scholarly journals Characterization of Influenza B Virus Variants with Reduced Neuraminidase Inhibitor Susceptibility

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
R. Farrukee ◽  
A. E. Zarebski ◽  
J. M. McCaw ◽  
J. D. Bloom ◽  
P. C. Reading ◽  
...  
Keyword(s):  
Treatment Options ◽  
Transmission Efficiency ◽  
Enzyme Function ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
Wild Type ◽  
B Virus ◽  
Na Substitution

ABSTRACT Treatment options for influenza B virus infections are limited to neuraminidase inhibitors (NAIs), which block the neuraminidase (NA) glycoprotein on the virion surface. The development of NAI resistance would therefore result in a loss of antiviral treatment options for influenza B virus infections. This study characterized two contemporary influenza B viruses with known resistance-conferring NA amino acid substitutions, D197N and H273Y, detected during routine surveillance. The D197N and H273Y variants were characterized in vitro by assessing NA enzyme activity and affinity, as well as replication in cell culture compared to those of NAI-sensitive wild-type viruses. In vivo studies were also performed in ferrets to assess the replication and transmissibility of each variant. Mathematical models were used to analyze within-host and between-host fitness of variants relative to wild-type viruses. The data revealed that the H273Y variant had NA enzyme function similar to that of its wild type but had slightly reduced replication and transmission efficiency in vivo. The D197N variant had impaired NA enzyme function, but there was no evidence of reduction in replication or transmission efficiency in ferrets. Our data suggest that the influenza B virus variant with the H273Y NA substitution had a more notable reduction in fitness compared to wild-type viruses than the influenza B variant with the D197N NA substitution. Although a D197N variant is yet to become widespread, it is the most commonly detected NAI-resistant influenza B virus in surveillance studies. Our results highlight the need to carefully monitor circulating viruses for the spread of influenza B viruses with the D197N NA substitution.

scholarly journals Characterization of influenza B virus variants with reduced neuraminidase inhibitor susceptibility

2018 ◽  
Author(s):  
R Farrukee ◽  
AE Zarebski ◽  
JM McCaw ◽  
JD Bloom ◽  
PC Reading ◽  
...  
Keyword(s):  
Antiviral Treatment ◽  
Treatment Options ◽  
Transmission Efficiency ◽  
Enzyme Function ◽  
Influenza B Virus ◽  
Influenza B ◽  
Wild Type ◽  
B Virus ◽  
Na Substitution

AbstractTreatment options for influenza B virus infections are limited to neuraminidase inhibitors (NAIs) which block the neuraminidase (NA) glycoprotein on the virion surface. The development of NAI resistance would therefore result in a loss of antiviral treatment options for influenza B infections. This study characterized two contemporary influenza B viruses with known resistance-conferring NA amino acid substitutions, D197N and H273Y, detected during routine surveillance. The D197N and H273Y variants were characterized in vitro by assessing NA enzyme activity and affinity, as well as replication in cell culture compared to NAI-sensitive wild-type viruses. In vivo studies were also performed in ferrets to assess the replication and transmissibility of each variant. Mathematical models were used to analyse within-host and between-host fitness of variants relative to wild-type viruses. The data revealed that the H273Y variant had similar NA enzyme function relative to its wild-type but had slightly reduced replication and transmission efficiency in vivo. The D197N variant had impaired NA enzyme function but there was no evidence of reduction in replication or transmission efficiency in ferrets. Our data suggest that the influenza B variant with H273Y NA substitution had a more notable reduction in fitness compared to wild-type viruses than the influenza B variant with the D197N NA substitution. Although a D197N variant is yet to become widespread, it is the most commonly detected NAI-resistant influenza B virus in surveillance studies. Our results highlight the need to carefully monitor circulating viruses for the spread of influenza B viruses with the D197N NA substitution.

scholarly journals The NB Protein of Influenza B Virus Is Not Necessary for Virus Replication In Vitro

2003 ◽  
Vol 77 (10) ◽  
pp. 6050-6054 ◽  
Author(s):  
Masato Hatta ◽  
Yoshihiro Kawaoka
Keyword(s):  
Cell Culture ◽  
Virus Replication ◽  
Wild Type Virus ◽  
Influenza B Virus ◽  
Influenza B ◽  
Type Virus ◽  
Wild Type ◽  
B Virus

ABSTRACT The NB protein of influenza B virus is thought to function as an ion channel and therefore would be expected to have an essential function in viral replication. Because direct evidence for its absolute requirement in the viral life cycle is lacking, we generated NB knockout viruses by reverse genetics and tested their growth properties both in vitro and in vivo. Mutants not expressing NB replicated as efficiently as the wild-type virus in cell culture, whereas in mice they showed restricted growth compared with findings for the wild-type virus. Thus, the NB protein is not essential for influenza B virus replication in cell culture but promotes efficient growth in mice.

scholarly journals Recurring Influenza B Virus Infections in Seals

2013 ◽  
Vol 19 (3) ◽  
pp. 511-512 ◽  
Author(s):  
Rogier Bodewes ◽  
Danny Morick ◽  
Gerrie de Mutsert ◽  
Nynke Osinga ◽  
Theo Bestebroer ◽  
...  
Keyword(s):  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
B Virus

scholarly journals Influenza B virus infections in Western Saxony, Germany in three consecutive seasons between 2015 and 2018: Analysis of molecular and clinical features

