scholarly journals Influenza in the United Kingdom 1982–85

1986 ◽  
Vol 97 (2) ◽  
pp. 347-358 ◽  
Author(s):  
P. Chakraverty ◽  
P. Cunningham ◽  
G. Z. Shen ◽  
M. S. Pereira
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Severe Disease ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Unexpected Finding ◽  
National Statistics ◽  
The United Kingdom ◽  
The Uk

SummaryInfluenza surveillance in the UK between the years 1982 and 1985 has demonstrated the regular winter appearance of influenza A virus of both H1N1 and H3N2 subtypes and influenza B.Their antigenic diversity is described and correlated with the national statistics for morbidity and mortality for influenza.One unexpected finding has been that despite the wide circulation of influenza viruses there has been a continuation of winters without significant increases in influenza deaths or morbidity. A previous report of influenza surveillance (Pereira & Chakraverty, 1982) noted an already unusual series of three consecutive winters with this pattern. This report records a further 4 years bringing a total of seven successive winters without evidence of epidemics of severe disease associated with influenza viruses, as indicated by the national UK statistics.

scholarly journals Effectiveness of seasonal influenza vaccine for adults and children in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2015/16 end-of-season results

2016 ◽  
Vol 21 (38) ◽  
Author(s):  
Richard Pebody ◽  
Fiona Warburton ◽  
Joanna Ellis ◽  
Nick Andrews ◽  
Alison Potts ◽  
...  
Keyword(s):  
Primary Care ◽  
United Kingdom ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Immunisation Programme ◽  
Influenza B ◽  
Live Attenuated Influenza Vaccine ◽  
The United Kingdom ◽  
Influenza A H1n1 ◽  
The Uk

The United Kingdom (UK) is in the third season of introducing universal paediatric influenza vaccination with a quadrivalent live attenuated influenza vaccine (LAIV). The 2015/16 season in the UK was initially dominated by influenza A(H1N1)pdm09 and then influenza of B/Victoria lineage, not contained in that season’s adult trivalent inactivated influenza vaccine (IIV). Overall adjusted end-of-season vaccine effectiveness (VE) was 52.4% (95% confidence interval (CI): 41.0–61.6) against influenza-confirmed primary care consultation, 54.5% (95% CI: 41.6–64.5) against influenza A(H1N1)pdm09 and 54.2% (95% CI: 33.1–68.6) against influenza B. In 2–17 year-olds, adjusted VE for LAIV was 57.6% (95% CI: 25.1 to 76.0) against any influenza, 81.4% (95% CI: 39.6–94.3) against influenza B and 41.5% (95% CI: −8.5 to 68.5) against influenza A(H1N1)pdm09. These estimates demonstrate moderate to good levels of protection, particularly against influenza B in children, but relatively less against influenza A(H1N1)pdm09. Despite lineage mismatch in the trivalent IIV, adults younger than 65 years were still protected against influenza B. These results provide reassurance for the UK to continue its influenza immunisation programme planned for 2016/17.

scholarly journals Clinical Investigations. Comparison of Directigen Flu A+B with Real Time PCR in the Diagnosis of Influenza / Сравнение Иммунохроматографического Метода (Directigen Flu A+B) И Теста RT-PCR При Инфекциях Гриппа

Folia Medica ◽  
2015 ◽  
Vol 57 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Golubinka Bosevska ◽  
Nikola Panovski ◽  
Elizabeta Janceska ◽  
Vladimir Mikik ◽  
Irena Kondova Topuzovska ◽  
...  
Keyword(s):  
Real Time ◽  
Influenza A Virus ◽  
Real Time Pcr ◽  
Influenza A ◽  
Age Groups ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
B Virus ◽  
Nose And Throat

AbstractEarly diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. MATERIALS AND METHODS: One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0 - 4 yrs, 5 - 9 yrs, 10 - 14 yrs, 15 - 19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. RESULTS: Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. CONCLUSION: Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.

