scholarly journals DISRUPTION OF INFLUENZA VIRUS

1954 ◽  
Vol 99 (4) ◽  
pp. 321-342 ◽  
Author(s):  
David A. J. Tyrrell ◽  
Frank L. Horsfall
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Infective Virus ◽  
Freezing And Thawing ◽  
Virus Particles ◽  
Homologous Virus ◽  
Repeated Freezing ◽  
Antigen Activity

1. The hemagglutinating capacity, enzymic activity, and infectivity of several influenza viruses were destroyed by repeated freezing and thawing of dialyzed allantoic fluids containing them. 2. Influenza virus degraded by freezing and thawing, by treatment with 5 M urea, or by heating at 65°C. still combined with homologous antibody and was demonstrable by blocking of the hemagglutination-inhibition and virus neutralization reactions. 3. After 50 cycles of freezing and thawing, much of the blocking antigen activity was not sedimented by centrifugation at 120,000 g for 2 hours, and electron microscopy showed complete disruption of the virus particles. So called soluble blocking antigen was obtained from four strains of influenza A, the Lee strain of influenza B, mumps, and Newcastle disease viruses. 4. Soluble blocking antigens from influenza A viruses were highly strain-specific; gave little or no reaction in complement-fixation tests; stimulated but little antibody production in rabbits and did not induce immunity in mice; caused reactivation of infective virus in neutral mixtures of homologous virus and immune serum. 5. Repeatedly frozen and thawed influenza virus preparations did not interfere with the propagation of infective virus in the allantoic sac. The blocking antigen activity they contained was precipitated by half saturated ammonium sulfate, destroyed by trypsin, chymotrypsin, or heating at 56°C. for 30 minutes, but was unaffected by desoxyribonuclease or ribonuclease. 6. These findings are in accord with the view that soluble blocking antigen obtained from influenza virus particles on disruption by repeated freezing and thawing is protein in nature and represents the essential antigenic material of the intact virus.

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 Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera

1978 ◽  
Vol 80 (1) ◽  
pp. 13-19 ◽  
Author(s):  
N. Masurel ◽  
J. I. de Bruijne ◽  
H. A. Beuningh ◽  
H. J. A. Schouten
Keyword(s):  
Influenza Virus ◽  
Maternal Age ◽  
Influenza A ◽  
Haemagglutination Inhibition ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
B Virus ◽  
Duration Of Pregnancy ◽  
Pregnancy And Birth

SUMMARYHaemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970–1.A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests.It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.

scholarly journals Detection of severe acute respiratory syndrome coronavirus 2 and influenza viruses based on CRISPR-Cas12a

2020 ◽  
pp. 153537022096379
Author(s):  
Oraphan Mayuramart ◽  
Pattaraporn Nimsamer ◽  
Somruthai Rattanaburi ◽  
Naphat Chantaravisoot ◽  
Kritsada Khongnomnan ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Severe Acute Respiratory Syndrome ◽  
Influenza A ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza Virus A ◽  
B Virus

Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

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.

scholarly journals Bacterial Sinusitis and Otitis Media following Influenza Virus Infection in Ferrets

2006 ◽  
Vol 74 (5) ◽  
pp. 2562-2567 ◽  
Author(s):  
Ville T. Peltola ◽  
Kelli L. Boyd ◽  
Julie L. McAuley ◽  
Jerold E. Rehg ◽  
Jonathan A. McCullers
Keyword(s):  
Influenza Virus ◽  
Otitis Media ◽  
Influenza A ◽  
Bacterial Colonization ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Complication Rates ◽  
Pneumococcal Infections

ABSTRACT Streptococcus pneumoniae is the leading cause of otitis media, sinusitis, and pneumonia. Many of these infections result from antecedent influenza virus infections. In this study we sought to determine whether the frequency and character of secondary pneumococcal infections differed depending on the strain of influenza virus that preceded bacterial challenge. In young ferrets infected with influenza virus and then challenged with pneumococcus, influenza viruses of any subtype increased bacterial colonization of the nasopharynx. Nine out of 10 ferrets infected with H3N2 subtype influenza A viruses developed either sinusitis or otitis media, while only 1 out of 11 ferrets infected with either an H1N1 influenza A virus or an influenza B virus did so. These data may partially explain why bacterial complication rates are higher during seasons when H3N2 viruses predominate. This animal model will be useful for further study of the mechanisms that underlie viral-bacterial synergism.

scholarly journals Impact of oseltamivir treatment on influenza A and B dynamics in human volunteers

2020 ◽  
Author(s):  
Kyla L. Hooker ◽  
Vitaly V. Ganusov
Keyword(s):  
Clinical Trials ◽  
Influenza Virus ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Shedding ◽  
Viral Shedding ◽  
Human Volunteers ◽  
The Impact

