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1.
PLoS One ; 15(6): e0233632, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32492039

RESUMO

Increasing pandemic influenza vaccine manufacturing capacity is considered strategic by WHO. Adjuvant use is key in this strategy in order to spare the vaccine doses and by increasing immune protection. We describe here the production and stability studies of a squalene based oil-in-water emulsion, adjuvant IB160, and the immune response of the H7N9 vaccine combined with IB160. To qualify the production of IB160 we produced 10 consistency lots of IB160 and the average results were: pH 6.4±0.05; squalene 48.8±.0.03 mg/ml; osmolality 47.6±6.9 mmol/kg; Z-average 157±2 nm, with polydispersity index (PDI) of 0.085±0.024 and endotoxin levels <0.5 EU/mL. The emulsion particle size was stable for at least six months at 25°C and 24 months at 4-8°C. Two doses of H7N9 vaccine formulated at 7.5 µg/dose or 15 µg/dose with adjuvant IB160 showed a significant increase of hemagglutination inhibition (HAI) titers in sera of immunized BALB/c mice when compared to control sera from animals immunized with the H7N9 antigens without adjuvant. Thus the antigen-sparing capacity of IB160 can potentially increase the production of the H7N9 pandemic vaccine and represents an important achievement for preparedness against pandemic influenza and a successful North (IDRI) to South (Butantan Institute) technology transfer for the production of the adjuvant emulsion IB160.


Assuntos
Adjuvantes Farmacêuticos/síntese química , Emulsões/síntese química , Subtipo H7N9 do Vírus da Influenza A/imunologia , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Infecções por Orthomyxoviridae/prevenção & controle , Pandemias/prevenção & controle , Adjuvantes Farmacêuticos/química , Animais , Brasil/epidemiologia , Estabilidade de Medicamentos , Emulsões/química , Testes de Inibição da Hemaglutinação , Humanos , Vacinas contra Influenza/imunologia , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/virologia , Polissorbatos/química , Esqualeno/química , Transferência de Tecnologia , Vacinação/métodos
2.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(1): 69-74, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-32314726

RESUMO

Objective To prepare the monoclonal antibodies (mAb) against hemagglutinin of H4 subtype avian influenza virus (AIV), and develop a sandwich ELISA for the detection of H4 subtype AIV. Methods The BALB/c mice were immunized with inactive H4 subtype AIV. A mAb against H4 subtype AIV, designated as 6G4, was obtained by cell fusion, hemagglutination inhibition (HI) screening and subcloing. Immuofluorescence cytochemistry and Western blotting were used to detect the reactivity of 6G4 with H4 subtype AIV, and the specificity, broad spectrum and stability of 6G4 were characterized by HI assay. Subclass of 6G4 was determined by kit. With chicken polyclonal antibody against H4 subtype AIV as coated antibody, 6G4 mAb as capture antibody and HRP-labeled goat anti-mouse IgG as the enzyme-labeled antibody, a sandwich ELISA for the detection of H4 subtype AIV was established by optimization of the reaction conditions and serial verification. Results 6G4 belonged to IgG1 subclass, and the light chain belonged to κ. It could secrete antibody stably and had good reactivity, specificity, broad spectrum and stability. ELISA based on 6G4 was specific, sensitive, accurate and suitable for the detection of a large number of samples. Conclusion We successfully achieved the anti-H4 subtype AIV mAb, and developed the sandwich ELISA for the detection of H4 subtype AIV.


Assuntos
Anticorpos Monoclonais/biossíntese , Anticorpos Antivirais/biossíntese , Ensaio de Imunoadsorção Enzimática , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Testes de Inibição da Hemaglutinação , Vírus da Influenza A , Camundongos , Camundongos Endogâmicos BALB C
3.
J Vet Diagn Invest ; 32(3): 420-422, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32207372

RESUMO

The 2 predominant circulating subtypes of influenza A virus in the dog population, equine-origin H3N8 and avian-origin H3N2, constitute a potential zoonotic risk. We determined the prevalence of influenza A antibodies in 496 dogs in Poland and found 2.21% of sera positive by commercial ELISA. Hemagglutination inhibition (HI) assays indicated 7.25% of sera positive using equine H3N8, swine H3N2, and pandemic H1N1 antigens, with the most frequently detected immune response being to H3N2. Considering interspecies transfer, reassortment ability, and close contact between dogs and humans, infections of dogs with influenza A virus should be monitored.


