Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico

Introduction: On April 2009, the Mexican Ministry of Health received notification of cases of severe pneumonia mostly affecting young healthy people; this was the beginning of the first influenza pandemic of the 21st century. The nature of the immune response to the influenza A(H1N1)2009 pandemic strain in Mexico at the beginning of the pandemic outbreak has not been completely defined. We describe the serological response to the 2009 pandemic influenza virus in paediatric patients with influenza-like illness, their household contacts (HHCs), and exposed health-care workers (HCWs) at the beginning of the pandemic outbreak in Mexico City. Methodology: thirty pre-epidemic and 129 epidemic samples were collected and serum antibodies were measured against A(H1N1)2009 pandemic virus and two non-pandemic swine influenza viruses by an haemagglutination inhibition assay . Results: 91% (29/32) of the convalescence samples from confirmed patients had an antibody titre ≥ 10 (GMT 25), 63% (41/65) of the HHCs (GMT 12), 41% of HCWs (GMT 6) and 13% (4/30) of pre-epidemic samples (GMT 6) for the pandemic influenza virus. Of the 32 confirmed cases, 60% had an antibody titre ≥ 40 for the pandemic strain, 53% for the A/swine/Iowa(H1N1) virus (GMT 62) and 43% for the A/swine/Texas(H3N2) virus (GMT 66). Conclusion: The antibody response to 2009 pandemic influenza virus was widespread in convalescence samples from patients with confirmed pandemic influenza infection but the GMT was below the protective titre. There was no evidence that antibodies to the swine influenza viruses had cross-protective effect against the 2009 pandemic influenza virus.

Download Full-text

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

Clinical and Vaccine Immunology ◽

10.1128/cvi.00247-10 ◽

2010 ◽

Vol 17 (12) ◽

pp. 1998-2006 ◽

Cited By ~ 11

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.

Download Full-text

Isolation of H3N2 Swine Influenza Virus in South Korea

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870301500107 ◽

2003 ◽

Vol 15 (1) ◽

pp. 30-34 ◽

Cited By ~ 22

Author(s):

Dae S. Song ◽

Jae Y. Lee ◽

Jin S. Oh ◽

Kwang S. Lyoo ◽

Kyung J. Yoon ◽

...

Keyword(s):

Influenza Virus ◽

South Korea ◽

Respiratory Disease ◽

Swine Influenza Virus ◽

Swine Influenza ◽

Influenza Viruses ◽

H3n2 Virus ◽

Pcr Products ◽

Swine Population ◽

Swine Herds

Swine influenza is a significant respiratory disease causing occasional reproductive problems in nïve swine herds. Although different subtypes of swine influenza virus (SIV) have been implicated in clinical outbreaks of swine influenza in Asian countries, no virus isolation has been made to identify SIV of subtypes other than the H1N1 subtype in the Korean swine population. In December 1998, an outbreak of acute respiratory disease was identified in a commercial swine farm located in the Kyunggi province of South Korea. A causative agent, which agglutinated rooster red blood cells, was detected from the lungs of 3 piglets from the index herd and was determined to be type A influenza virus using a commercial influenza virus typing kit. Hemagglutination activity (HA) of the isolates was completely inhibited by a swine antiserum against a recent US H3N2 SIV isolate (A/Sw/IA/41305/1998) but not by H1N1 swine antiserum (A/Sw/IA/1979). Reverse transcription–polymerase chain reaction (RT-PCR) revealed all 3 isolates were H3 SIV subtypes. Sequence analysis of hemagglutinin gene PCR products supported the belief that the Korean H3 SIV isolates were genetically similar to the known mammalian H3 influenza viruses. This is the first report on a clinical outbreak of swine influenza caused by the H3N2 virus in Korea.

Download Full-text

KONFIRMASI FLU BABI A/H1N1 MENGGUNAKAN PCR

INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY ◽

10.24293/ijcpml.v16i2.979 ◽

2018 ◽

Vol 16 (2) ◽

pp. 93

Author(s):

A.A. Wiradewi Lestari ◽

I.A. Putri Wirawati ◽

Tjok Gde Oka

Keyword(s):

Influenza Virus ◽

Sore Throat ◽

Influenza A ◽

Swine Influenza ◽

Influenza Viruses ◽

Influenza A H1n1 ◽

Nasal Swabs ◽

2009 H1n1 ◽

Pcr Test

Swine Influenza (2009 H1N1) is a new influenza virus causing illness in people. This new virus was first detected in the United Statespeople, April 2009. This virus probably spread the same way worldwide from person-to-person much as the regular spreading of commonseasonal influenza viruses. A 13 years old male entered the hospital with fever, cough and sore throat. Before he was hospitalized, hehad travelled to Batam for four (4) days. A PCR test from throat and nasal swabs were taken, and found positive for influenza A andswine H1 (as confirmed case for swine influenza A/H1N1). After taking oseltamivir for 5 days and the second PCR test negative, thepatient is released from the hospital.