Influenza Project in Myanmar

2014 ◽  
Vol 9 (5) ◽  
pp. 842-847
Author(s):  
Reiko Saito ◽  
◽  
Yadanar Kyaw ◽  
Yi Yi Myint ◽  
Clyde Dapat ◽  
...  
Keyword(s):  
Influenza A ◽  
Drug Susceptibility ◽  
Influenza Viruses ◽  
World Health ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Laboratory Capacity ◽  
Influenza A H1n1 ◽  
Resistant Strains ◽  
Health Organization

The epidemiological study of influenza in Southeast Asia is limited. We surveyed influenza in Myanmar from 2007 to 2013. Nasopharyngeal swabs were collected from patients in the two cities of Yangon and Nay Pyi Taw. Samples were screened using rapid influenza diagnostic kits and identified by virus isolation. Isolates were characterized by cyclingprobe-based real-time PCR, drug susceptibility assay, and sequencing. Samples collected numbered 5,173, from which 1,686 influenza viruses were isolated during the seven-year study period. Of these, 187 strains were of seasonal influenza A(H1N1), 274 of influenza A(H1N1)pdm09, 791 of influenza A(H3N2), and 434 of influenza B. Interestingly, two zanamivir and amantadine-resistant strains each were detected in 2007 and 2008. These rare dual-resistant strains had a Q136K mutation in the NA protein and S31N substitution in the M2 protein. Our collaboration raised the influenza surveillance laboratory capacity in Myanmar and led Yangon’s National Health Laboratory – one of the nation’s leading research institutes – to being designated a National Influenza Center by the World Health Organization.

scholarly journals What will the next influenza season bring about: seasonal influenza or the new A(H1N1)v? An analysis of German influenza surveillance data

2009 ◽  
Vol 14 (32) ◽  
Author(s):  
H Uphoff ◽  
S Geis ◽  
A Grüber ◽  
A M Hauri
Keyword(s):  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza Season ◽  
Influenza Viruses ◽  
Moderate Intensity ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Low Intensity ◽  
Influenza A H1n1 ◽  
Using Data

For the next influenza season (winter 2009-10) the relative contributions to virus circulation and influenza-associated morbidity of the seasonal influenza viruses A(H3N2), A(H1N1) and B, and the new influenza A(H1N1)v are still unknown. We estimated the chances of seasonal influenza to circulate during the upcoming season using data of the German influenza sentinel scheme from 1992 to 2009. We calculated type and subtype-specific indices for past exposure and the corresponding morbidity indices for each season. For the upcoming season 2009-10 our model suggests that it is unlikely that influenza A(H3N2) will circulate with more than a low intensity, seasonal A(H1N1) with more than a low to moderate intensity, and influenza B with more than a low to median intensity. The probability of a competitive circulation of seasonal influenza A with the new A(H1N1)v is low, increasing the chance for the latter to dominate the next influenza season in Germany.

scholarly journals Influenza B viruses exhibit lower within-host diversity than influenza A viruses in human hosts

2019 ◽  
Author(s):  
Andrew L. Valesano ◽  
William J. Fitzsimmons ◽  
John T. McCrone ◽  
Joshua G. Petrie ◽  
Arnold S. Monto ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Influenza A Virus ◽  
Influenza A ◽  
Evolutionary Dynamics ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Community Based ◽  
B Virus

AbstractInfluenza B virus undergoes seasonal antigenic drift more slowly than influenza A, but the reasons for this difference are unclear. While the evolutionary dynamics of influenza viruses play out globally, they are fundamentally driven by mutation, reassortment, drift, and selection within individual hosts. These processes have recently been described for influenza A virus, but little is known about the evolutionary dynamics of influenza B virus (IBV) at the level of individual infections and transmission events. Here we define the within-host evolutionary dynamics of influenza B virus by sequencing virus populations from naturally-infected individuals enrolled in a prospective, community-based cohort over 8176 person-seasons of observation. Through analysis of high depth-of-coverage sequencing data from samples from 91 individuals with influenza B, we find that influenza B virus accumulates lower genetic diversity than previously observed for influenza A virus during acute infections. Consistent with studies of influenza A viruses, the within-host evolution of influenza B viruses is characterized by purifying selection and the general absence of widespread positive selection of within-host variants. Analysis of shared genetic diversity across 15 sequence-validated transmission pairs suggests that IBV experiences a tight transmission bottleneck similar to that of influenza A virus. These patterns of local-scale evolution are consistent with influenza B virus’ slower global evolutionary rate.ImportanceThe evolution of influenza virus is a significant public health problem and necessitates the annual evaluation of influenza vaccine formulation to keep pace with viral escape from herd immunity. Influenza B virus is a serious health concern for children, in particular, yet remains understudied compared to influenza A virus. Influenza B virus evolves more slowly than influenza A, but the factors underlying this are not completely understood. We studied how the within-host diversity of influenza B virus relates to its global evolution by sequencing viruses from a community-based cohort. We found that influenza B virus populations have lower within-host genetic diversity than influenza A virus and experience a tight genetic bottleneck during transmission. Our work provides insights into the varying dynamics of influenza viruses in human infection.