Assuntos
Doenças do Cão/epidemiologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N8/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Animais , Doenças do Cão/virologia , Cães , Testes de Inibição da Hemaglutinação/veterinária , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Polônia/epidemiologia , Prevalência , Estudos Soroepidemiológicos
4.
Vet Microbiol ; 242: 108611, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122615

RESUMO

To improve the innate and adaptive immune responses elicited by a killed/inactivated swine influenza virus antigen (KAg)-loaded chitosan nanoparticles (CS NPs-KAg), we used the adjuvant, poly(I:C). The formulated CS NPs-KAg and CS NPs-poly(I:C) had a net surface charge of +30.7 mV and +25.1 mV, respectively. The CS NPs-KAg was coadministered with CS NPs-poly(I:C) (chitosan nanovaccine) as intranasal mist. Vaccinations enhanced homologous (H1N2-OH10) and heterologous (H1N1-OH7) hemagglutination inhibition (HI) titers in both vaccinated and virus-challenged animals compared to the control soluble poly(I:C) vaccinated pigs. In addition, the chitosan nanovaccine induced the proliferation of antigen-specific IFNγ secreting T-helper/memory and γδ T cells compared to control poly(I:C) group; and an increased Th1 (IFNγ, IL-6 and IL-2) and Th2 (IL-10 and IL-13) cytokines mRNA expression in the tracheobronchial lymph nodes compared to lymphoid tissues obtained from pigs given commercial influenza vaccine. The virus load in nasal passages and microscopic lung lesions were partially reduced by both chitosan nanovaccine and commercial vaccine. The HA gene homology between the vaccine and challenge viruses indicated that the chitosan nanovaccine induced a cross-protective immune response. In conclusion, coadministration of CS NPs-poly(I:C) with CS NPs-KAg augmented the cross-reactive specific HI titers and the cell-mediated immune responses in pigs.


Assuntos
Imunidade Celular , Vacinas contra Influenza/imunologia , Nanopartículas/administração & dosagem , Infecções por Orthomyxoviridae/prevenção & controle , Poli I-C/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Quitosana , Citocinas/genética , Citocinas/imunologia , Testes de Inibição da Hemaglutinação , Imunidade Inata , Vacinas contra Influenza/administração & dosagem , Poli I-C/imunologia , Suínos , Doenças dos Suínos/prevenção & controle , Células Th1/imunologia , Células Th2/imunologia , Carga Viral
5.
PLoS One ; 15(2): e0227719, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32012159

RESUMO

BACKGROUND: On-line hemodiafiltration (HDF) clears more azotemic toxins compared to high-flux hemodialysis (HD). The response to vaccination is impaired in dialysis patients. We wished to determine whether the immune responses to influenza vaccine in dialysis patients treated by HDF were stronger than those treated by HD. MATERIALS AND METHODS: We conducted a prospective cohort study in chronic dialysis patients during the 2016 and 2017 influenza seasons. All participants received a single standard dose of trivalent influenza vaccine, and we studied the elicited humoral immune response by hemagglutination inhibition test, and cell-mediated immune response by enumeration of lymphocyte cellular markers and proliferation assays. RESULTS: We immunized 60 end-stage renal disease (ESRD) patients: 42 (70%) treated with HD and 18 patients (30%) with HDF. The median (interquartile range) age was 65.0 (55.0-74.5) years. All patients developed seroprotection to at least one influenza vaccine strain at one month post-vaccination, and did not differ between groups. By logistic regression, age was the only factor independently associated with seroconversion to all vaccine strains (odds ratio 0.89, 95% confidence interval 0.80-0.98; p = 0.022). Seroprotection to all vaccine strains was sustained for longer in patients treated with HDF, and the results remained the same after age adjustment. For cellular immune response, patients who seroconverted to all vaccine strains had higher CD38+ T cell subpopulations pre-vaccination. Patients treated by HDF had higher lymphocyte proliferation to circulating influenza A strains. CONCLUSIONS: Seroconversion to all influenza vaccine strains was associated with age. Patients treated with HDF demonstrated seroprotection was sustained for longer compared to those treated by HD and greater lymphocyte proliferation to circulating influenza A strains. These encouraging results for HDF require confirmation in a larger dialysis population. TRIAL REGISTRATION: ClinicalTrial.gov, NCT04122222.


