RESUMO
Repeated annual influenza vaccinations have been associated with reduced vaccine-induced antibody responses. This prospective study aimed to explore the role of vaccine antigen-specific regulatory T (Treg) cells in antibody response to repeated annual influenza vaccination. We analyzed pre- and postvaccination hemagglutination inhibition (HI) titers, seroconversion rates, seroprotection rates, vaccine antigen hemagglutinin (HA)-specific Treg cells, and conventional T (Tconv) cells. We compared these parameters between vaccinees with or without vaccine-induced seroconversion. Our multivariate logistic regression revealed that prior vaccination was significantly associated with a decreased likelihood of achieving seroconversion for both H1N1(adjusted OR, 0.03; 95% CI, 0.01-0.13) and H3N2 (adjusted OR, 0.09; 95% CI, 0.03-0.30). Furthermore, individuals who received repeated vaccinations had significantly higher levels of pre-existing HA-specific Treg cells than those who did not. We also found that vaccine-induced fold-increases in HI titers and seroconversion were negatively correlated with pre-existing HA-specific Treg cells and positively correlated with the ratio of Tconv to Treg cells. Overall, our findings suggest that repeated annual influenza vaccination is associated with a lower vaccine-induced antibody response and a higher frequency of vaccine-specific Treg cells. However, a lower frequency of pre-existing Treg cells correlates with a higher postvaccination antibody response.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Humanos , Influenza Humana/prevenção & controle , Linfócitos T Reguladores , Formação de Anticorpos , Vírus da Influenza A Subtipo H3N2 , Estudos Prospectivos , Anticorpos Antivirais , Vacinação , Testes de Inibição da HemaglutinaçãoRESUMO
Incessant antigenic evolution enables the persistence and spread of influenza virus in the human population. As the principal target of the immune response, the hemagglutinin (HA) surface antigen on influenza viruses continuously acquires and replaces N-linked glycosylation sites to shield immunogenic protein epitopes using host-derived glycans. Anti-glycan antibodies, such as 2G12, target the HIV-1 envelope protein (Env), which is even more extensively glycosylated and contains under-processed oligomannose-type clusters on its dense glycan shield. Here, we illustrate that 2G12 can also neutralize human seasonal influenza A H3N2 viruses that have evolved to present similar oligomannose-type clusters on their HAs from around 20 years after the 1968 pandemic. Using structural biology and mass spectrometric approaches, we find that two N-glycosylation sites close to the receptor binding site (RBS) on influenza hemagglutinin represent the oligomannose cluster recognized by 2G12. One of these glycan sites is highly conserved in all human H3N2 strains and the other emerged during virus evolution. These two N-glycosylation sites have also become crucial for fitness of recent H3N2 strains. These findings shed light on the evolution of the glycan shield on influenza virus and suggest 2G12-like antibodies can potentially act as broad neutralizers to target human enveloped viruses.
Assuntos
Anticorpos Antivirais/imunologia , HIV-1/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Anticorpos Amplamente Neutralizantes , Reações Cruzadas , Infecções por HIV/imunologia , Humanos , Influenza Humana/imunologiaRESUMO
We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Quarentena , Taiwan/epidemiologia , Aerossóis e Gotículas RespiratóriosRESUMO
BACKGROUND: Influenza A virus infections occur in different species, causing mild-to-severe symptoms that lead to a heavy disease burden. H1N1, H1N2 and H3N2 are major subtypes of swine influenza A viruses in pigs and occasionally infect humans. METHODS: A case infected by novel influenza virus was found through laboratory surveillance system for influenza viruses. Clinical specimens were tested by virus culture and/or real-time RT-PCR. The virus was identified and characterized by gene sequencing and phylogenetic analysis. RESULTS: In 2021, for the first time in Taiwan, an influenza A(H1N2)v virus was isolated from a 5-year old girl who was suffering from fever, runny nose and cough. The isolated virus was designated A/Taiwan/1/2021(H1N2)v. Full-genome sequencing and phylogenetic analyses revealed that A/Taiwan/1/2021(H1N2)v is a novel reassortant virus containing hemagglutinin (HA) and neuraminidase (NA) gene segments derived from swine influenza A(H1N2) viruses that may have been circulating in Taiwan for decades, and the other 6 internal genes (PB2, PB2, PA, NP, M and NS) are from human A(H1N1)pdm09 viruses. CONCLUSION: Notably, the HA and NA genes of A/Taiwan/1/2021(H1N2)v separately belong to specific clades that are unique for Taiwanese swine and were proposed to be introduced from humans in different time periods. Bidirectional transmission between humans and swine contributes to influenza virus diversity and poses the next pandemic threat.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Infecções por Orthomyxoviridae , Doenças dos Suínos , Animais , Vírus de DNA , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/epidemiologia , Neuraminidase/genética , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Filogenia , Vírus Reordenados , SuínosRESUMO
