scholarly journals Prevalence of Antibodies against Seasonal Influenza A and B Viruses in Children in Netherlands

2011 ◽  
Vol 18 (3) ◽  
pp. 469-476 ◽  
Author(s):  
R. Bodewes ◽  
G. de Mutsert ◽  
F. R. M. van der Klis ◽  
M. Ventresca ◽  
S. Wilks ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Population Based ◽  
Influenza Viruses ◽  
Serum Samples ◽  
Cross Sectional ◽  
Population Based Study ◽  
Influenza A H1n1 ◽  
First Time

ABSTRACTTo gain insight into the age at which children become infected with influenza viruses for the first time, we analyzed the seroprevalence of antibodies against influenza viruses in children 0 to 7 years of age in the Netherlands. Serum samples were collected during a cross-sectional population-based study in 2006 and 2007 and were tested for the presence of antibodies against influenza A/H1N1, A/H3N2, and B viruses representative of viruses present in previous influenza seasons using the hemagglutination inhibition assay. The seroprevalence of antibodies to influenza virus was higher in children 1 to 6 months of age than in children 7 to 12 months of age, which likely reflects the presence of maternally derived antibodies. The proportion of study subjects >1 year of age with detectable antibodies against influenza viruses gradually increased with age until they reached the age of 6 years, when they all had antibodies to at least one influenza A virus. These findings may have implications for the development of vaccination strategies aiming at the protection of young children against seasonal and/or pandemic influenza virus infection.

scholarly journals Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16

2018 ◽  
Vol 23 (7) ◽  
Author(s):  
Hamutal Yaron-Yakoby ◽  
Hanna Sefty ◽  
Rakefet Pando ◽  
Rita Dichtiar ◽  
Mark A Katz ◽  
...  
Keyword(s):  
Primary Care ◽  
Influenza Virus ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Influenza Season ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Influenza B ◽  
Negative Case ◽  
Influenza A H1n1

Introduction Influenza vaccine is recommended for the entire population in Israel. We assessed influenza vaccine effectiveness (VE) for the 2014/15 and 2015/16 seasons in Israel, for the first time. Methods: Combined nose and throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to sentinel primary care clinics and tested for influenza virus by RT-PCR. VE of the trivalent inactivated vaccine (TIV) was assessed using test-negative case–control design. Results: During the 2014/15 season 1,142 samples were collected; 327 (28.6%) were positive for influenza, 83.8% A(H3N2), 5.8% A(H1N1)pdm09, 9.2% B and 1.2% A un-subtyped. Adjusted VE against all influenza viruses for this influenza season was −4.8% (95% confidence interval (CI): −54.8 to 29.0) and against influenza A(H3N2), it was −15.8% (95% CI: −72.8 to 22.4). For the 2015/16 season, 1,919 samples were collected; 853 (44.4%) were positive for influenza, 43.5% A(H1N1)pdm09, 57% B, 0.7% A(H3N2) and 11 samples positive for both A(H1N1)pdm09 and B. Adjusted VE against all influenza viruses for this influenza season was 8.8% (95% CI: −25.1 to 33.5), against influenza A(H1N1)pdm09, it was 32.3% (95% CI: (−4.3 to 56.1) and against influenza B, it was −2.2% (95% CI: (−47.0 to 29.0). Conclusions: Using samples from patients with ILI visiting sentinel clinics in Israel, we demonstrated the feasibility of influenza VE estimation in Israel.

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

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.

scholarly journals Methods for Molecular Surveillance of Influenza Used in Macedonia

PRILOZI ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 25-30
Author(s):  
Golubinka Bosevska ◽  
Elizabeta Janceska ◽  
Gordana Kuzmanovska ◽  
Vladimir Mikik ◽  
Nikola Panovski
Keyword(s):  
Influenza Virus ◽  
Predictive Value ◽  
Influenza A ◽  
Rna Extraction ◽  
Influenza Virus Infection ◽  
Laboratory Diagnosis ◽  
Influenza Viruses ◽  
Rt Pcr ◽  
Two Samples ◽  
Nose And Throat