scholarly journals Establishment of pan-Influenza A (H1-H18) and pan-Influenza B (pre-split, Vic/Yam) Pseudotype Libraries for efficient vaccine antigen selection

2021 ◽  
Author(s):  
Joanne M Del Rosario ◽  
Kelly da Costa ◽  
Benedikt Asbach ◽  
Francesca Ferrara ◽  
Matteo Ferrari ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Influenza Viruses ◽  
Vaccine Antigen ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Strategic Objectives ◽  
Influenza Hemagglutinin ◽  
Dosing Regimens

We have developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18, and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for de-tecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza serological and neutralization assays. We demonstrate its utility in detecting serum response to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further pre-clinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response.

scholarly journals Defective interfering influenza A virus protects in vivo against disease caused by a heterologous influenza B virus

2011 ◽  
Vol 92 (9) ◽  
pp. 2122-2132 ◽  
Author(s):  
Paul D. Scott ◽  
Bo Meng ◽  
Anthony C. Marriott ◽  
Andrew J. Easton ◽  
Nigel J. Dimmock
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Type I ◽  
Type I Ifn ◽  
B Virus ◽  
The Family

Influenza A and B viruses are major human respiratory pathogens that contribute to the burden of seasonal influenza. They are both members of the family Orthomyxoviridae but do not interact genetically and are classified in different genera. Defective interfering (DI) influenza viruses have a major deletion of one or more of their eight genome segments, which renders them both non-infectious and able to interfere in cell culture with the production of infectious progeny by a genetically compatible, homologous virus. It has been shown previously that intranasal administration of a cloned DI influenza A virus, 244/PR8, protects mice from various homologous influenza A virus subtypes and that it also protects mice from respiratory disease caused by a heterologous virus belonging to the family Paramyxoviridae. The mechanisms of action in vivo differ, with homologous and heterologous protection being mediated by probable genome competition and type I interferon (IFN), respectively. In the current study, it was shown that 244/PR8 also protects against disease caused by a heterologous influenza B virus (B/Lee/40). Protection from B/Lee/40 challenge was partially eliminated in mice that did not express a functional type I IFN receptor, suggesting that innate immunity, and type I IFN in particular, are important in mediating protection against this virus. It was concluded that 244/PR8 has the ability to protect in vivo against heterologous IFN-sensitive respiratory viruses, in addition to homologous influenza A viruses, and that it acts by fundamentally different mechanisms.

scholarly journals Report on influenza viruses received and tested by the Melbourne WHO Collaborating Centre for Reference and Research on Influenza in 2017

2019 ◽  
Vol 43 ◽  
Author(s):  
Merryn Roe ◽  
Matthew Kaye ◽  
Pina Iannello ◽  
Hilda Lau ◽  
Iwona Buettner ◽  
...  
Keyword(s):  
Influenza A ◽  
Seasonal Influenza ◽  
Vaccine Virus ◽  
Influenza Viruses ◽  
World Health ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Neuraminidase Inhibitors ◽  
Response System ◽  
Surveillance And Response

As part of its role in the World Health Organization’s (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received a record total of 5866 human influenza positive samples during 2017. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties and were propagated in qualified cells and hens’ eggs for use as potential seasonal influenza vaccine virus candidates. In 2017, influenza A(H3) viruses predominated over influenza A(H1)pdm09 and B viruses, accounting for a total of 54% of all viruses analysed. The majority of A(H1)pdm09, A(H3) and influenza B viruses analysed at the Centre were found to be antigenically similar to the respective WHO recommended vaccine strains for the Southern Hemisphere in 2017. However, phylogenetic analysis indicated that the majority of circulating A(H3) viruses had undergone genetic drift relative to the WHO recommended vaccine strain for 2017. Of 3733 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, only two A(H1)pdm09 viruses and one A(H3) virus showed highly reduced inhibition by oseltamivir, while just one A(H1)pdm09 virus showed highly reduced inhibition by zanamivir.