Assuntos
Imunidade Inata , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Falência Renal Crônica/prevenção & controle , Adulto , Idoso , Azotemia/imunologia , Azotemia/patologia , Proliferação de Células/genética , Feminino , Testes de Inibição da Hemaglutinação , Hemodiafiltração , Humanos , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/virologia , Falência Renal Crônica/imunologia , Falência Renal Crônica/virologia , Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Diálise Renal , Linfócitos T/imunologia , Vacinação , Vacinas/administração & dosagem
6.
mSphere ; 5(1)2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024713

RESUMO

While working overnight at a swine exhibition, we identified an influenza A virus (IAV) outbreak in swine, Nanopore sequenced 13 IAV genomes from samples we collected, and predicted in real time that these viruses posed a novel risk to humans due to genetic mismatches between the viruses and current prepandemic candidate vaccine viruses (CVVs). We developed and used a portable IAV sequencing and analysis platform called Mia (Mobile Influenza Analysis) to complete and characterize full-length consensus genomes approximately 18 h after unpacking the mobile lab. Exhibition swine are a known source for zoonotic transmission of IAV to humans and pose a potential pandemic risk. Genomic analyses of IAV in swine are critical to understanding this risk, the types of viruses circulating in swine, and whether current vaccines developed for use in humans would be predicted to provide immune protection. Nanopore sequencing technology has enabled genome sequencing in the field at the source of viral outbreaks or at the bedside or pen-side of infected humans and animals. The acquired data, however, have not yet demonstrated real-time, actionable public health responses. The Mia system rapidly identified three genetically distinct swine IAV lineages from three subtypes, A(H1N1), A(H3N2), and A(H1N2). Analysis of the hemagglutinin (HA) sequences of the A(H1N2) viruses identified >30 amino acid differences between the HA1 of these viruses and the most closely related CVV. As an exercise in pandemic preparedness, all sequences were emailed to CDC collaborators who initiated the development of a synthetically derived CVV.IMPORTANCE Swine are influenza virus reservoirs that have caused outbreaks and pandemics. Genomic characterization of these viruses enables pandemic risk assessment and vaccine comparisons, though this typically occurs after a novel swine virus jumps into humans. The greatest risk occurs where large groups of swine and humans comingle. At a large swine exhibition, we used Nanopore sequencing and on-site analytics to interpret 13 swine influenza virus genomes and identified an influenza virus cluster that was genetically highly varied to currently available vaccines. As part of the National Strategy for Pandemic Preparedness exercises, the sequences were emailed to colleagues at the CDC who initiated the development of a synthetically derived vaccine designed to match the viruses at the exhibition. Subsequently, this virus caused 14 infections in humans and was the dominant U.S. variant virus in 2018.


Assuntos
Genoma Viral , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H3N2/genética , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Monitoramento Epidemiológico , Variação Genética , Genótipo , Testes de Inibição da Hemaglutinação , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N2/classificação , Vírus da Influenza A Subtipo H3N2/classificação , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Filogenia , RNA Viral , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/transmissão , Estados Unidos/epidemiologia
7.
Influenza Other Respir Viruses ; 14(2): 210-214, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31856341

RESUMO

We measured antibodies against H7N9 virus 2 years after infection in 14 patients who were infected during October 2016-September 2017. Approximately 2 years after infection, antibody titers ≥10 were detectable in 13 (92.9%) patients. Three (21.4%) of 14 patients had hemagglutination inhibition titers ≥40, and their geometric mean titer (GMT) was 20 (95% CI 15.7-28.1), whereas 10 (71.4%) and all 14 (100%) of the 14 patients had titers ≥40, and GMTs at 34.4 (95% CI 25.7-51.2) and 73.45 (54.7-106.7) for neuraminidase inhibition and microneutralization antibodies, respectively. Our findings suggest that H7N9 infection may induce long-term antibody response at least 2 years after infection.


Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos , Subtipo H7N9 do Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Adulto , Idoso , Feminino , Seguimentos , Testes de Inibição da Hemaglutinação , Humanos , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade
8.
BMC Vet Res ; 15(1): 455, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31852473

RESUMO

BACKGROUND: The threat of poultry-origin H6 avian influenza viruses to human health emphasizes the importance of monitoring their evolution. South Africa's H6N2 epidemic in chickens began in 2001 and two co-circulating antigenic sub-lineages of H6N2 could be distinguished from the outset. The true incidence and prevalence of H6N2 in the country has been difficult to determine, partly due to the continued use of an inactivated whole virus H6N2 vaccine and the inability to distinguish vaccinated from non-vaccinated birds on serology tests. In the present study, the complete genomes of 12 H6N2 viruses isolated from various farming systems between September 2015 and February 2019 in three major chicken-producing regions were analysed and a serological experiment was used to demonstrate the effects of antigenic mismatch in diagnostic tests. RESULTS: Genetic drift in H6N2 continued and antigenic diversity in sub-lineage I is increasing; no sub-lineage II viruses were detected. Reassortment patterns indicated epidemiological connections between provinces as well as different farming systems, but there was no reassortment with wild bird or ostrich influenza viruses. The sequence mismatch between the official antigens used for routine hemagglutination inhibition (HI) testing and circulating field strains has increased steadily, and we demonstrated that H6N2 field infections are likely to be missed. More concerning, sub-lineage I H6N2 viruses acquired three of the nine HA mutations associated with human receptor-binding preference (A13S, V187D and A193N) since 2002. Most sub-lineage I viruses isolated since 2015 acquired the K702R mutation in PB2 associated with the ability to infect humans, whereas prior to 2015 most viruses in sub-lineages I and II contained the avian lysine marker. All strains had an unusual HA0 motif of PQVETRGIF or PQVGTRGIF. CONCLUSIONS: The H6N2 viruses in South African chickens are mutating and reassorting amongst themselves but have remained a genetically pure lineage since they emerged more than 18 years ago. Greater efforts must be made by government and industry in the continuous isolation and characterization of field strains for use as HI antigens, new vaccine seed strains and to monitor the zoonotic threat of H6N2 viruses.


Assuntos
Galinhas/virologia , Vírus da Influenza A/genética , Influenza Aviária/virologia , Animais , Deriva Genética , Genoma Viral , Testes de Inibição da Hemaglutinação/veterinária , Vírus da Influenza A/classificação , Vírus Reordenados/genética , Testes Sorológicos , África do Sul/epidemiologia , Vacinas de Produtos Inativados
9.
Viruses ; 12(1)2019 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-31878133

RESUMO

In order to assess influenza D virus (IDV) infections in swine in France, reference reagents were produced in specific pathogen free pigs to ensure serological and virological analyses. Hemagglutination inhibition (HI) assays were carried out on 2090 domestic pig sera collected in 2012-2018 in 102 farms. Only 31 sera from breeding sows sampled in 2014-2015 in six farrow-to-finish herds with respiratory disorders contained IDV-specific antibodies. In two of them, within-herd percentage of positive samples (73.3% and 13.3%, respectively) and HI titers (20-160) suggested IDV infections, but virus persistence was not confirmed following new sampling in 2017. All growing pigs tested seronegative, whatever their age and the sampling year. Moreover, PB1-gene RT-qPCR performed on 452 nasal swabs taken in 2015-2018 on pigs with acute respiratory syndrome (137 farms) gave negative results. In Corse, a Mediterranean island where pigs are mainly bred free-range, 2.3% of sera (n = 177) sampled on adult pigs in 2013-2014 obtained low HI titers. Finally, 0.5% of sera from wild boars hunted in 2009-2016 (n = 644) tested positive with low HI titers. These results provide the first serological evidence that sows were exposed to IDV in France but with a limited spread within the swine population.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Thogotovirus/imunologia , Animais , Cruzamento , Fazendas , Feminino , França/epidemiologia , Testes de Inibição da Hemaglutinação , Infecções por Orthomyxoviridae/epidemiologia , Organismos Livres de Patógenos Específicos , Sus scrofa/virologia , Suínos/virologia , Thogotovirus/genética
10.
Emerg Infect Dis ; 25(12): 2215-2225, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31742536

RESUMO

To determine the seroprevalence and seroconversion of avian influenza virus (AIV) antibodies in poultry workers, we conducted a seroepidemiologic study in 7 areas of China during December 2014-April 2016. We used viral isolation and reverse transcription PCR to detect AIVs in specimens from live poultry markets. We analyzed 2,124 serum samples obtained from 1,407 poultry workers by using hemagglutination inhibition and microneutralization assays. We noted seroprevalence of AIV antibodies for subtypes H9N2, H7N9, H6N1, H5N1-SC29, H5N6, H5N1-SH199, and H6N6. In serum from participants with longitudinal samples, we noted seroconversion, with >4-fold rise in titers, for H9N2, H7N9, H6N1, H5N1-SC29, H6N6, H5N6, and H5N1-SH199 subtypes. We found no evidence of H10N8 subtype. The distribution of AIV antibodies provided evidence of asymptomatic infection. We found that AIV antibody prevalence in live poultry markets correlated with increased risk for H7N9 and H9N2 infection among poultry workers.