AbstractInfluenza viruses infect millions of humans every year causing an estimated 400,000 deaths globally. Due to continuous virus evolution current vaccines provide only limited protection against the flu. Several antiviral drugs are available to treat influenza infection, and one of the most most commonly used drugs is oseltamivir (Tamiflu). While the mechanism of action of oseltamivir as a neuraminidase inhibitor is well understood, the impact of oseltamivir on influenza virus dynamics in humans has been controversial. Many clinical trials with oseltamivir have been done by pharmaceutical companies such as Roche but the results of these trials until recently have been reported as summary reports or papers. Typically, such reports included median virus shedding curves for placebo and drug-treated influenza virus infected volunteers often indicating high efficacy of the early treatment. However, median shedding curves may be not accurately representing drug impact in individual volunteers. Importantly, due to public pressure clinical trials data testing oseltamivir efficacy has been recently released in the form of redacted PDF documents. We digitized and re-analyzed experimental data on influenza virus shedding in human volunteers from three previously published trials: on influenza A (1 trial) or B viruses (2 trials). Given that not all volunteers exposed to influenza viruses actually start virus shedding we found that impact of oseltamivir on the virus shedding dynamics was dependent on i) selection of volunteers that were infected with the virus, and ii) the detection limit in the measurement assay; both of these details were not well articulated in the published studies. By assuming that any viral measurement is above the limit of detection we could match previously published data on median influenza A virus (flu A study) shedding but not on influenza B virus shedding (flu B study B) in human volunteers. Additional analyses confirmed that oseltamivir had an impact on the duration of shedding and overall shedding (defined as area under the curve) but this result was varied by the trial. Interestingly, treatment had no impact on the rates at which shedding increased or declined with time in individual volunteers. Additional analyses showed that oseltamivir impacted the kinetics of the start and end of viral shedding and in about 20-40% of volunteers treatment had no impact on viral shedding duration. Our results suggest an unusual impact of oseltamivir on influenza viruses shedding kinetics and caution about the use of published median data or data from a few individuals for inferences. Furthermore, we call for the need to publish raw data from critical clinical trials that can be then independently analyzed.

scholarly journals Cross-Reactive Neuraminidase-Inhibiting Antibodies Elicited by Immunization with Recombinant Neuraminidase Proteins of H5N1 and Pandemic H1N1 Influenza A Viruses

2015 ◽  
Vol 89 (14) ◽  
pp. 7224-7234 ◽  
Author(s):  
Wen-Chun Liu ◽  
Chia-Ying Lin ◽  
Yung-Ta Tsou ◽  
Jia-Tsrong Jan ◽  
Suh-Chin Wu
Keyword(s):  
Influenza Virus ◽  
Sialic Acid ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Expression System ◽  
Influenza Viruses ◽  
Pandemic H1n1 ◽  
Influenza A Viruses ◽  
Homologous Virus ◽  
Universal Influenza Vaccine

ABSTRACTNeuraminidase (NA), an influenza virus envelope glycoprotein, removes sialic acid from receptors for virus release from infected cells. For this study, we used a baculovirus-insect cell expression system to construct and purify recombinant NA (rNA) proteins of H5N1 (A/Vietnam/1203/2004) and pandemic H1N1 (pH1N1) (A/Texas/05/2009) influenza viruses. BALB/c mice immunized with these proteins had high titers of NA-specific IgG and NA-inhibiting (NI) antibodies against H5N1, pH1N1, H3N2, and H7N9 viruses. H5N1 rNA immunization resulted in higher quantities of NA-specific antibody-secreting B cells against H5N1 and heterologous pH1N1 viruses in the spleen. H5N1 rNA and pH1N1 rNA immunizations both provided complete protection against homologous virus challenges, with H5N1 rNA immunization providing better protection against pH1N1 virus challenges. Cross-reactive NI antibodies were further dissected via pH1N1 rNA protein immunizations with I149V (NA with a change of Ile to Val at position 149), N344Y, and I365T/S366N NA mutations. The I365T/S366N mutation of pH1N1 rNA enhanced cross-reactive NI antibodies against H5N1, H3N2, and H7N9 viruses. It is our hope that these findings provide useful information for the development of an NA-based universal influenza vaccine.IMPORTANCENeuraminidase (NA) is an influenza virus enzymatic protein that cleaves sialic acid linkages on infected cell surfaces, thus facilitating viral release and contributing to viral transmission and mucus infection. In currently available inactivated or live, attenuated influenza vaccines based on the antigenic content of hemagglutinin proteins, vaccine efficacy can be contributed partly through NA-elicited immune responses. We investigated the NA immunity of different recombinant NA (rNA) proteins associated with pH1N1 and H5N1 viruses. Our results indicate that H5N1 rNA immunization induced more potent cross-protective immunity than pH1N1 rNA immunization, and three mutated residues, I149V, I365T, and S366N, near the NA enzyme active site(s) are linked to enhanced cross-reactive NA-inhibiting antibodies against heterologous and heterosubtypic influenza A viruses. These findings provide useful information for the development of an NA-based universal influenza vaccine.