Download Full-text

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

Eurosurveillance ◽

10.2807/ese.15.05.19478-en ◽

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.

Download Full-text

Antigenic and genetic diversity among swine influenza A H1N1 and H1N2 viruses in Europe

Journal of General Virology ◽

10.1099/0022-1317-83-4-735 ◽

2002 ◽

Vol 83 (4) ◽

pp. 735-745 ◽

Cited By ~ 83

Author(s):

S. Marozin ◽

V. Gregory ◽

K. Cameron ◽

M. Bennett ◽

M. Valette ◽

...

Keyword(s):

Genetic Diversity ◽

Influenza A ◽

Swine Influenza ◽

Influenza Viruses ◽

Antigenic Drift ◽

H3n2 Virus ◽

Human Populations ◽

Antigenic Variant ◽

Influenza A H1n1 ◽

The Uk

Three subtypes of influenza A viruses, H1N1, H1N2 and H3N2, co-evolve in pigs in Europe. H1N2 viruses isolated from pigs in France and Italy since 1997 were closely related to the H1N2 viruses which emerged in the UK in 1994. In particular, the close relationship of the neuraminidases (NAs) of these viruses to the NA of a previous UK H3N2 swine virus indicated that they had not acquired the NA from H3N2 swine viruses circulating in continental Europe. Moreover, antigenic and genetic heterogeneity among the H1N2 viruses appeared to be due in part to multiple introductions of viruses from the UK. On the other hand, comparisons of internal gene sequences indicated genetic exchange between the H1N2 viruses and co-circulating H1N1 and/or H3N2 subtypes. Most genes of the earlier (1997–1998) H1N2 isolates were more closely related to those of a contemporary French H1N1 isolate, whereas the genes of later (1999–2000) isolates, including the HAs of some H1N2 viruses, were closely related to those of a distinct H1N1 antigenic variant which emerged in France in 1999. In contrast, an H3N2 virus isolated in France in 1999 was closely related antigenically and genetically to contemporary human A/Sydney/5/97-like viruses. These studies reveal interesting parallels between genetic and antigenic drift of H1N1 viruses in pig and human populations, and provide further examples of the contribution of genetic reassortment to the antigenic and genetic diversity of swine influenza viruses and the importance of the complement of internal genes in the evolution of epizootic strains.

Download Full-text

Molecular genetic factors of pathogenicity of influenza A virus (H1N1) pdm09

Epidemiology and Infectious Diseases (Russian Journal) ◽

10.17816/eid40804 ◽

2014 ◽

Vol 19 (4) ◽

pp. 4-11

Author(s):

V. V Tsvetkov ◽

E. G Deeva ◽

D. M Danilenko ◽

T. V Sologub ◽

E. P Tikhonova

Keyword(s):

Influenza Virus ◽

Pandemic Influenza ◽

Influenza A ◽

Far East ◽

Influenza Viruses ◽

Endocrine Disorders ◽

Human Virus ◽

Influenza Virus A ◽

The Far East ◽

Influenza A H1n1

Unlike influenza epidemics which affect the population almost yearly, pandemics occur much less frequently, but have more severe medical and social consequences. The investigation of the nature of the course of all modern epidemics and pandemics are acquiring the particular rationale. Pandemic influenza A (H1N1) 2009 was caused by the virus of the mixed (triple) origin. In Russia, the first three cases of disease have been identified in Moscow from 21 to 10 June 2009. In the Far East - 2-2,5 months later compared to the European part of Russia. However, the epidemic of influenza in Russia caused by influenza virus A (H1N1) pdm09, began and developed more rapidly just in the Far East. The highest morbidity rate (10,2-10,3 per 100 people) was registered in the cities of the Far Eastern and Siberian regions. The phylogenetic analysis allowed to reveal the origin of the triple reassortant virus A (H1N1)pdm09 out of H1N1, H1N2, H3N2 avian/porcine/human virus. The performed analysis of functional domains of proteins of the influenza virus A (H1N1) pdm09 showed that modern pandemic influenza viruses have several principal genetic defects, the totality of which permits to rank them to moderately pathogenic viruses. High risk of the severe course of influenza and occurrence of complications was noted in three groups ofpatients: pregnant women, especially in the 3 trimester ofpregnancy, children under 2 years of age and patients with concomitant chronic respiratory and cardiovascular systems, as well as patients with endocrine disorders and obesity.

