scholarly journals Does Pandemic A/H1N1 Virus Have the Potential To Become More Pathogenic?

mBio ◽  
2010 ◽  
Vol 1 (5) ◽  
Author(s):  
Natalia A. Ilyushina ◽  
Mariette F. Ducatez ◽  
Jerold E. Rehg ◽  
Bindumadhav M. Marathe ◽  
Henju Marjuki ◽  
...  
Keyword(s):  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Polymerase Activity ◽  
Acidic Protein ◽  
Progeny Virus ◽  
H1n1 Pandemic ◽  
Future Evolution ◽  
Pandemic Strain ◽  
Pandemic Virus ◽  
Pandemic Strains

ABSTRACT Epidemiologic observations that have been made in the context of the current pandemic influenza virus include a stable virulence phenotype and a lack of propensity to reassort with seasonal strains. In an attempt to determine whether either of these observations could change in the future, we coinfected differentiated human airway cells with seasonal oseltamivir-resistant A/New Jersey/15/07 and pandemic A/Tennessee/1-560/09 (H1N1) viruses in three ratios (10:90, 50:50, and 90:10) and examined the resulting progeny viruses after 10 sequential passages. When the pandemic virus was initially present at multiplicities of infection equal to or greater than those for the seasonal virus, only pandemic virus genotypes were detected. These adapted pandemic strains did, however, contain two nonsynonymous mutations (hemagglutinin K154Q and polymerase acidic protein L295P) that conferred a more virulent phenotype, both in cell cultures and in ferrets, than their parental strains. The polymerase acidic protein mutation increased polymerase activity at 37°C, and the hemagglutinin change affected binding of the virus to α2,6-sialyl receptors. When the seasonal A/H1N1 virus was initially present in excess, the dominant progeny virus was a reassortant containing the hemagglutinin gene from the seasonal strain and the remaining genes from the pandemic virus. Our study demonstrates that the emergence of an A/H1N1 pandemic strain of higher virulence is possible and that, despite their lack of detection thus far in humans, viable seasonal/pandemic virus reassortants can be generated. IMPORTANCE This report supplies a key piece of information for investigating future evolution scenarios of pandemic A/H1N1 influenza in the human population. We report that the emergence of an A/H1N1 pandemic strain of higher virulence is possible and that, despite their lack of detection thus far in humans, viable seasonal/pandemic virus reassortants can be generated.

scholarly journals The PB2-E627K Mutation Attenuates Viruses Containing the 2009 H1N1 Influenza Pandemic Polymerase

mBio ◽  
2010 ◽  
Vol 1 (1) ◽  
Author(s):  
Brett W. Jagger ◽  
Matthew J. Memoli ◽  
Zong-Mei Sheng ◽  
Li Qi ◽  
Rachel J. Hrabal ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Influenza Pandemic ◽  
Influenza Infection ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Pandemic Virus ◽  
2009 H1n1 ◽  
Animal Reservoirs

ABSTRACTThe swine-origin H1N1 influenza A virus emerged in early 2009 and caused the first influenza pandemic in 41 years. The virus has spread efficiently to both the Northern and the Southern Hemispheres and has been associated with over 16,000 deaths. Given the virus’s recent zoonotic origin, there is concern that the virus could acquire signature mutations associated with the enhanced pathogenicity of previous pandemic viruses or H5N1 viruses with pandemic potential. We tested the hypothesis that mutations in the polymerase PB2 gene at residues 627 and 701 would enhance virulence but found that influenza viruses containing these mutations in the context of the pandemic virus polymerase complex are attenuated in cell culture and mice.IMPORTANCEInfluenza A virus (IAV) evolution is characterized by host-specific lineages, and IAVs derived in whole or in part from animal reservoirs have caused pandemics in humans. Because IAVs are known to acquire host-adaptive genome mutations, and since the PB2 gene of the 2009 H1N1 virus is of recent avian derivation, there exists concern that the pathogenicity of the 2009 H1N1 influenza A pandemic virus could be potentiated by acquisition of the host-adaptive PB2-E627K or -D701N mutations, which have been shown to enhance the virulence of other influenza viruses. We present data from a mouse model of influenza infection showing that such mutations do not increase the virulence of viruses containing the 2009 H1N1 viral polymerase.

