background: influenza viruses are a significant cause of morbidity and mortality. the influenza virus pandemics, 1918, 1977, and especially the most recent one, a/h1n1/2009, made evident the need for generating recombinant influenza h1n1 antigens which are essential to develop both basic and applied research programs. among influenza virus proteins, haemagglutinin (ha) is a major surface antige...

On August 2010, the World Health Organization declared the end to the 2009 A(H1N1) pandemic. However, influenza A(H1N1)pdm09 continues to circulate as a seasonal virus. Different viruses have predominated in different parts of the world. To date, influenza A(H1N1)pdm09 has demonstrated little antigenic drift, and its oseltamivir resistance has remained low. In some countries, a higher number of...

BACKGROUND & OBJECTIVES Most studies on the clinical presentation with influenza viruses have been conducted in outpatient or inpatient medical facilities with only a few studies in community settings. Clinical differences between influenza A (H1N1) pdm 09 and influenza B virus infections have importance for community-based public health surveillance. An active community surveillance at the tim...

BACKGROUND The World Health Organization and European Centre for Disease Prevention and Control have highlighted the importance of establishing systems to monitor severe influenza. Following the H1N1 (2009) influenza pandemic, a sentinel network of 23 Trusts, the UK Severe Influenza Surveillance System (USISS), was established to monitor hospitalisations due to confirmed seasonal influenza in E...

Introduction Renewed interest in the safety of administering egg-containing immunizations to egg allergic children and adults (EA) was prominent during the recent global pandemic of the H1N1 Influenza A virus in 2009-2010. The H1N1 Influenza A vaccine (H1N1), like the seasonal Trivalent Influenza Vaccine (TIV) is grown on embryonated chicken eggs, leading to concerns that residual contamination...

HIV-1-infected patients co-infected with A(H1N1)pdm09 surprisingly presented benign clinical outcome. The knowledge that HIV-1 changes the host homeostatic equilibrium, which may favor the patient resistance to some co-pathogens, prompted us to investigate whether HIV-1 infection could influence A(H1N1)pdm09 life cycle in vitro. We show here that exposure of A(H1N1)pdm09-infected epithelial cel...

BACKGROUND In April 2009, public health surveillance detected an increased number of influenza-like illnesses in Mexico City's hospitals. The etiological agent was subsequently determined to be a spread of a worldwide novel influenza A (H1N1) triple reassortant. The purpose of the present study was to demonstrate that molecular detection of pandemic influenza A (H1N1) 2009 strains is possible i...

OBJECTIVES During the 2009 influenza A H1N1 pandemic, it became difficult to differentiate viral infections from other conditions in patients admitted to the intensive care unit. We sought to evaluate the behavior and diagnostic utility of procalcitonin, C-reactive protein and four other molecules in patients with suspected 2009 Influenza A H1N1 infection. METHODS The serum levels of procalci...

OBJECTIVE To determine the effectiveness of an adjuvanted monovalent vaccine against pandemic influenza A/H1N1 among people with underlying chronic diseases. DESIGN Historical cohort study. SETTING Mandatory national reporting systems, 2 November 2009 to 31 January 2010, Denmark. PARTICIPANTS 388,069 people under 65 years of age with a diagnosis in the past five years of at least one unde...

In Denmark, both influenza A(H1N1)pdm09 and influenza B co-circulated in the 2015/16 season. We estimated the vaccine effectiveness (VE) of the trivalent influenza vaccine in patients 65 years and older using the test-negative case-control design. The adjusted VE against influenza A(H1N1)pdm09 was 35.0% (95% confidence interval (CI): 11.1-52.4) and against influenza B 4.1% (95% CI: -22.0 to 24....