Vaccine ◽  
2019 ◽  
Vol 37 (43) ◽  
pp. 6550-6557 ◽  
Author(s):  
M. Hönemann ◽  
D. Martin ◽  
C. Pietsch ◽  
M. Maier ◽  
S. Bergs ◽  
...  
Keyword(s):  
Clinical Features ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
B Virus

scholarly journals Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004–2017

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Simona Puzelli ◽  
◽  
Angela Di Martino ◽  
Marzia Facchini ◽  
Concetta Fabiani ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Illness ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
Ha Gene ◽  
B Virus ◽  
B Lineage ◽  
Trivalent Vaccine

Abstract Background Since 1985, two antigenically distinct lineages of influenza B viruses (Victoria-like and Yamagata-like) have circulated globally. Trivalent seasonal influenza vaccines contain two circulating influenza A strains but a single B strain and thus provide limited immunity against circulating B strains of the lineage not included in the vaccine. In this study, we describe the characteristics of influenza B viruses that caused respiratory illness in the population in Italy over 13 consecutive seasons of virological surveillance, and the match between the predominant influenza B lineage and the vaccine B lineage, in each season. Methods From 2004 to 2017, 26,886 laboratory-confirmed influenza cases were registered in Italy, of which 18.7% were type B. Among them, the lineage of 2465 strains (49%) was retrieved or characterized in this study by a real-time RT-PCR assay and/or sequencing of the hemagglutinin (HA) gene. Results Co-circulation of both B lineages was observed each season, although in different proportions every year. Overall, viruses of B/Victoria and B/Yamagata lineages caused 53.3 and 46.7% of influenza B infections, respectively. A higher proportion of infections with both lineages was detected in children, and there was a declining frequency of B/Victoria detections with age. A mismatch between the vaccine and the predominant influenza B lineage occurred in eight out of thirteen influenza seasons under study. Considering the seasons when B accounted for > 20% of all laboratory-confirmed influenza cases, a mismatch was observed in four out of six seasons. Phylogenetic analysis of the HA1 domain confirmed the co-circulation of both lineages and revealed a mixed circulation of distinct evolutionary viral variants, with different levels of match to the vaccine strains. Conclusions This study contributes to the understanding of the circulation of influenza B viruses in Italy. We found a continuous co-circulation of both B lineages in the period 2004–2017, and determined that children were particularly vulnerable to Victoria-lineage influenza B virus infections. An influenza B lineage mismatch with the trivalent vaccine occurred in about two-thirds of cases.

scholarly journals Influenza B Virus NS1-Truncated Mutants: Live-Attenuated Vaccine Approach

2008 ◽  
Vol 82 (21) ◽  
pp. 10580-10590 ◽  
Author(s):  
Rong Hai ◽  
Luis Martínez-Sobrido ◽  
Kathryn A. Fraser ◽  
Juan Ayllon ◽  
Adolfo García-Sastre ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Type I ◽  
Live Attenuated Vaccine ◽  
Live Virus ◽  
B Virus

ABSTRACT Type B influenza viruses can cause substantial morbidity and mortality in the population, and vaccination remains by far the best means of protection against infections with these viruses. Here, we report the construction of mutant influenza B viruses for potential use as improved live-virus vaccine candidates. Employing reverse genetics, we altered the NS1 gene, which encodes a type I interferon (IFN) antagonist. The resulting NS1 mutant viruses induced IFN and, as a consequence, were found to be attenuated in vitro and in vivo. The absence of pathogenicity of the NS1 mutants in both BALB/c and C57BL/6 PKR−/− mice was confirmed. We also provide evidence that influenza B virus NS1 mutants induce a self-adjuvanted immune response and confer effective protection against challenge with both homologous and heterologous B virus strains in mice.

Treatment of Mannan-Enhanced Influenza B Virus Infections in Mice with Oseltamivir, Ribavirin and Viramidine

2004 ◽  
Vol 15 (5) ◽  
pp. 261-268 ◽  
Author(s):  
Donald F Smee ◽  
Miles K Wandersee ◽  
Min-Hui Wong ◽  
Kevin W Bailey ◽  
Robert W Sidwell
Keyword(s):  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
B Virus

scholarly journals THE INFLUENCE OF CORTISONE ON EXPERIMENTAL VIRAL INFECTION

1957 ◽  
Vol 106 (6) ◽  
pp. 863-881 ◽  
Author(s):  
Edwin D. Kilbourne ◽  
Keyword(s):  
Maximal Activity ◽  
Influenza B Virus ◽  
Influenza B ◽  
Infective Virus ◽  
Virus Infections ◽  
In Ovo ◽  
Inhibiting Effect ◽  
Highly Active ◽  
B Virus ◽  
Experimental Viral Infection

The interference with viral synthesis which is induced by large quantities of non-infective influenza B virus is inhibited or negated with small quantities of cortisone and other C-21 steroids. The specificity of this effect is attested by the inactivity of 11-alpha hydroxy epimers of highly active compounds. Maximal activity in negation of interference is associated with the presence of oxygen at the C-11 position of the steroid molecule. In view of the demonstration that negation of interference can occur, it is concluded that the phenomenon of multiplicity reactivation of non-infective virus is not primarily influenced by cortisone. Rather, it is suggested that the reactivation phenomenon is unmasked by cortisone through its inhibiting effect on the autointerference intrinsic in multiplicity infection. If it is accepted that influenza virus infections in ovo are self-limited in part by viral autointerference, present evidence is consistent with the view that negation of this autointerference is the mechanism by which cortisone induces definitively increased yields of virus.

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