Assuntos
Fazendeiros , Vírus da Influenza A , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Exposição Ocupacional/efeitos adversos , Adulto , Animais , Anticorpos Antivirais/sangue , China/epidemiologia , Feminino , Testes de Inibição da Hemaglutinação , História do Século XXI , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Influenza Humana/história , Influenza Humana/transmissão , Masculino , Pessoa de Meia-Idade , Aves Domésticas/virologia , Vigilância em Saúde Pública , Risco , Estudos Soroepidemiológicos , Sorogrupo
11.
Artigo em Inglês | MEDLINE | ID: mdl-31739554

RESUMO

The effects of immunization with subunit inactivated quadrivalent influenza vaccine (QIV) are not generally well assessed in the elderly Polish population. Therefore, this study evaluated vaccine-induced antibody response and its determinants. METHODS: Consecutive patients ≥ 55 years old, attending a Primary Care Clinic in Gryfino, Poland, received QIV (A/Michigan/ 45/2015(H1N1)pdm09, A/Singapore/INFIMH-16-0019/2016 (H3N2), B/Colorado/06/2017, B/Phuket/ 3073/2013) between October-December 2018. Hemagglutination inhibition assays measured antibody response to vaccine strains from pre/postvaccination serum samples. Geometric mean titer ratio (GMTR), protection rate (PR) and seroconversion rate (SR) were also calculated. RESULTS: For 108 patients (54.6% males, mean age: 66.7 years) the highest GMTR (61.5-fold) was observed for A/H3N2/, then B/Colorado/06/2017 (10.3-fold), A/H1N1/pdm09 (8.4-fold) and B/Phuket/ 3073/2013 (3.0-fold). Most patients had post-vaccination protection for A/H3N2/ and B/Phuket/3073/ 2013 (64.8% and 70.4%, respectively); lower PRs were observed for A/H1N1/pdm09 (41.8%) and B/Colorado/06/ 2017 (57.4%). The SRs for A/H3N2/, A/H1N1/pdm09, B Victoria and B Yamagata were 64.8%, 38.0%, 46.8%, and 48.2%, respectively. Patients who received QIV vaccination in the previous season presented lower (p < 0.001 and p = 0.03, respectively) response to B Victoria and B Yamagata. CONCLUSIONS: QIV was immunogenic against the additional B lineage strain (B Victoria) without significantly compromising the immunogenicity of the other three vaccine strains, therefore, adding a second B lineage strain in QIV could broaden protection against influenza B infection in this age group. As the QIV immunogenicity differed regarding the four antigens, formulation adjustments to increase the antigen concentration of the serotypes that have lower immunogenicity could increase effectiveness. Prior season vaccination was associated with lower antibody response to a new vaccine, although not consistent through the vaccine strains.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Subunidades/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Polônia
12.
J Vet Med Sci ; 81(11): 1597-1600, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31582645

RESUMO

Avian influenza (AI) is a disease caused by influenza viruses type A that belong to the Orthomyxoviridae family. AI induces high economic losses in poultry production worldwide. Due to a possible outbreak, a national surveillance program was needed. From April to July 2016, 152 industrial poultry farms were randomly sampled. All samples were analyzed by competitive ELISA for Influenza type A viruses. Suspicious and positive sera were further analyzed by Hemagglutination Inhibition (HI) in order to serotype H5 or H7 low pathogenic avian influenza virus (LPAIV). The farms sampled showed 94.08%, 3.95% and 1.97% of negative, positive and suspicious results, respectively. However, serotyping revealed all positive and suspicious samples were negative to H5/H7 LPAIV. Our results show the absence of AI in the mainland Ecuadorian industrial poultry production.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Estudos Transversais , Equador/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Testes de Inibição da Hemaglutinação/veterinária , Aves Domésticas , Doenças das Aves Domésticas/virologia , Estudos Soroepidemiológicos
13.
Influenza Other Respir Viruses ; 13(6): 622-626, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31478603