scholarly journals Analysis of influenza A virus reinfection in children in Japan during 1983–91

1995 ◽  
Vol 115 (3) ◽  
pp. 591-601 ◽  
Author(s):  
S. Nakajima ◽  
F. Nishikawa ◽  
K. Nakamura ◽  
K. Nakajima
Keyword(s):  
Amino Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Haemagglutination Inhibition ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
H3n2 Virus ◽  
Influenza B ◽  
Influenza A H1n1 ◽  
Influenza H3n2

SummaryThe epidemiology of influenza A in Japan was studied during 1979–91 and viruses isolated from reinfections during 1983–91 were analysed, Of 2963 influenza viruses isolated during this period, 922 and 1006 were influenza A(H1N1) and A(H3N2) viruses respectively; the others were influenza B viruses. Influenza A(H1N1) and A(H3N2) caused 5 and 6 epidemics respectively, most accompanied by antigenic drift. Seventeen reinfections with H1N1 and 17 with H3N2 were detected during our study. The primary and reinfection strains isolated from 7 H1N1 and 10 H3N2 cases were studied by haemagglutination-inhibition, and amino acid and nucleotide sequences of the HA1 region of the haemagglutinin. Most of the primary and reinfection strains were antigenically and genetically similar to the epidemic viruses circulating at that time. However, in 4 out of 10 cases of reinfection with influenza H3N2 virus, reinfection strains were genetically different from the epidemic viruses.

scholarly journals The Influenza B Virus Hemagglutinin Head Domain Is Less Tolerant to Transposon Mutagenesis than That of the Influenza A Virus

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Benjamin O. Fulton ◽  
Weina Sun ◽  
Nicholas S. Heaton ◽  
Peter Palese
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Antigenic Variation ◽  
Transposon Mutagenesis ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Antigenic Sites ◽  
Head Domain ◽  
B Virus

ABSTRACTInfluenza A and B viruses can continuously evade humoral immune responses by developing mutations in the globular head of the hemagglutinin (HA) that prevent antibody binding. However, the influenza B virus HA over time displays less antigenic variation despite being functionally and structurally similar to the influenza A virus HA. To determine if the influenza B virus HA is under constraints that limit its antigenic variation, we performed a transposon screen to compare the mutational tolerance of the currently circulating influenza A virus HAs (H1 and H3 subtypes) and influenza B virus HAs (B/Victoria87 and B/Yamagata88 antigenic lineages). A library of insertional mutants for each HA was generated and deep sequenced after passaging to determine where insertions were tolerated in replicating viruses. The head domains of both viruses tolerated transposon mutagenesis, but the influenza A virus head was more tolerant to insertions than the influenza B virus head domain. Furthermore, all five of the known antigenic sites of the influenza A virus HA were tolerant of 15 nucleotide insertions, while insertions were detected in only two of the four antigenic sites in the influenza B virus head domain. Our analysis demonstrated that the influenza B virus HA is inherently less tolerant of transposon-mediated insertions than the influenza A virus HA. The reduced insertional tolerance of the influenza B virus HA may reveal genetic restrictions resulting in a lower capacity for antigenic evolution.IMPORTANCEInfluenza viruses cause seasonal epidemics and result in significant human morbidity and mortality. Influenza viruses persist in the human population through generating mutations in the hemagglutinin head domain that prevent antibody recognition. Despite the similar selective pressures on influenza A and B viruses, influenza A virus displays a higher rate and breadth of antigenic variability than influenza B virus. A transposon mutagenesis screen was used to examine if the reduced antigenic variability of influenza B virus was due to inherent differences in mutational tolerance. This study demonstrates that the influenza A virus head domain and the individual antigenic sites targeted by humoral responses are more tolerant to insertions than those of influenza B virus. This finding sheds light on the genetic factors controlling the antigenic evolution of influenza viruses.

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