BACKGROUND: The rapid identification and isolation of individuals infected with SARS-CoV-2 are fundamental countermeasures for the efficient control of the COVID-19 pandemic, which has affected millions of people around the world. Real-time RT-PCR is one of the most commonly applied reference methods for virus detection, and the use of pooled testing has been proposed as an effective way to increase the throughput of routine diagnostic tests. However, the clinical applicability of different types of real-time RT-PCR tests in a given group size remains inconclusive due to inconsistent regional disease prevalence and test demands. METHODS: In this study, the performance of one dual-target conventional and two point-of-care real-time RT-PCR tests in a 5-specimen pooled testing strategy for the detection of SARS-COV-2 was evaluated. RESULTS: We demonstrated the proof of concept that all of these real-time RT-PCR tests could feasibly detect SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens that contain viral RNA loads in the range of 3.48 × 105 to 3.42 × 102 copies/ml through pooled testing in a group size of 5 with overall positive percent agreement (pooling vs. individual testing) ranging from 100% to 93.75%. Furthermore, the two POC real-time RT-PCR tests exhibited comparable sensitivity to that of the dual-target conventional one when clinical specimens were tested individually. CONCLUSION: Our findings support the feasibility of using real-time RT-PCR tests developed as a variety of platforms in routine laboratory detection of suspected COVID-19 cases through a pooled testing strategy that is beneficial to increasing the daily diagnostic capacity.
Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Humanos , Pandemias , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Influenza vaccine manufacturers traditionally use egg-derived candidate vaccine viruses (CVVs) to produce high-yield influenza viruses for seasonal or pandemic vaccines; however, these egg-derived CVVs need an adaptation process for the virus to grow in mammalian cells. The low yields of cell-based manufacturing systems using egg-derived CVVs remain an unsolved issue. This study aimed to develop high-growth cell-derived CVVs for MDCK cell-based vaccine manufacturing platforms. METHODS: Four H7N9 CVVs were generated in characterized Vero and adherent MDCK (aMDCK) cells. Furthermore, reassortant viruses were amplified in adherent MDCK (aMDCK) cells with certification, and their growth characteristics were detected in aMDCK cells and new suspension MDCK (sMDCK) cells. Finally, the plaque-forming ability, biosafety, and immunogenicity of H7N9 reassortant viruses were evaluated. RESULTS: The HA titers of these CVVs produced in proprietary suspension MDCK (sMDCK) cells and chicken embryos were 2- to 8-fold higher than those in aMDCK cells. All H7N9 CVVs showed attenuated characteristics by trypsin-dependent plaque assay and chicken embryo lethality test. The alum-adjuvanted NHRI-RG5 (derived from the fifth wave H7N9 virus A/Guangdong/SP440/2017) vaccine had the highest immunogenicity and cross-reactivity among the four H7N9 CVVs. Finally, we found that AddaVax adjuvant improved the cross-reactivity of low pathogenic H7N9 virus against highly pathogenic H7N9 viruses. CONCLUSIONS: Our study indicates that cell-derived H7N9 CVVs possessed high growth rate in new sMDCK cells and low pathogenicity in chicken embryo, and that CVVs generated by this platform are also suitable for both cell- and egg-based prepandemic vaccine production.
Assuntos
Imunização , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/química , Influenza Humana/prevenção & controle , Vírus Reordenados/imunologia , Animais , Embrião de Galinha , Cães , Humanos , Subtipo H7N9 do Vírus da Influenza A/genética , Células Madin Darby de Rim Canino , Vírus Reordenados/genéticaRESUMO
BACKGROUND/PURPOSE: A swine-origin influenza A/H1N1 virus (termed A/H1N1pdm) caused a pandemic in 2009 and has continuously circulated in the human population. To investigate its possible ecological effects on circulating influenza strains, the seasonal patterns of influenza viruses and the respective age distribution of infected patients were studies. METHODS: The data obtained from national influenza surveillance systems in Taiwan from July 2009 to June 2018 were analyzed. RESULTS: The A/H1N1pdm and A/H3N2 strains usually caused a higher ratio of severe to mild cases than influenza B. New variants of A/H1N1pdm and A/H3N2 emerged accompanied by a large epidemic peak. However, the new influenza B variants intended to circulate for several seasons before causing a large epidemic. The major group of outpatients affected by A/H1N1pdm were aged 13-23 years in the pandemic wave, and the age range of infected individuals gradually shifted to 24-49 and 0-6 years across seasons; A/H1N1pdm-infected inpatients were aged 24-49 years in 2009-2011, and the age range gradually switched to older groups aged 50-65 and >65 years. Individuals aged 0-6 or 24-49 years accounted for the majority of A/H3N2-infected outpatients across seasons, whereas most of the inpatients affected by A/H3N2 were aged >65 years. CONCLUSION: Understanding the effects of new variants and changes in dominant circulating viral strains on the age distribution of the affected human population, disease severity and epidemic levels is useful for the establishment of fine-tuned strategies for further improvement of influenza control.