RESUMO

In late 2017, increased mortality was detected in chicken farms in Algeria undergoing A(H9N2) influenza outbreaks. Analysis of viruses isolated from affected farms showed that they were monophyletic, were of the G1 hemagglutinin (HA) lineage, and were antigenically and genetically similar to viruses detected contemporaneously in other countries in Northern Africa and the Middle East. The virus was able to spread via contact transmission between ferrets but did not cause disease in intravenously inoculated chickens.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Argélia/epidemiologia , Animais , Galinhas , Fazendas , Furões , Testes de Inibição da Hemaglutinação/veterinária , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/diagnóstico , Influenza Aviária/transmissão , Neuraminidase/genética , Filogenia , Carga Viral/veterinária , Proteínas Virais/genética
14.
Int J Infect Dis ; 89: 21-26, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31470089

RESUMO

BACKGROUND: We measured seroconversion to influenza viruses and incidence of symptomatic influenza virus infection in a cohort of children in Bangkok, Thailand. METHODS: Children aged ≤6 months were followed for two years for acute respiratory illness (ARI) and had serum specimens taken at 6-month intervals and tested by hemagglutination inhibition (HI) assay. Seroconversion was defined as a >4-fold rise in the HI titers between time points with a titer of >40 in the second specimen. Respiratory swabs were tested by rRT-PCR for influenza. Data were analyzed using generalized linear models. RESULTS: Of 350 children, 266 (76%, 147 were healthy and 119 were high-risk) had ≥2 serum specimens collected before influenza vaccination. During the 2-year follow-up, 266 children contributed 370 person-years of observation, excluding post-vaccination periods. We identified 32 ARI cases with rRT-PCR-confirmed influenza virus infection (7 infections/100 person-years, 95% confidence interval [CI], 4-11). There were 126 episodes of influenza virus infection, resulting in a seroconversion rate of 35 infections/100 person-years (95% CI, 30-42). Rates in healthy and high-risk children did not differ. CONCLUSIONS: Influenza virus infection is common during the first two years of life among Thai children. A large proportion of infections may not be detected using the ARI case definition.


Assuntos
Vírus da Influenza A/imunologia , Influenza Humana/epidemiologia , Vacinação , Pré-Escolar , Estudos de Coortes , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Incidência , Lactente , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Modelos Lineares , Masculino , Soroconversão , Tailândia/epidemiologia
15.
J Vet Med Sci ; 81(9): 1341-1347, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31341136

RESUMO

Influenza virus is known to affect wild felids. To explore the prevalence of influenza viruses in these animal species, 196 archival sera from 5 felid species including Panthera tigris (N=147), Prionailurus viverrinus (N=35), Panthera leo (N=5), Pardofelis temminckii (N=8) and Neofelis nebulosa (N=1) collected between 2011 and 2015 in 10 provinces of Thailand were determined for the presence of antibody to avian and human influenza viruses. Blocking enzyme-linked immunosorbent (ELISA) assay and hemagglutination inhibition (HI) assay were employed as the screening tests, which the serum samples with HI antibody titers ≥20 were further confirmed by cytopathic effect/hemagglutination based-microneutralization (CPE/HA-based microNT) test. Based on HI and microNT assays, the seropositive rates of low pathogenic avian influenza (LPAI) H5 virus, highly pathogenic avian influenza (HPAI) H5 virus and human H1 virus were 1.53% (3/196), 2.04% (4/196) and 6.63% (13/196), respectively. In addition, we also found antibody against both LPAI H5 virus and HPAI H5 virus in 2 out of 196 tested sera (1.02%). Evidences of influenza virus infection were found in captive P. tigris in Kanchanaburi, Nakhon Sawan and Ratchaburi provinces of Thailand. The findings of our study highlights the need of a continuous active surveillance program of influenza viruses in wild felid species.


