may allow for leveraging of established influenza vaccine infrastructure to generate a cost-effective and scalable seasonal vaccine solution for both influenza and coronaviruses.

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Next generation methodology for updating HA vaccines against emerging human seasonal influenza A(H3N2) viruses

Scientific Reports ◽

10.1038/s41598-020-79590-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

James D. Allen ◽

Ted M. Ross

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Viruses ◽

Next Generation ◽

Virus Infections ◽

Wild Type ◽

Influenza Hemagglutinin ◽

H3n2 Influenza

AbstractWhile vaccines remain the best tool for preventing influenza virus infections, they have demonstrated low to moderate effectiveness in recent years. Seasonal influenza vaccines typically consist of wild-type influenza A and B viruses that are limited in their ability to elicit protective immune responses against co-circulating influenza virus variant strains. Improved influenza virus vaccines need to elicit protective immune responses against multiple influenza virus drift variants within each season. Broadly reactive vaccine candidates potentially provide a solution to this problem, but their efficacy may begin to wane as influenza viruses naturally mutate through processes that mediates drift. Thus, it is necessary to develop a method that commercial vaccine manufacturers can use to update broadly reactive vaccine antigens to better protect against future and currently circulating viral variants. Building upon the COBRA technology, nine next-generation H3N2 influenza hemagglutinin (HA) vaccines were designed using a next generation algorithm and design methodology. These next-generation broadly reactive COBRA H3 HA vaccines were superior to wild-type HA vaccines at eliciting antibodies with high HAI activity against a panel of historical and co-circulating H3N2 influenza viruses isolated over the last 15 years, as well as the ability to neutralize future emerging H3N2 isolates.

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Immune Responses Elicited by Live Attenuated Influenza Vaccines as Correlates of Universal Protection against Influenza Viruses

Vaccines ◽

10.3390/vaccines9040353 ◽

2021 ◽

Vol 9 (4) ◽

pp. 353

Author(s):

Yo Han Jang ◽

Baik L. Seong

Keyword(s):

Immune Responses ◽

Neutralizing Antibodies ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Influenza Vaccines ◽

Immune Correlates ◽

Protection Efficacy ◽

Public Health Challenge ◽

Efficient Protection ◽

Universal Influenza Vaccine

Influenza virus infection remains a major public health challenge, causing significant morbidity and mortality by annual epidemics and intermittent pandemics. Although current seasonal influenza vaccines provide efficient protection, antigenic changes of the viruses often significantly compromise the protection efficacy of vaccines, rendering most populations vulnerable to the viral infection. Considerable efforts have been made to develop a universal influenza vaccine (UIV) able to confer long-lasting and broad protection. Recent studies have characterized multiple immune correlates required for providing broad protection against influenza viruses, including neutralizing antibodies, non-neutralizing antibodies, antibody effector functions, T cell responses, and mucosal immunity. To induce broadly protective immune responses by vaccination, various strategies using live attenuated influenza vaccines (LAIVs) and novel vaccine platforms are under investigation. Despite superior cross-protection ability, very little attention has been paid to LAIVs for the development of UIV. This review focuses on immune responses induced by LAIVs, with special emphasis placed on the breadth and the potency of individual immune correlates. The promising prospect of LAIVs to serve as an attractive and reliable vaccine platforms for a UIV is also discussed. Several important issues that should be addressed with respect to the use of LAIVs as UIV are also reviewed.

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Influenza A and B viruses in the population of Vojvodina, Serbia

Archives of Biological Sciences ◽

10.2298/abs1401043r ◽

2014 ◽

Vol 66 (1) ◽

pp. 43-50 ◽

Cited By ~ 2

Author(s):

J. Radovanov ◽

V. Milosevic ◽

I. Hrnjakovic ◽

V. Petrovic ◽

M. Ristic ◽

...