Assuntos
Influenza Humana/epidemiologia , Estações do Ano , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Variação Genética , Humanos , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Pandemias , Filogenia , Taiwan/epidemiologia , Adulto JovemRESUMO
Human infection by low-pathogenic avian influenza viruses of the H7N9 subtype was first reported in March 2013 in China. Subsequently, these viruses caused five outbreaks through September 2017. In the fifth outbreak, H7N9 virus possessing a multiple basic amino acid insertion in the cleavage site of hemagglutinin emerged and caused 4% of all human infections in that period. To date, H7N9 highly pathogenic avian influenza viruses (HPAIVs) have been isolated from poultry, mostly chickens, as well as the environment. To evaluate the relative infectivity of these viruses in poultry, chickens and ducks were subjected to experimental infection with two H7N9 HPAIVs isolated from humans, namely A/Guangdong/17SF003/2016 and A/Taiwan/1/2017. When chickens were inoculated with the HPAIVs at a dose of 106 50% egg infectious dose (EID50), all chickens died within 2-5 days after inoculation, and the viruses replicated in most of the internal organs examined. The 50% lethal doses of A/Guangdong/17SF003/2016 and A/Taiwan/1/2017 in chickens were calculated as 103.3 and 104.7 EID50, respectively. Conversely, none of the ducks inoculated with either virus displayed any clinical signs, and less-efficient virus replication and less shedding were observed in ducks compared to chickens. These findings indicate that chickens, but not ducks, are highly permissive hosts for emerging H7N9 HPAIVs.
Assuntos
Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Influenza Humana/virologia , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Galinhas , Patos , Humanos , Subtipo H7N9 do Vírus da Influenza A/classificação , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Filogenia , Homologia de Sequência de Aminoácidos , Proteínas Virais/química , Proteínas Virais/genética , VirulênciaRESUMO
BACKGROUND: Human infection with avian influenza A virus (H7N9) was first reported in China in March 2013. Since then, hundreds of cases have been confirmed showing severe symptoms with a high mortality rate. The virus was transmitted from avian species to humans and has spread to many neighboring areas, raising serious concerns over its pandemic potential. Towards containing the disease, the goal of this study is to prepare a virus-like particle (VLP) that consists of hemagglutinin (HA), neuraminidase (NA) and matrix protein 1 (M1) derived from the human isolate A/Taiwan/S02076/2013(H7N9) for potential vaccine development. RESULTS: Full length HA, NA, and M1 protein genes were cloned and expressed using a baculoviral expression system, and the VLPs were generated by co-infecting insect cells with three respective recombinant baculoviruses. Nanoparticle tracking analysis and transmission electron microscopy were applied to verify the VLPs' structure and antigenicity, and the multiplicity of infection of the recombinant baculoviruses was adjusted to achieve the highest hemagglutination activity. In animal experiments, BALB/c mice and specific-pathogen-free chickens receiving the VLP immunization showed elevated hemagglutination inhibition serum titer and antibodies against NA and M1 proteins. In addition, examination of cellular immunity showed the VLP-immunized mice and chickens exhibited an increased splenic antigen-specific cytokines production. CONCLUSIONS: The H7N9 VLPs possess desirable immunogenicity in vivo and may serve as a candidate for vaccine development against avian influenza A (H7N9) infection.
Assuntos
Antígenos Virais/imunologia , Galinhas/imunologia , Vírus da Influenza A/imunologia , Camundongos/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Animais , Antígenos Virais/genética , Feminino , Vírus da Influenza A/genética , Camundongos Endogâmicos BALB C , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Especificidade da Espécie , Vacinas de Partículas Semelhantes a Vírus/genéticaRESUMO
We report a summer influenza epidemic caused by co-circulation of multiple influenza A(H3N2) variants in clade 3C.2a. Compared with other clades, a putative clade 3C.2a.3a was more commonly isolated from severely ill patients; 3C.2a.4 was more commonly isolated in outbreak cases. Time from vaccination to illness onset was significantly shorter in severely ill patients infected with clade 3C.2a.3; characteristics and outcomes of patients infected with different clades were similar. No resistance to antiviral medications was found.