scholarly journals Seroprevalence of Pandemic 2009 (H1N1) Influenza A Virus among Schoolchildren and Their Parents in Tokyo, Japan

2011 ◽  
Vol 18 (5) ◽  
pp. 860-866 ◽  
Author(s):  
Kiyoko Iwatsuki-Horimoto ◽  
Taisuke Horimoto ◽  
Daisuke Tamura ◽  
Maki Kiso ◽  
Eiryo Kawakami ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Asymptomatic Infection ◽  
Pandemic H1n1 ◽  
Pandemic Virus ◽  
High Prevalence ◽  
2009 H1n1 ◽  
Insight Into

ABSTRACTSince its emergence, the 2009 pandemic H1N1 virus has spread rapidly throughout the world. Previously, we reported that most individuals born after 1920 do not have cross-reactive virus-neutralizing antibodies against pandemic (H1N1) 2009 virus, indicating that they were immunologically naïve to the pandemic virus prior to its emergence. This finding provided us with an excellent opportunity for a seroepidemiological investigation of the transmission mode of the pandemic virus in the community. To gain insight into its transmission within communities, we performed a serosurvey for pandemic virus infection with schoolchildren at an elementary school in Tokyo, Japan, and their parents. We observed a high prevalence of neutralizing antibodies to the pandemic virus in the children at this school, although the percentage of children positive for the neutralizing antibodies varied among classrooms. While a much lower prevalence was observed among parents, seropositivity of the parents correlated with that of their schoolchildren. Moreover, many adults appeared to have experienced asymptomatic infection with the pandemic virus. These data suggest that the pandemic virus was readily transmitted among schoolchildren in elementary schools and that it was also transmitted from schoolchildren to their parents.

scholarly journals Progression and Trends in Virus from Influenza A to COVID-19: An Overview of Recent Studies

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1145
Author(s):  
Hakimeh Baghaei Daemi ◽  
Muhammad Fakhar-e-Alam Kulyar ◽  
Xinlin He ◽  
Chengfei Li ◽  
Morteza Karimpour ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
World Health ◽  
H1n1 Pandemic ◽  
Global Pandemic ◽  
First Case ◽  
Influenza A H1n1 ◽  
The World ◽  
Novel Coronavirus ◽  
Health Organization

Influenza is a highly known contagious viral infection that has been responsible for the death of many people in history with pandemics. These pandemics have been occurring every 10 to 30 years in the last century. The most recent global pandemic prior to COVID-19 was the 2009 influenza A (H1N1) pandemic. A decade ago, the H1N1 virus caused 12,500 deaths in just 19 months globally. Now, again, the world has been challenged with another pandemic. Since December 2019, the first case of a novel coronavirus (COVID-19) infection was detected in Wuhan. This infection has risen rapidly throughout the world; even the World Health Organization (WHO) announced COVID-19 as a worldwide emergency to ensure human health and public safety. This review article aims to discuss important issues relating to COVID-19, including clinical, epidemiological, and pathological features of COVID-19 and recent progress in diagnosis and treatment approaches for the COVID-19 infection. We also highlight key similarities and differences between COVID-19 and influenza A to ensure the theoretical and practical details of COVID-19.

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

Vaccines ◽  
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.

scholarly journals Influenza A (H1N1) virus infection and TNF-308, IL6, and IL8 polymorphisms in Egyptian population: a case–control study

2019 ◽  
Vol 80 (1) ◽  
Author(s):  
Shaimaa Moustafa Elsayed ◽  
Omayma Mohamed Hassanein ◽  
Nagwa Hassan Ali Hassan
Keyword(s):  
Influenza A ◽  
Case Control Study ◽  
H1n1 Virus ◽  
Case Control ◽  
Severe Illness ◽  
Study Results ◽  
Influenza A H1n1 ◽  
Pandemic Strains ◽  
Study Participants ◽  
Control Study