AbstractThe aim: To present and compare different Nucleic Acid Testing assays used for laboratory diagnosis of influenza virus infection in our country.Materials and methods: Respiratory samples used were nose and throat swabs. The RNA extraction was performed with a QIAamp viral RNA kit. During the season 2009–2010 the first 25 samples were tested with: conventional gel-based RT-PCR and CDC rtRT-PCR using published specific matrix and HA gene primers and probes for influenza virus typing and subtyping.Results: Of 25 samples tested with conventional RT-PCR7(28%) were positive for influenza A, but negative for A/H1seasonal and A/H3. Retested with rtRT-PCR 9(36%) were positive for influenza A, 8(32%) were positive for A/H1pdm and 1(4%) was A/H3. Two samples positive with rtRT-PCR for influenza A were negative with RT-PCR. The sensitivity of the RT-PCR in comparison with rtRT-PCR is 100% and the specificity is 88.89%. Positive predictive value for RT-PCR is 77.78%, and negative predictive value is 100%. RT-PCR is a four-step and rtRT-PCR a one-step procedure. The turn-around time of RT-PCR is 6 hours and for rtRT-PCR it is 2 hours.Discussion and conclusion: For surveillance purposes nose and throat swabs are the more easy and practical to collect. It was proved that RT-PCR is too laborious, multi-step and time-consuming. The sensitivity of both assays is equal. The specificity of rtRT-PCR is higher. NAT assays for detection of influenza viruses have become an integral component of the surveillance programme in our country. They provide a fast, accurate and sensitive detection of influenza.

scholarly journals Emergence of H7N9 Influenza A Virus Resistant to Neuraminidase Inhibitors in Nonhuman Primates

2015 ◽  
Vol 59 (8) ◽  
pp. 4962-4973 ◽  
Author(s):  
Yasushi Itoh ◽  
Shintaro Shichinohe ◽  
Misako Nakayama ◽  
Manabu Igarashi ◽  
Akihiro Ishii ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Cynomolgus Macaque ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
H7n9 Virus ◽  
Macaque Model ◽  
H7n9 Influenza Virus ◽  
Number Of Patients ◽  
H7n9 Influenza

ABSTRACTThe number of patients infected with H7N9 influenza virus has been increasing since 2013. We examined the efficacy of neuraminidase (NA) inhibitors and the efficacy of a vaccine against an H7N9 influenza virus, A/Anhui/1/2013 (H7N9), isolated from a patient in a cynomolgus macaque model. NA inhibitors (oseltamivir and peramivir) barely reduced the total virus amount because of the emergence of resistant variants with R289K or I219T in NA [residues 289 and 219 in N9 of A/Anhui/1/2013 (H7N9) correspond to 292 and 222 in N2, respectively] in three of the six treated macaques, whereas subcutaneous immunization of an inactivated vaccine derived from A/duck/Mongolia/119/2008 (H7N9) prevented propagation of A/Anhui/1/2013 (H7N9) in all vaccinated macaques. The percentage of macaques in which variant H7N9 viruses with low sensitivity to the NA inhibitors were detected was much higher than that of macaques in which variant H5N1 highly pathogenic influenza virus was detected after treatment with one of the NA inhibitors in our previous study. The virus with R289K in NA was reported in samples from human patients, whereas that with I219T in NA was identified for the first time in this study using macaques, though no variant H7N9 virus was reported in previous studies using mice. Therefore, the macaque model enables prediction of the frequency of emerging H7N9 virus resistant to NA inhibitorsin vivo. Since H7N9 strains resistant to NA inhibitors might easily emerge compared to other influenza viruses, monitoring of the emergence of variants is required during treatment of H7N9 influenza virus infection with NA inhibitors.

scholarly journals Acceptability of A/H1N1 vaccination during pandemic phase of influenza A/H1N1 in Hong Kong: population based cross sectional survey

BMJ ◽  
2009 ◽  
Vol 339 (oct27 1) ◽  
pp. b4164-b4164 ◽  
Author(s):  
J. T F Lau ◽  
N. C Y Yeung ◽  
K C Choi ◽  
M. Y M Cheng ◽  
H Y Tsui ◽  
...  
Keyword(s):  
Hong Kong ◽  
Influenza A ◽  
Population Based ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Influenza A H1n1

HA1-2-fljB Vaccine Induces Immune Responses against Pandemic Swine-Origin H1N1 Influenza Virus in Mice

2016 ◽  
Vol 26 (6) ◽  
pp. 422-432 ◽  
Author(s):  
Xilong Kang ◽  
Yun Yang ◽  
Yang Jiao ◽  
Hongqin Song ◽  
Li Song ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Influenza Virus Infection ◽  
Candidate Vaccine ◽  
Major Barrier ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Influenza A H1n1 ◽  
N Terminus