Keyword(s):

Influenza A ◽

Respiratory Infections ◽

Influenza Viruses ◽

Influenza B Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Influenza A Viruses ◽

B Virus ◽

Life Threatening ◽

Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

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Broadly Reactive H2 Hemagglutinin Vaccines Elicit Cross-Reactive Antibodies in Ferrets Preimmune to Seasonal Influenza A Viruses

mSphere ◽

10.1128/msphere.00052-21 ◽

2021 ◽

Vol 6 (2) ◽

Author(s):

Z. Beau Reneer ◽

Amanda L. Skarlupka ◽

Parker J. Jamieson ◽

Ted M. Ross

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Recombinant Proteins ◽

Human Population ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Viruses ◽

Wild Type ◽

Influenza A Viruses ◽

Global Pandemic

ABSTRACT Influenza vaccines have traditionally been tested in naive mice and ferrets. However, humans are first exposed to influenza viruses within the first few years of their lives. Therefore, there is a pressing need to test influenza virus vaccines in animal models that have been previously exposed to influenza viruses before being vaccinated. In this study, previously described H2 computationally optimized broadly reactive antigen (COBRA) hemagglutinin (HA) vaccines (Z1 and Z5) were tested in influenza virus “preimmune” ferret models. Ferrets were infected with historical, seasonal influenza viruses to establish preimmunity. These preimmune ferrets were then vaccinated with either COBRA H2 HA recombinant proteins or wild-type H2 HA recombinant proteins in a prime-boost regimen. A set of naive preimmune or nonpreimmune ferrets were also vaccinated to control for the effects of the multiple different preimmunities. All of the ferrets were then challenged with a swine H2N3 influenza virus. Ferrets with preexisting immune responses influenced recombinant H2 HA-elicited antibodies following vaccination, as measured by hemagglutination inhibition (HAI) and classical neutralization assays. Having both H3N2 and H1N1 immunological memory regardless of the order of exposure significantly decreased viral nasal wash titers and completely protected all ferrets from both morbidity and mortality, including the mock-vaccinated ferrets in the group. While the vast majority of the preimmune ferrets were protected from both morbidity and mortality across all of the different preimmunities, the Z1 COBRA HA-vaccinated ferrets had significantly higher antibody titers and recognized the highest number of H2 influenza viruses in a classical neutralization assay compared to the other H2 HA vaccines. IMPORTANCE H1N1 and H3N2 influenza viruses have cocirculated in the human population since 1977. Nearly every human alive today has antibodies and memory B and T cells against these two subtypes of influenza viruses. H2N2 influenza viruses caused the 1957 global pandemic and people born after 1968 have never been exposed to H2 influenza viruses. It is quite likely that a future H2 influenza virus could transmit within the human population and start a new global pandemic, since the majority of people alive today are immunologically naive to viruses of this subtype. Therefore, an effective vaccine for H2 influenza viruses should be tested in an animal model with previous exposure to influenza viruses that have circulated in humans. Ferrets were infected with historical influenza A viruses to more accurately mimic the immune responses in people who have preexisting immune responses to seasonal influenza viruses. In this study, preimmune ferrets were vaccinated with wild-type (WT) and COBRA H2 recombinant HA proteins in order to examine the effects that preexisting immunity to seasonal human influenza viruses have on the elicitation of broadly cross-reactive antibodies from heterologous vaccination.

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A Host-Restricted Self-Attenuated Influenza Virus Provides Broad Pan-Influenza A Protection in a Mouse Model

Frontiers in Immunology ◽

10.3389/fimmu.2021.779223 ◽

2021 ◽

Vol 12 ◽

Author(s):

Minjin Kim ◽

Yucheol Cheong ◽

Jinhee Lee ◽

Jongkwan Lim ◽

Sanguine Byun ◽

...

Keyword(s):

Influenza Virus ◽

Mouse Model ◽

Neutralizing Antibodies ◽

Influenza A ◽

Protective Efficacy ◽

Influenza Viruses ◽

Cross Protection ◽

Infection Model ◽

Wild Type ◽

Group 1

Influenza virus infections can cause a broad range of symptoms, form mild respiratory problems to severe and fatal complications. While influenza virus poses a global health threat, the frequent antigenic change often significantly compromises the protective efficacy of seasonal vaccines, further increasing the vulnerability to viral infection. Therefore, it is in great need to employ strategies for the development of universal influenza vaccines (UIVs) which can elicit broad protection against diverse influenza viruses. Using a mouse infection model, we examined the breadth of protection of the caspase-triggered live attenuated influenza vaccine (ctLAIV), which was self-attenuated by the host caspase-dependent cleavage of internal viral proteins. A single vaccination in mice induced a broad reactive antibody response against four different influenza viruses, H1 and rH5 (HA group 1) and H3 and rH7 subtypes (HA group 2). Notably, despite the lack of detectable neutralizing antibodies, the vaccination provided heterosubtypic protection against the lethal challenge with the viruses. Sterile protection was confirmed by the complete absence of viral titers in the lungs and nasal turbinates after the challenge. Antibody-dependent cellular cytotoxicity (ADCC) activities of non-neutralizing antibodies contributed to cross-protection. The cross-protection remained robust even after in vivo depletion of T cells or NK cells, reflecting the strength and breadth of the antibody-dependent effector function. The robust mucosal secretion of sIgA reflects an additional level of cross-protection. Our data show that the host-restricted designer vaccine serves an option for developing a UIV, providing pan-influenza A protection against both group 1 and 2 influenza viruses. The present results of potency and breadth of protection from wild type and reassortant viruses addressed in the mouse model by single immunization merits further confirmation and validation, preferably in clinically relevant ferret models with wild type challenges.