Assuntos
Epidemias , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/epidemiologia , Estações do Ano , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Lactente , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/diagnóstico , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/isolamento & purificação , Taiwan/epidemiologia , Adulto JovemRESUMO
In Taiwan, although the coverage rate of two doses of measles-containing vaccine has been maintained at over 95% since 2001, measles outbreaks occurred in 2002, 2009, and 2011. The present study reports that 43 cases were confirmed by laboratory testing in Taiwan in 2012-2014 and that adults have emerged as one of groups susceptible to measles virus (MV) infection, who may have discrepant humoral immune reactions--indicated by the level of IgM and IgG antibodies compared to a naïve, susceptible measles case. Thirty-seven of 43 cases confirmed by RT-PCR were further characterized by genotyping. In Taiwan, genotype H1 was the major strain in circulation prior to 2010, while D9 was the most frequently detected MV genotype between 2010 and 2011. The genotyping data collected between 2012 and 2014 revealed that H1 rebounded in 2012 after an absence in 2011 and was imported from China and Vietnam. In 2014, genotype B3 first appeared in Taiwan following import from the Philippines and became the most frequently detected strain. Genotype D8, linked to importation from various countries, including India, Indonesia, Thailand, and Vietnam, showed sequence divergence. D9 was imported from Malaysia in 2014. The MV genotypes detected in Taiwan reflected the genotypes of circulating endemic measles strains in neighboring countries. A significant rise in the number of measles cases and in measles with genotypes imported from surrounding countries indicated that measles resurged in Asia in 2014.
Assuntos
Genótipo , Sarampo/epidemiologia , Sarampo/imunologia , Morbillivirus/classificação , Morbillivirus/genética , Adulto , Anticorpos Antivirais/sangue , Pré-Escolar , Monitoramento Epidemiológico , Feminino , Variação Genética , Técnicas de Genotipagem , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Masculino , Sarampo/virologia , Pessoa de Meia-Idade , Epidemiologia Molecular , Morbillivirus/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taiwan/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Patients contracting influenza A(H7N9) infection often developed severe disease causing respiratory failure. Neuraminidase (NA) inhibitors (NAIs) are the primary option for treatment, but information on drug-resistance markers for influenza A(H7N9) is limited. METHODS: Four NA variants of A/Taiwan/1/2013(H7N9) virus containing a single substitution (NA-E119V, NA-I222K, NA-I222R, or NA-R292K) recovered from an oseltamivir-treated patient were tested for NAI susceptibility in vitro; their replicative fitness was evaluated in cell culture, mice, and ferrets. RESULTS: NA-R292K led to highly reduced inhibition by oseltamivir and peramivir, while NA-E119V, NA-I222K, and NA-I222R caused reduced inhibition by oseltamivir. Mice infected with any virus showed severe clinical signs with high mortality rates. NA-I222K virus was the most virulent in mice, whereas virus lacking NA change (NA-WT) and NA-R292K virus seemed the least virulent. Sequence analysis suggests that PB2-S714N increased virulence of NA-I222K virus in mice; NS1-K126R, alone or in combination with PB2-V227M, produced contrasting effects in NA-WT and NA-R292K viruses. In ferrets, all viruses replicated to high titers in the upper respiratory tract but produced only mild illness. NA-R292K virus, showed reduced replicative fitness in this animal model. CONCLUSIONS: Our data highlight challenges in assessment of the replicative fitness of H7N9 NA variants that emerged in NAI-treated patients.
Assuntos
Antivirais/uso terapêutico , Farmacorresistência Viral , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Oseltamivir/uso terapêutico , Animais , Modelos Animais de Doenças , Furões , Humanos , Subtipo H7N9 do Vírus da Influenza A/enzimologia , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Proteínas Mutantes/genética , Mutação de Sentido Incorreto , Neuraminidase/genética , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Proteínas Virais/genética , Cultura de Vírus , Replicação ViralRESUMO
Six persons in Taiwan who had contact with poultry infected with influenza A(H5N2) showed seroconversion for the virus by hemagglutinin inhibition or microneutralization testing. We developed an ELISA based on nonstructural protein 1 of the virus to differentiate natural infection from cross-reactivity after vaccination; 2 persons also showed seroconversion by this test.