Abstract Background The importance of influenza is increasing mainly because of the appearance of novel pandemic strains such as swine and avian. Each year, influenza has spread around the world causing about 250,000–500,000 deaths and more than 5 million cases of severe illness. The objective is as follows: evaluating the outcomes of patients with influenza A (H1N1) virus in relation to certain TNF-308, IL6, and IL8 polymorphisms and identifying the associated factors with the severe outcome. Subject and methods This is a case–control study. The cases were patients confirmed by real-time polymerase chain reaction (RT-PCR) to be influenza A (H1N1) virus infected. The controls were healthy individuals. Medical history and outcome of the disease was registered. In all study participants, polymorphisms of TNF rs1800629, IL6 rs18138879, and IL8 rs4073; odds ratio (OR); and the 95% confidence interval (95% CI) were calculated. Results Infection with influenza A (H1N1) virus was associated more with the following genotypes: TNF-308 AA (OR = 4.041; 95% CI = 1.215–13.4) and IL8 AA (OR = 3.273; 95% CI = 1.372–7.805). According to our study results, HCV (OR = 3.2, 95% CI 1.2–8.5), renal disease (OR = 3.4, 95% CI 0.9–13.6), cancer (OR = 3.1, 95% CI 0.3–31.1), TB (OR = 8.4, 95% CI 1.8–39.7), ICU (OR = 2.9, 95%1.2–7.1), and mortality (OR = 7.9, 95% CI 0.9–67.4) are considered as risk factors for influenza A (H1N1)-infected patients. Conclusions Our findings concluded that TNF-308 (AA) and IL8 (AA) polymorphisms may increase the susceptibility to be infected with H1N1influenza virus.

scholarly journals Subcutaneous Immunization with Baculovirus Surface-Displayed Hemagglutinin of Pandemic H1N1 Influenza A Virus Induces Protective Immunity in Mice

2011 ◽  
Vol 18 (9) ◽  
pp. 1582-1585 ◽  
Author(s):  
Mookkan Prabakaran ◽  
Tao Meng ◽  
Fang He ◽  
Tan YunRui ◽  
Jia Qiang ◽  
...  
Keyword(s):  
Virus Infection ◽  
Protective Immunity ◽  
Influenza A ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Influenza Virus Hemagglutinin ◽  
Inactive Form ◽  
2009 H1n1 ◽  
Subcutaneous Immunization ◽  
H1n1 Virus Infection

ABSTRACTThe protective immunity of baculovirus displaying influenza virus hemagglutinin (BacHA) against influenza 2009 H1N1 virus infection in a murine model was investigated. The results showed that mice vaccinated with live BacHA or an inactive form of adjuvanted BacHA had enhanced specific antibody responses and induced protective immunity against 2009 H1N1 virus infection, suggesting the potential of baculovirus as a live or inactivated vaccine.

scholarly journals Neuraminidase Activity and Resistance of 2009 Pandemic H1N1 Influenza Virus to Antiviral Activity in Bronchoalveolar Fluid

2016 ◽  
Vol 90 (9) ◽  
pp. 4637-4646 ◽  
Author(s):  
Kanyarat Ruangrung ◽  
Ornpreya Suptawiwat ◽  
Kittipong Maneechotesuwan ◽  
Chompunuch Boonarkart ◽  
Warunya Chakritbudsabong ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Antiviral Activity ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Surfactant Protein D ◽  
Pandemic H1n1 ◽  
Drug Resistant ◽  
Bronchoalveolar Fluid ◽  
Influenza Activity ◽  
Resistant Strains