In 2009, a novel pandemic swine-origin influenza A (H1N1) virus caused a public emergency of international concern. Vaccination is the primary strategy for the control of influenza epidemics. However, the poor immunopotency of many vaccine antigens is a major barrier to the development of effective vaccines against influenza. Flagellin, a Toll-like receptor 5 (TLR5) ligand, has been used as an adjuvant to enhance the immunopotency of vaccines in preclinical studies. Here, we developed a recombinant candidate vaccine, HA1-2-fljB, in which the globular head of the hemagglutinin (HA) antigen (residues 62-284) from H1N1 virus was fused genetically to the N-terminus of <i>Salmonella typhimurium</i> &#xFB02;jB. The recombinant HA1-2-fljB protein was expressed efficiently in<i> Escherichia coli</i>, and the immunogenicity and protective efficacy of recombinant HA1-2-fljB were evaluated in a mouse model. Immunization with HA1-2-fljB elicited robust IgG antibodies and neutralizing antibodies and completely protected the mice against infection by swine-origin influenza A/swine/Jangsu/38/2010 (H1N1). These results suggest that HA antigen placed at the N-terminus of flagellin is also an excellent starting point for creating a fusion HA1-2-fljB protein as a candidate vaccine, and the recombinant HA1-2-fljB protein will contribute to the development of a more effective vaccine against swine-origin influenza virus infection.

Dual and Triple Infections With Influenza A and B Viruses: A Case-Control Study in Southern Brazil

2019 ◽  
Vol 220 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Tatiana Schäffer Gregianini ◽  
Ivana R Santos Varella ◽  
Patricia Fisch ◽  
Letícia Garay Martins ◽  
Ana B G Veiga
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Clinical Symptoms ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
H3n2 Virus ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A H1n1

Abstract Influenza surveillance is important for disease control and should consider possible coinfection with different viruses, which can be associated with disease severity. This study analyzed 34 459 patients with respiratory infection from 2009 to 2018, of whom 8011 were positive for influenza A virus (IAV) or influenza B virus (IBV). We found 18 cases of dual influenza virus infection, including coinfection with 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09) and influenza A(H3N2) virus (1 case), A(H1N1)pdm09 and IBV (6 cases), A(H3N2) and IBV (8 cases), and nonsubtyped IAV and IBV (3 cases); and 1 case of triple infection with A(H3N2), A(H1N1)pdm09, and IBV. Compared with 76 monoinfected patients, coinfection was significantly associated with cardiopathy and death. Besides demographic characteristics and clinical symptoms, we assessed vaccination status, antiviral treatment, timeliness of antiviral use, hospitalization, and intensive care unit admission, but no significant differences were found between coinfected and monoinfected cases. Our findings indicate that influenza virus coinfection occurs more often than previously reported and that it can lead to a worse disease outcome.

scholarly journals Molecular Epidemiology and Antigenic Characterization of Seasonal Influenza Viruses Circulating in Nepal

2017 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Bishu Prasad Upadhyay ◽  
Prakash Ghimire ◽  
Masato Tashiro ◽  
Mogha Raj Banjara
Keyword(s):  
New York ◽  
Influenza Virus ◽  
Molecular Epidemiology ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Antigenic Characterization ◽  
Geographical Regions ◽  
Influenza A H1n1 ◽  
Health Burdens

Background: Influenza is one of the public health burdens in Nepal and its epidemiology is not clearly understood. The objective of this study was to explore the molecular epidemiology and the antigenic characteristics of the circulating influenza viruses in Nepal.Methods: A total of 1495 throat swab specimens were collected from January to December, 2014. Real time PCR assay was used for identification of influenza virus types and subtypes. Ten percent of the positive specimens were randomly selected and inoculated onto Madin-Darby Canine Kidney Epithelial cells (MDCK) for influenza virus isolation. All viruses were characterized by the hemagglutination inhibition (HI) assay.Results: Influenza viruses were detected in 421/1495 (28.2%) specimens. Among positive cases, influenza A virus was detected in 301/421 (71.5%); of which 120 (39.9%) were influenza A/H1N1 pdm09 and 181 (60.1%) were influenza A/H3 subtype. Influenza B viruses were detected in 119/421 (28.3%) specimens. Influenza A/H1N1 pdm09, A/H3 and B viruses isolated in Nepal were antigenically similar to the vaccine strain influenza A/California/07/2009(H1N1pdm09), A/Texas/50/2012(H3N2), A/New York/39/2012(H3N2) and B/Massachusetts/2/2012, respectively.Conclusions: Influenza viruses were reported year-round in different geographical regions of Nepal which was similar to other tropical countries. The circulating influenza virus type and subtypes of Nepal were similar to vaccine candidate virus which could be prevented by currently used influenza vaccine.

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