scholarly journals Clinical Evaluation of the SD Bioline Influenza Virus Antigen Test for Rapid Detection of Influenza Viruses A and B in Children and Adults during the Influenza Season

2007 ◽  
Vol 14 (8) ◽  
pp. 1050-1052 ◽  
Author(s):  
Young Yoo ◽  
Jang Wook Sohn ◽  
Dae Won Park ◽  
Jeong Yeon Kim ◽  
Hye Kyung Shin ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Influenza Season ◽  
Virus Detection ◽  
Virus Antigen ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Antigen Test ◽  
Test Kit

ABSTRACT The performance of the SD Bioline rapid antigen test kit for influenza virus detection was evaluated with 295 respiratory specimens during the influenza season. The overall sensitivity and specificity of the SD Bioline test were 61.9% and 96.8% for the influenza A virus antigen and 54.5% and 100% for the influenza B virus antigen, respectively. The results were consistent with peak influenza activities.

scholarly journals Alternative Strategy for a Quadrivalent Live Attenuated Influenza Virus Vaccine

2018 ◽  
Vol 92 (21) ◽  
Author(s):  
Zhimin Wan ◽  
Stivalis Cardenas Garcia ◽  
Jing Liu ◽  
Jefferson Santos ◽  
Silvia Carnaccini ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza Virus Vaccine ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Influenza B ◽  
Lethal Challenge ◽  
B Virus ◽  
Live Attenuated Influenza Virus

ABSTRACT Influenza virus infections continue to pose a major public health threat worldwide associated with seasonal epidemics and sporadic pandemics. Vaccination is considered the first line of defense against influenza. Live attenuated influenza virus vaccines (LAIVs) may provide superior responses compared to inactivated vaccines because the former can better elicit a combination of humoral and cellular responses by mimicking a natural infection. Unfortunately, during the 2013–2014, 2014–2015, and 2015–2016 seasons, concerns emerged about the effectiveness of the only LAIV approved in the United States that prevented the Advisory Committee on Immunization Practices (ACIP) from recommending its use. Such drawbacks open up the opportunity for alternative LAIV strategies that could overcome such concerns. Previously, we developed a combined strategy of temperature-sensitive mutations in the PB2 and PB1 segments and an epitope tag in the C terminus of PB1 that effectively attenuates influenza A viruses of avian and mammalian origin. More recently, we adopted a similar strategy for influenza B viruses. The resulting attenuated (att) influenza A and B viruses were safe, immunogenic, and protective against lethal influenza virus challenge in a variety of animal models. In this report, we provide evidence of the potential use of our att strategy in a quadrivalent LAIV (QIV) formulation carrying H3N2 and H1N1 influenza A virus subtype viruses and two antigenic lineages of influenza B viruses. In naive DBA/2J mice, two doses of the QIV elicited hemagglutination inhibition (HI) responses with HI titers of ≥40 and effectively protected against lethal challenge with prototypical pandemic H1N1 influenza A and influenza B virus strains. IMPORTANCE Seasonal influenza viruses infect 1 billion people worldwide and are associated with ∼500,000 deaths annually. In addition, the never-ending emergence of zoonotic influenza viruses associated with lethal human infections and of pandemic concern calls for the development of better vaccines and/or vaccination strategies against influenza virus. Regardless of the strategy, novel influenza virus vaccines must aim at providing protection against both seasonal influenza A and B viruses. In this study, we tested an alternative quadrivalent live attenuated influenza virus vaccine (QIV) formulation whose individual components have been previously shown to provide protection. We demonstrate in proof-of principle studies in mice that the QIV provides effective protection against lethal challenge with either influenza A or B virus.

scholarly journals AMINO ACID COMPOSITION OF HIGHLY PURIFIED VIRAL PARTICLES OF INFLUENZA A AND B

1947 ◽  
Vol 86 (2) ◽  
pp. 125-129 ◽  
Author(s):  
C. A. Knight
Keyword(s):  
Amino Acids ◽  
Influenza Virus ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Isoleucine Leucine ◽  
Viral Particles ◽  
B Virus ◽  
Microbiological Assays

Microbiological assays for amino acids were made on hydrolysates of four to five highly purified preparations each of influenza A virus (PR8 strain) and influenza B virus (Lee strain). The results of the assays indicated that these strains of influenza virus contain approximately the same amounts of alanine, aspartic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, and valine. However, significant differences were found in the values for arginine, glutamic acid, lysine, tryptophane, and tyrosine. It is believed that these differences may provide, at least in part, a chemical explanation for some of the differing properties of the PR8 and Lee strains of influenza viruses.

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