ABSTRACTHuman bronchoalveolar fluid is known to have anti-influenza activity. It is believed to be a frontline innate defense against the virus. Several antiviral factors, including surfactant protein D, are believed to contribute to the activity. The 2009 pandemic H1N1 influenza virus was previously shown to be less sensitive to surfactant protein D. Nevertheless, whether different influenza virus strains have different sensitivities to the overall anti-influenza activity of human bronchoalveolar fluid was not known. We compared the sensitivities of 2009 pandemic H1N1, seasonal H1N1, and seasonal H3N2 influenza virus strains to inhibition by human bronchoalveolar lavage (BAL) fluid. The pandemic and seasonal H1N1 strains showed lower sensitivity to human BAL fluid than the H3N2 strains. The BAL fluid anti-influenza activity could be enhanced by oseltamivir, indicating that the viral neuraminidase (NA) activity could provide resistance to the antiviral defense. In accordance with this finding, the BAL fluid anti-influenza activity was found to be sensitive to sialidase. The oseltamivir resistance mutation H275Y rendered the pandemic H1N1 virus but not the seasonal H1N1 virus more sensitive to BAL fluid. Since only the seasonal H1N1 but not the pandemic H1N1 had compensatory mutations that allowed oseltamivir-resistant strains to maintain NA enzymatic activity and transmission fitness, the resistance to BAL fluid of the drug-resistant seasonal H1N1 virus might play a role in viral fitness.IMPORTANCEHuman airway secretion contains anti-influenza activity. Different influenza strains may vary in their susceptibilities to this antiviral activity. Here we show that the 2009 pandemic and seasonal H1N1 influenza viruses were less sensitive to human bronchoalveolar lavage (BAL) fluid than H3N2 seasonal influenza virus. The resistance to the pulmonary innate antiviral activity of the pandemic virus was determined by its neuraminidase (NA) gene, and it was shown that the NA inhibitor resistance mutation H275Y abolished this resistance of the pandemic H1N1 but not the seasonal H1N1 virus, which had compensatory mutations that maintained the fitness of drug-resistant strains. Therefore, the innate respiratory tract defense may be a barrier against NA inhibitor-resistant mutants, and evasion of this defense may play a role in the emergence and spread of drug-resistant strains.

scholarly journals Neurological complications after H1N1 influenza vaccination: magnetic resonance imaging findings

2014 ◽  
Vol 72 (7) ◽  
pp. 496-499 ◽  
Author(s):  
Ronaldo Lessa ◽  
Maurício Castillo ◽  
Renata Azevedo ◽  
Fernanda Azevedo ◽  
Hildo Azevedo
Keyword(s):  
Facial Palsy ◽  
H1n1 Virus ◽  
Altered Mental Status ◽  
H1n1 Influenza ◽  
Neurological Complications ◽  
Abrupt Onset ◽  
Resonance Imaging ◽  
Post Vaccination ◽  
Peripheral Facial Palsy ◽  
The Right

Objective: To report 4 different neurological complications of H1N1 virus vaccination. Method: Four patients (9, 16, 37 and 69 years of age) had neurological symptoms (intracranial hypertension, ataxia, left peripheral facial palsy of abrupt onset, altered mental status, myelitis) starting 4-15 days after H1N1 vaccination. MRI was obtained during the acute period. Results: One patient with high T2 signal in the cerebellum interpreted as acute cerebellitis; another, with left facial palsy, showed contrast enhancement within both internal auditory canals was present, however it was more important in the right side; one patient showed gyriform hyperintensities on FLAIR with sulcal effacement in the right fronto-parietal region; and the last one showed findings compatible with thoracic myelitis. Conclusion: H1N1 vaccination can result in important neurological complications probably secondary to post-vaccination inflammation. MRI detected abnormalities in all patients.

scholarly journals Profile of Brazilian scientific production on A/H1N1 pandemic influenza

2012 ◽  
Vol 17 (6) ◽  
pp. 1629-1634 ◽  
Author(s):  
Adriana Luchs
Keyword(s):  
Impact Factor ◽  
H1n1 Influenza ◽  
Scientific Production ◽  
Similar Amount ◽  
H1n1 Pandemic ◽  
Public Funds ◽  
The Impact ◽  
Journal Impact ◽  
Bibliometric Studies ◽  
Made In

In the last few years, bibliometric studies have proliferated, seeking to provide data on world research. This study analyzes the profile of the Brazilian scientific production in the A (H1N1) influenza field between 2009 and 2011. The research was conducted in MEDLINE, SciELO and LILACS databases, selecting papers in which the term "H1N1" and "Brazil" were defined as the main topics. The data were analyzed taking into consideration the Brazilian state and institution in which the articles were produced, the impact factor of the journal and the language. The research revealed 40 documents (27 from MEDLINE, 16 from SciELO and 24 from LILACS). The journal impact factor ranged from 0.0977 to 8.1230. A similar amount of articles were written in English and Portuguese and São Paulo was the most productive state in the country, with 95% of the Brazilian production originating from the Southern and Southeastern regions. Linguistic data indicate that previous efforts made in order to improve the scientific production of Brazilian researchers making their observations attain a broader scientific audience produced results. It is necessary to assess the scientific studies, especially those conducted with public funds, in order to ensure that the results will benefit society.

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