Download Full-text

Experimental Infection of Pigs with the Human 1918 Pandemic Influenza Virus

Journal of Virology ◽

10.1128/jvi.02399-08 ◽

2009 ◽

Vol 83 (9) ◽

pp. 4287-4296 ◽

Cited By ~ 45

Author(s):

Hana M. Weingartl ◽

Randy A. Albrecht ◽

Kelly M. Lager ◽

Shawn Babiuk ◽

Peter Marszal ◽

...

Keyword(s):

Influenza Virus ◽

Pandemic Influenza ◽

H1n1 Virus ◽

Swine Influenza ◽

H1n1 Influenza ◽

Influenza Viruses ◽

H1n1 Influenza Virus ◽

Severe Respiratory Distress ◽

Pandemic H1n1 Influenza ◽

Spanish Flu

ABSTRACT Swine influenza was first recognized as a disease entity during the 1918 “Spanish flu” pandemic. The aim of this work was to determine the virulence of a plasmid-derived human 1918 pandemic H1N1 influenza virus (reconstructed 1918, or 1918/rec, virus) in swine using a plasmid-derived A/swine/Iowa/15/1930 H1N1 virus (1930/rec virus), representing the first isolated influenza virus, as a reference. Four-week-old piglets were inoculated intratracheally with either the 1930/rec or the 1918/rec virus or intranasally with the 1918/rec virus. A transient increase in temperature and mild respiratory signs developed postinoculation in all virus-inoculated groups. In contrast to other mammalian hosts (mice, ferrets, and macaques) where infection with the 1918/rec virus was lethal, the pigs did not develop severe respiratory distress or become moribund. Virus titers in the lower respiratory tract as well as macro- and microscopic lesions at 3 and 5 days postinfection (dpi) were comparable between the 1930/rec and 1918/rec virus-inoculated animals. In contrast to the 1930/rec virus-infected animals, at 7 dpi prominent lung lesions were present in only the 1918/rec virus-infected animals, and all the piglets developed antibodies at 7 dpi. Presented data support the hypothesis that the 1918 pandemic influenza virus was able to infect and replicate in swine, causing a respiratory disease, and that the virus was likely introduced into the pig population during the 1918 pandemic, resulting in the current lineage of the classical H1N1 swine influenza viruses.

Download Full-text

Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu

Journal of Virology ◽

10.1128/jvi.00101-10 ◽

2010 ◽

Vol 84 (9) ◽

pp. 4587-4596 ◽

Cited By ~ 32

Author(s):

Alicia Solórzano ◽

Jianqiang Ye ◽

Daniel R. Pérez

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Influenza Vaccine ◽

Pandemic Influenza ◽

Vaccine Development ◽

Swine Influenza Virus ◽

Influenza Viruses ◽

H3n2 Virus ◽

Avian Influenza Viruses ◽

Ann Arbor

ABSTRACT Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the PB1 and PB2 mutations could be further attenuated by stably introducing a hemagglutinin (HA) epitope tag in the PB1 gene. In this work, we wanted to determine whether these modifications would also result in attenuation of a so-called triple reassortant (TR) swine influenza virus (SIV). Thus, the TR influenza A/swine/Wisconsin/14094/99 (H3N2) virus was generated by reverse genetics and subsequently mutated in the PB1 and PB2 genes. Here we show that a combination of mutations in this TR backbone results in an attenuated virus in vitro and in vivo. Furthermore, we show the potential of our TR backbone as a vaccine that provides protection against the 2009 swine-origin pandemic influenza H1N1 virus (S-OIV) when carrying the surface of a classical swine strain. We propose that the availability of alternative backbones to the conventional ca A/Ann Arbor/6/60 LAIV strain could also be useful in epidemic and pandemic influenza and should be considered for influenza vaccine development. In addition, our data provide evidence that the use of these alternative backbones could potentially circumvent the effects of original antigenic sin (OAS) in certain circumstances.

Download Full-text

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

Vaccines ◽

10.3390/vaccines9070793 ◽

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.

Download Full-text

Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

Annals of Clinical Chemistry and Laboratory Medicine ◽

10.3126/acclm.v3i2.20737 ◽

2018 ◽

Vol 3 (2) ◽

pp. 1-2

Author(s):

Bishnu Prasad Upadhyay

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Winter Season ◽

Emerging Infectious Diseases ◽

Influenza Viruses ◽

Influenza B ◽

Influenza A Viruses ◽

Influenza A H1n1 ◽

New Variant ◽

Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

Download Full-text