Assuntos
Felidae/virologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Animais , Animais de Zoológico/virologia , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Testes de Inibição da Hemaglutinação/veterinária , Infecções por Orthomyxoviridae/epidemiologia , Prevalência , Estudos Soroepidemiológicos , Tailândia/epidemiologia
16.
Nat Commun ; 10(1): 3338, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31350391

RESUMO

Several vaccines are approved in the United States for seasonal influenza vaccination every year. Here we compare the impact of repeat influenza vaccination on hemagglutination inhibition (HI) titers, antibody binding and affinity maturation to individual hemagglutinin (HA) domains, HA1 and HA2, across vaccine platforms. Fold change in HI and antibody binding to HA1 trends higher for H1N1pdm09 and H3N2 but not against B strains in groups vaccinated with FluBlok compared with FluCelvax and Fluzone. Antibody-affinity maturation occurs against HA1 domain of H1N1pdm09, H3N2 and B following vaccination with all vaccine platforms, but not against H1N1pdm09-HA2. Importantly, prior year vaccination of subjects receiving repeat vaccinations demonstrated reduced antibody-affinity maturation to HA1 of all three influenza virus strains irrespective of the vaccine platform. This study identifies an important impact of repeat vaccination on antibody-affinity maturation following vaccination, which may contribute to lower vaccine effectiveness of seasonal influenza vaccines in humans.


Assuntos
Afinidade de Anticorpos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Feminino , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Vacinação , Adulto Jovem
17.
Hum Vaccin Immunother ; 15(9): 2030-2043, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291153

RESUMO

Pre-existing immunity to influenza is dependent on a number of factors and can vary greatly within and across influenza subtypes. In this study, volunteers (aged 18-85 years) were vaccinated with split, inactivated FluzoneTM in four consecutive influenza seasons from 2013 to 2016. The impact of repeat vaccination on breadth and durability of functional antibodies was assessed for total IgG and IgA anti-hemagglutinin (HA) binding antibodies and hemagglutination-inhibition (HAI) activity against both influenza B lineages. Many subjects were able to maintain high seroprotective titers to the vaccine strains in subsequent years, which resulted in low vaccine-induced seroconversion rates. This was especially evident in younger subjects who typically had higher titers and maintained these titers into the following season. In contrast, the HAI titers in elderly subjects were generally lower and more likely to decline prior to the start of the next influenza season. Immunological recall or 'back-boosting' to antigenically related viruses was associated with seroconversion. Overall, influenza vaccination in both younger and older people elicited broadly reactive immune responses within a lineage, as well as cross-reactive immune responses between lineages. This study exemplified the impact that age and influenza exposure history have on determining an individual's ability to respond to future influenza infections.


Assuntos
Fatores Etários , Anticorpos Antivirais/sangue , Memória Imunológica , Vírus da Influenza B/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Esquema de Medicação , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Soroconversão , Adulto Jovem
18.
Scand J Immunol ; 90(4): e12801, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31269273

RESUMO

Influenza virus is a major respiratory pathogen, and vaccination is the main method of prophylaxis. In 2012, the trivalent live attenuated influenza vaccine (LAIV) was licensed in Europe for use in children. Vaccine-induced antibodies directed against the main viral surface glycoproteins, haemagglutinin (HA) and neuraminidase (NA) play important roles in limiting virus infection. The objective of this study was to dissect the influenza-specific antibody responses in children and adults, and T cell responses in children induced after LAIV immunization to the A/H1N1 virus. Blood samples were collected pre- and at 28 and 56 days post-vaccination from 20 children and 20 adults. No increase in micro-neutralization (MN) antibodies against A/H1N1 was observed after vaccination. A/H1N1 stalk-specific neutralizing and NA-inhibiting (NI) antibodies were boosted in children after LAIV. Interferon γ-producing T cells increased significantly in children, and antibody-dependent cellular-mediated cytotoxic (ADCC) cell activity increased slightly in children after vaccination, although this change was not significant. The results indicate that the NI assay is more sensitive to qualitative changes in serum antibodies after LAIV. There was a considerable difference in the immune response in children and adults after vaccination, which may be related to priming and previous influenza history. Our findings warrant further studies for evaluating LAIV vaccination immunogenicity.


