scholarly journals Human Infection with a Triple‐Reassortant Swine Influenza A(H1N1) Virus Containing the Hemagglutinin and Neuraminidase Genes of Seasonal Influenza Virus

2010 ◽  
Vol 201 (8) ◽  
pp. 1178-1182 ◽  
Author(s):  
Nathalie Bastien ◽  
Nick A. Antonishyn ◽  
Ken Brandt ◽  
Christine E. Wong ◽  
Khami Chokani ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Human Infection ◽  
Influenza A H1n1

scholarly journals Contemporary Seasonal Influenza A (H1N1) Virus Infection Primes for a More Robust Response To Split Inactivated Pandemic Influenza A (H1N1) Virus Vaccination in Ferrets

2010 ◽  
Vol 17 (12) ◽  
pp. 1998-2006 ◽  
Author(s):  
Ali H. Ellebedy ◽  
Thomas P. Fabrizio ◽  
Ghazi Kayali ◽  
Thomas H. Oguin ◽  
Scott A. Brown ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Inactivated Vaccine ◽  
H1n1 Influenza Virus ◽  
Influenza A H1n1

ABSTRACT Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to achieve human-to-human transmission. In April 2009, cases of a novel H1N1 influenza virus in children in the southwestern United States were reported. It was retrospectively shown that these cases represented the spread of this virus from an ongoing outbreak in Mexico. The emergence of the pandemic led to a number of national vaccination programs. Surprisingly, early human clinical trial data have shown that a single dose of nonadjuvanted pandemic influenza A (H1N1) 2009 monovalent inactivated vaccine (pMIV) has led to a seroprotective response in a majority of individuals, despite earlier studies showing a lack of cross-reactivity between seasonal and pandemic H1N1 viruses. Here we show that previous exposure to a contemporary seasonal H1N1 influenza virus and to a lesser degree a seasonal influenza virus trivalent inactivated vaccine is able to prime for a higher antibody response after a subsequent dose of pMIV in ferrets. The more protective response was partially dependent on the presence of CD8+ cells. Two doses of pMIV were also able to induce a detectable antibody response that provided protection from subsequent challenge. These data show that previous infection with seasonal H1N1 influenza viruses likely explains the requirement for only a single dose of pMIV in adults and that vaccination campaigns with the current pandemic influenza vaccines should reduce viral burden and disease severity in humans.

scholarly journals Pathogenesis of Pandemic Influenza A (H1N1) and Triple-Reassortant Swine Influenza A (H1) Viruses in Mice

2010 ◽  
Vol 84 (9) ◽  
pp. 4194-4203 ◽  
Author(s):  
Jessica A. Belser ◽  
Debra A. Wadford ◽  
Claudia Pappas ◽  
Kortney M. Gustin ◽  
Taronna R. Maines ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
The United States ◽  
Chemokine Production ◽  
Highly Pathogenic ◽  
Influenza A H1n1 ◽  
2009 H1n1

ABSTRACT The pandemic H1N1 virus of 2009 (2009 H1N1) continues to cause illness worldwide, primarily in younger age groups. To better understand the pathogenesis of these viruses in mammals, we used a mouse model to evaluate the relative virulence of selected 2009 H1N1 viruses and compared them to a representative human triple-reassortant swine influenza virus that has circulated in pigs in the United States for over a decade preceding the current pandemic. Additional comparisons were made with the reconstructed 1918 virus, a 1976 H1N1 swine influenza virus, and a highly pathogenic H5N1 virus. Mice were inoculated intranasally with each virus and monitored for morbidity, mortality, viral replication, hemostatic parameters, cytokine production, and lung histology. All 2009 H1N1 viruses replicated efficiently in the lungs of mice and possessed a high degree of infectivity but did not cause lethal disease or exhibit extrapulmonary virus spread. Transient weight loss, lymphopenia, and proinflammatory cytokine and chemokine production were present following 2009 H1N1 virus infection, but these levels were generally muted compared with a triple-reassortant swine virus and the 1918 virus. 2009 H1N1 viruses isolated from fatal cases did not demonstrate enhanced virulence in this model compared with isolates from mild human cases. Histologically, infection with the 2009 viruses resulted in lesions in the lung varying from mild to moderate bronchiolitis with occasional necrosis of bronchiolar epithelium and mild to moderate peribronchiolar alveolitis. Taken together, these studies demonstrate that the 2009 H1N1 viruses exhibited mild to moderate virulence in mice compared with highly pathogenic viruses.

scholarly journals Virological and serological study of human infection with swine influenza A H1N1 virus in China