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Epidemiology of Respiratory Pathogens among Elderly Nursing Home Residents with Acute Respiratory Infections in Corsica, France, 2013–2017

BioMed Research International ◽

10.1155/2017/1423718 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Shirley Masse ◽

Lisandru Capai ◽

Alessandra Falchi

Keyword(s):

Nursing Home ◽

Influenza A ◽

Respiratory Infections ◽

Nursing Home Residents ◽

Respiratory Viruses ◽

Sudden Onset ◽

Influenza Viruses ◽

Influenza B ◽

Acute Respiratory Infections ◽

Respiratory Pathogens

Background. The current study aims to describe the demographical and clinical characteristics of elderly nursing home (NH) residents with acute respiratory infections (ARIs) during four winter seasons (2013/2014–2016/2017), as well as the microbiological etiology of these infections. Methods. Seventeen NHs with at least one ARI resident in Corsica, France, were included. An ARI resident was defined as a resident developing a sudden onset of any constitutional symptoms in addition to any respiratory signs. Nasopharyngeal swabs from ARI residents were screened for the presence of 21 respiratory agents, including seasonal influenza viruses. Results. Of the 107 ARI residents enrolled from NHs, 61 (57%) were positive for at least one of the 21 respiratory pathogens. Forty-one (38.3%) of the 107 ARI residents had influenza: 38 (92%) were positive for influenza A (100% A(H3N2)) and three (8%) for influenza B/Victoria. Axillary fever (≥38°C) was significantly more common among patients infected with influenza A(H3N2). Conclusion. The circulation of seasonal respiratory viruses other than influenza A(H3N2) seems to be sporadic among elderly NH residents. Investigating the circulation of respiratory viruses in nonwinter seasons seems to be important in order to understand better the dynamic of their year-round circulation in NHs.

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Evaluation of Live Attenuated Influenza A Virus H6 Vaccines in Mice and Ferrets

Journal of Virology ◽

10.1128/jvi.01775-08 ◽

2008 ◽

Vol 83 (1) ◽

pp. 65-72 ◽

Cited By ~ 45

Author(s):

Zhongying Chen ◽

Celia Santos ◽

Amy Aspelund ◽

Laura Gillim-Ross ◽

Hong Jin ◽

...

Keyword(s):

Influenza A Virus ◽

Neutralizing Antibodies ◽

Influenza A ◽

Serum Antibody ◽

Cross Reactivity ◽

Phenotypic Properties ◽

Vaccine Candidates ◽

Virus Challenge ◽

Avian Influenza A Virus ◽

Internal Gene

ABSTRACT Avian influenza A virus A/teal/HK/W312/97 (H6N1) possesses seven gene segments that are highly homologous to those of highly pathogenic human influenza H5N1 viruses, suggesting that a W312-like H6N1 virus might have been involved in the generation of the A/HK/97 H5N1 viruses. The continuous circulation and reassortment of influenza H6 subtype viruses in birds highlight the need to develop an H6 vaccine to prevent potential influenza pandemics caused by the H6 viruses. Based on the serum antibody cross-reactivity data obtained from 14 different H6 viruses from Eurasian and North American lineages, A/duck/HK/182/77, A/teal/HK/W312/97, and A/mallard/Alberta/89/85 were selected to produce live attenuated H6 candidate vaccines. Each of the H6 vaccine strains is a 6:2 reassortant ca virus containing HA and NA gene segments from an H6 virus and the six internal gene segments from cold-adapted A/Ann Arbor/6/60 (AA ca), the master donor virus that is used to make live attenuated influenza virus FluMist (intranasal) vaccine. All three H6 vaccine candidates exhibited phenotypic properties of temperature sensitivity (ts), ca, and attenuation (att) conferred by the internal gene segments from AA ca. Intranasal administration of a single dose of the three H6 ca vaccine viruses induced neutralizing antibodies in mice and ferrets and fully protected mice and ferrets from homologous wild-type (wt) virus challenge. Among the three H6 vaccine candidates, the A/teal/HK/W312/97 ca virus provided the broadest cross-protection against challenge with three antigenically distinct H6 wt viruses. These data support the rationale for further evaluating the A/teal/HK/W312/97 ca vaccine in humans.