Assuntos
Vírus da Influenza A Subtipo H1N1/fisiologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Vacinas Atenuadas/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Imunidade Humoral , Masculino , Vacinação
19.
J Microbiol Immunol Infect ; 52(5): 685-692, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31255574

RESUMO

BACKGROUND: Development of an efficacious egg-free mock-up H5N1 vaccine is key to our preparedness against pandemic avian flu. METHODS: This is a single-center, randomized, observer-blinded phase I clinical trial evaluating the safety and immunogenicity of an alum-adjuvanted Madin-Darby canine kidney (MDCK)-derived inactivated whole-virion H5N1 influenza vaccine in healthy adults. Hemagglutination inhibition (HAI) and neutralizing antibody titers were measured using horse and turkey red blood cells (RBCs). RESULTS: Thirty-six adult subjects were randomized to receive two doses of 0.5 mL of the MDCK-derived H5N1 alum-adjuvanted vaccine containing 7.5, 15, or 30 µg of hemagglutinin (HA) 21 days apart. The candidate vaccine was well tolerated and safe across the three dosing groups. The most frequent adverse event was injection site pain (46.5%). Both HAI and neutralizing antibody titers increased after each vaccination in all three dosing groups. The best HAI responses, namely a seroconversion rate of 91.7% and a geometric mean ratio of 9.51 were achieved with the HA dose of 30 µg assayed using horse RBCs at day 42. HAI titers against H5N1 avian influenza virus was significantly higher when measured using horse RBCs compared with turkey RBCs. CONCLUSIONS: This Phase I trial showed the MDCK-derived H5N1 candidate vaccine is safe and immunogenic. The source of RBCs has a significant impact on the measurement of HAI titers (ClinicalTrials.gov number: NCT01675284.).


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Imunogenicidade da Vacina , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Segurança , Adjuvantes Imunológicos/efeitos adversos , Adulto , Compostos de Alumínio/administração & dosagem , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Aves , Cães , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/fisiopatologia , Feminino , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Cavalos , Humanos , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/efeitos adversos , Influenza Aviária , Injeções Intramusculares , Células Madin Darby de Rim Canino , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Soroconversão , Taiwan , Vacinação/efeitos adversos , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/efeitos adversos , Vacinas de Produtos Inativados/imunologia , Adulto Jovem
20.
PLoS One ; 14(7): e0220401, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31356626

RESUMO

The 2017-2018 influenza epidemic season in Russia was characterized by a relatively low morbidity and mortality. We evaluated herd immunity prior to the 2017-2018 influenza season in hemagglutination inhibition assay, and performed characterization of influenza viruses isolated from severe or fatal influenza cases and from influenza cases in people vaccinated in the fall of 2017. During the 2017-2018 epidemic season, 87 influenza A and B viruses were isolated and viruses of the 75 influenza cases, including selected viral isolates and viruses analyzed directly from the original clinical material, were genetically characterized. The analyzed A(H1N1)pdm09 viruses belonged to clade 6B.1, B/Yamagata-like viruses belonged to clade 3, and B/Victoria-like viruses belonged to clade 1A and they were antigenically similar to the corresponding vaccine strains. A(H3N2) viruses belonged to clade 3C.2a and were difficult to characterize antigenically and the analysis indicated antigenic differences from the corresponding egg-grown vaccine strain. The next generation sequencing revealed the presence of D222/G/N polymorphism in the hemagglutinin gene in 32% of the analyzed A(H1N1)pdm09 lethal cases. This study demonstrated the importance of monitoring D222G/N polymorphism, including detection of minor viral variants with the mutations, in the hemagglutinin gene of A(H1N1)pdm09 for epidemiological surveillance. One strain of influenza virus A(H1N1)pdm09 was resistant to oseltamivir and had the H275Y amino acid substitution in the NA protein. All other isolates were susceptible to NA inhibitors. Prior to the 2017-2018 epidemic season, 67.4 million people were vaccinated, which accounted for 46.6% of the country's population. Just before the epidemic season 33-47% and 24-30% of blood sera samples collected within the territory of Russia showed the presence of protective antibody titers against vaccine strains of influenza A and influenza B/Victoria-like, respectively. Mass vaccination of the population had evidently reduced the severity of the flu epidemic during the 2017-2018 influenza epidemic season in Russia.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza B/classificação , Influenza Humana/epidemiologia , Influenzavirus A/classificação , Adolescente , Adulto , Criança , Pré-Escolar , Farmacorresistência Viral , Epidemias , Monitoramento Epidemiológico , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Lactente , Recém-Nascido , Vírus da Influenza B/genética , Vírus da Influenza B/imunologia , Influenza Humana/virologia , Influenzavirus A/genética , Influenzavirus A/imunologia , Masculino , Pessoa de Meia-Idade , Filogenia , Polimorfismo Genético , RNA Viral/genética , Federação Russa/epidemiologia , Adulto Jovem
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