Virology ◽  
2013 ◽  
Vol 446 (1-2) ◽  
pp. 49-55 ◽  
Author(s):  
Rongqiang Zu ◽  
Libo Dong ◽  
Xian Qi ◽  
Dayan Wang ◽  
Shumei Zou ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Human Infection ◽  
Serological Study ◽  
Influenza A H1n1

scholarly journals High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland

2010 ◽  
Vol 15 (5) ◽  
Author(s):  
N Ikonen ◽  
M Strengell ◽  
L Kinnunen ◽  
P Österlund ◽  
J Pirhonen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
The Elderly ◽  
Influenza Viruses ◽  
Spanish Influenza ◽  
Pandemic Virus ◽  
Influenza A H1n1

Since May 2009, the pandemic influenza A(H1N1) virus has been spreading throughout the world. Epidemiological data indicate that the elderly are underrepresented among the ill individuals. Approximately 1,000 serum specimens collected in Finland in 2004 and 2005 from individuals born between 1909 and 2005, were analysed by haemagglutination-inhibition test for the presence of antibodies against the 2009 pandemic influenza A(H1N1) and recently circulating seasonal influenza A viruses. Ninety-six per cent of individuals born between 1909 and 1919 had antibodies against the 2009 pandemic influenza virus, while in age groups born between 1920 and 1944, the prevalence varied from 77% to 14%. Most individuals born after 1944 lacked antibodies to the pandemic virus. In sequence comparisons the haemagglutinin (HA) gene of the 2009 pandemic influenza A(H1N1) virus was closely related to that of the Spanish influenza and 1976 swine influenza viruses. Based on the three-dimensional structure of the HA molecule, the antigenic epitopes of the pandemic virus HA are more closely related to those of the Spanish influenza HA than to those of recent seasonal influenza A(H1N1) viruses. Among the elderly, cross-reactive antibodies against the 2009 pandemic influenza virus, which likely originate from infections caused by the Spanish influenza virus and its immediate descendants, may provide protective immunity against the present pandemic virus.

scholarly journals An influenza A (H1N1) virus, closely related to swine influenza virus, responsible for a fatal case of human influenza.

1994 ◽  
Vol 68 (4) ◽  
pp. 2051-2058 ◽  
Author(s):  
D E Wentworth ◽  
B L Thompson ◽  
X Xu ◽  
H L Regnery ◽  
A J Cooley ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Fatal Case ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Human Influenza ◽  
Influenza A H1n1

scholarly journals Cross-protective immunity against influenza pH1N1 2009 viruses induced by seasonal influenza A (H3N2) virus is mediated by virus-specific T-cells

2011 ◽  
Vol 92 (10) ◽  
pp. 2339-2349 ◽  
Author(s):  
Marine L. B. Hillaire ◽  
Stella E. van Trierum ◽  
Joost H. C. M. Kreijtz ◽  
Rogier Bodewes ◽  
Martina M. Geelhoed-Mieras ◽  
...  
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
Virus Infection ◽  
Protective Immunity ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
H3n2 Virus ◽  
Influenza A H1n1 ◽  
H1n1 Virus Infection

Influenza A (H1N1) viruses of swine origin were introduced into the human population in 2009 and caused a pandemic. The disease burden in the elderly was relatively low, which was attributed to the presence of cross-reacting serum antibodies in this age group, which were raised against seasonal influenza A (H1N1) viruses that circulated before 1957. It has also been described how infection with heterosubtypic influenza viruses can induce some degree of protection against infection by a novel strain of influenza virus. Here, we assess the extent of protective immunity against infection with the 2009 influenza A (H1N1) pandemic influenza virus that is afforded by infection with a seasonal influenza A (H3N2) virus in mice. Mice that experienced a primary A (H3N2) influenza virus infection displayed reduced weight loss after challenge infection and cleared the 2009 influenza A (H1N1) virus infection more rapidly. To elucidate the correlates of protection of this heterosubtypic immunity to pandemic H1N1 virus infection, adoptive transfer experiments were carried out by using selected post-infection lymphocyte populations. Virus-specific CD8+ T-cells in concert with CD4+ T-cells were responsible for the observed protection. These findings may not only provide an explanation for epidemiological differences in the incidence of severe pandemic H1N1 infections, they also indicate that the induction of cross-reactive virus-specific CD8+ and CD4+ T-cell responses may be a suitable approach for the development of universal influenza vaccines.

Human infection by a swine influenza A (H1N1) virus in Switzerland

2003 ◽  
Vol 148 (4) ◽  
pp. 793-802 ◽  
Author(s):  
V. Gregory ◽  
M. Bennett ◽  
Y. Thomas ◽  
L. Kaiser ◽  
W. Wunderli ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Human Infection ◽  
Influenza A H1n1

scholarly journals Human Infection with Eurasian Avian-Like Swine Influenza A(H1N1) Virus, the Netherlands, September 2019

2021 ◽  
Vol 27 (3) ◽  
pp. 939-943
Author(s):  
Anna Parys ◽  
Elien Vandoorn ◽  
Jacqueline King ◽  
Annika Graaf ◽  
Anne Pohlmann ◽  
...  
Keyword(s):  
The Netherlands ◽  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Human Infection ◽  
Influenza A H1n1
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