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Eco-Epidemiological Evidence of the Transmission of Avian and Human Influenza A Viruses in Wild Pigs in Campeche, Mexico

Viruses ◽

10.3390/v12050528 ◽

2020 ◽

Vol 12 (5) ◽

pp. 528

Author(s):

Brenda Aline Maya-Badillo ◽

Rafael Ojeda-Flores ◽

Andrea Chaves ◽

Saul Reveles-Félix ◽

Guillermo Orta-Pineda ◽

...

Keyword(s):

Influenza A ◽

Influenza Viruses ◽

Influenza A Viruses ◽

Serum Samples ◽

Fragmented Habitats ◽

Wild Pigs ◽

Wide Range ◽

Influenza Transmission ◽

Human Viruses ◽

Positive Results

Influenza, a zoonosis caused by various influenza A virus subtypes, affects a wide range of species, including humans. Pig cells express both sialyl-α-2,3-Gal and sialyl-α-2,6-Gal receptors, which make them susceptible to infection by avian and human viruses, respectively. To date, it is not known whether wild pigs in Mexico are affected by influenza virus subtypes, nor whether this would make them a potential risk of influenza transmission to humans. In this work, 61 hogs from two municipalities in Campeche, Mexico, were sampled. Hemagglutination inhibition assays were performed in 61 serum samples, and positive results were found for human H1N1 (11.47%), swine H1N1 (8.19%), and avian H5N2 (1.63%) virus variants. qRT-PCR assays were performed on the nasal swab, tracheal, and lung samples, and 19.67% of all hogs were positive to these assays. An avian H5N2 virus, first reported in 1994, was identified by sequencing. Our results demonstrate that wild pigs are participating in the exposure, transmission, maintenance, and possible diversification of influenza viruses in fragmented habitats, highlighting the synanthropic behavior of this species, which has been poorly studied in Mexico.

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In Vitro Antiviral Activity of Favipiravir (T-705) against Drug-Resistant Influenza and 2009 A(H1N1) Viruses

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01739-09 ◽

2010 ◽

Vol 54 (6) ◽

pp. 2517-2524 ◽

Cited By ~ 82

Author(s):

Katrina Sleeman ◽

Vasiliy P. Mishin ◽

Varough M. Deyde ◽

Yousuke Furuta ◽

Alexander I. Klimov ◽

...

Keyword(s):

Influenza A ◽

Seasonal Influenza ◽

Mdck Cells ◽

Antiviral Effect ◽

Plaque Formation ◽

Influenza Viruses ◽

New Drugs ◽

Yield Reduction ◽

Wide Range

ABSTRACT Favipiravir (T-705) has previously been shown to have a potent antiviral effect against influenza virus and some other RNA viruses in both cell culture and in animal models. Currently, favipiravir is undergoing clinical evaluation for the treatment of influenza A and B virus infections. In this study, favipiravir was evaluated in vitro for its ability to inhibit the replication of a representative panel of seasonal influenza viruses, the 2009 A(H1N1) strains, and animal viruses with pandemic (pdm) potential (swine triple reassortants, H2N2, H4N2, avian H7N2, and avian H5N1), including viruses which are resistant to the currently licensed anti-influenza drugs. All viruses were tested in a plaque reduction assay with MDCK cells, and a subset was also tested in both yield reduction and focus inhibition (FI) assays. For the majority of viruses tested, favipiravir significantly inhibited plaque formation at 3.2 μM (0.5 μg/ml) (50% effective concentrations [EC50s] of 0.19 to 22.48 μM and 0.03 to 3.53 μg/ml), and for all viruses, with the exception of a single dually resistant 2009 A(H1N1) virus, complete inhibition of plaque formation was seen at 3.2 μM (0.5 μg/ml). Due to the 2009 pandemic and increased drug resistance in circulating seasonal influenza viruses, there is an urgent need for new drugs which target influenza. This study demonstrates that favipiravir inhibits in vitro replication of a wide range of influenza viruses, including those resistant to currently available drugs.

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