Assuntos
Anticorpos Antivirais/imunologia , Vírus da Influenza A Subtipo H5N2/imunologia , Influenza Humana/imunologia , Animais , Anticorpos Antivirais/sangue , Galinhas , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Humanos , Influenza Aviária/virologia , Influenza Humana/transmissão , Aves Domésticas , Doenças das Aves Domésticas/virologia , Taiwan , Proteínas não Estruturais Virais/imunologiaRESUMO
We report 2 cases of neonatal Legionella infection associated with aspiration of contaminated water used in hospitals to make infant formula. The molecular profiles of Legionella strains isolated from samples from the infants and from water dispensers were indistinguishable. Our report highlights the need to consider nosocomial legionellosis among neonates who have respiratory symptoms.
Assuntos
Infecção Hospitalar , Fórmulas Infantis , Legionella/isolamento & purificação , Legionelose/diagnóstico , Legionelose/microbiologia , Microbiologia da Água , Humanos , Recém-Nascido , Legionella/classificação , Legionella/genética , Legionelose/epidemiologia , Masculino , Vigilância da População , Taiwan/epidemiologiaRESUMO
New variants of the influenza A(H1N1)pdm09 and A(H3N2) viruses were detected in Taiwan between 2012 and 2013. Some of these variants were not detected in clinical specimens using a common real-time reverse transcription-PCR (RT-PCR) assay that targeted the conserved regions of the viral matrix (M) genes. An analysis of the M gene sequences of the new variants revealed that several newly emerging mutations were located in the regions where the primers or probes of the real-time RT-PCR assay bind; these included three mutations (G225A, T228C, and G238A) in the A(H1N1)pdm09 virus, as well as one mutation (C163T) in the A(H3N2) virus. These accumulated mismatch mutations, together with the previously identified C154T mutation of the A(H1N1)pdm09 virus and the C153T and G189T mutations of the A(H3N2) virus, result in a reduced detection sensitivity for the real-time RT-PCR assay. To overcome the loss of assay sensitivity due to mismatch mutations, we established a real-time RT-PCR assay using degenerate nucleotide bases in both the primers and probe and successfully increased the sensitivity of the assay to detect circulating variants of the human influenza A viruses. Our observations highlight the importance of the simultaneous use of different gene-targeting real-time RT-PCR assays for the clinical diagnosis of influenza.
Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/diagnóstico , Mutação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas da Matriz Viral/genética , Pareamento Incorreto de Bases , Primers do DNA/genética , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/virologia , Técnicas de Diagnóstico Molecular/métodos , Dados de Sequência Molecular , Proteínas Mutantes/genética , Sondas de Oligonucleotídeos/genética , RNA Viral/genética , Sensibilidade e Especificidade , Análise de Sequência de DNA , TaiwanRESUMO
BACKGROUND: World Health Organization (WHO) has recommended individuals with increased risk of contracting influenza A H5N1 infection to be immunized against the virus during the inter-pandemic period. Safety and immunogenicity of H5N1 vaccine among participants primed with homologous or heterologous H5N1 vaccines produced by diverse manufactures have not been reported. METHODS: Healthy individuals aged 20 to 60 years old were recruited and stratified into three groups: participants without priming (control group), participants primed with A/Indonesia/05/2005 vaccine, participants primed with A/Vietnam/1194/2004 vaccine and A/Indonesia/05/2005 vaccine. Enrolled participants received two doses of MF59-adjuvanted A/Vietnam/1194/2004 vaccine (study vaccine). Solicited reactions were recorded by vaccine recipients. Blood samples were obtained for hemagglutination inhibition test. RESULTS: A total of 131 participants were enrolled. No significant adverse events were recorded. Tenderness, fatigue and general muscle ache were the most common solicited reactions which alleviated within one week of immunization. Three weeks after two doses of the study vaccine, 63%, 68% and 88% were in seroprotective status in the control group, A/Indonesia/05/2005 primed group and A/Vietnam/1194/2004 and A/Indonesia/05/2005 primed group, respectively. Participants primed with A/Vietnam/1194/2004 and A/Indonesia/05/2005 showed high immune response after booster with one dose of the study vaccine. CONCLUSION: The study vaccine did not cause severe adverse events. It elicited mostly mild to moderate reactions among participants. Participants primed with A/Vietnam/1194/2004 and A/Indonesia/05/2005 vaccine showed higher immune response than those without priming or primed with A/Indonesia/05/2005 vaccine. The report suggested those with an increased risk of influenza A H5N1 virus exposure may benefit from receiving influenza A H5N1 priming during the inter-pandemic period if the antigenicity of the pandemic influenza strain is similar to that of the priming strain.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Polissorbatos/uso terapêutico , Esqualeno/uso terapêutico , Adulto , Anticorpos Antivirais/sangue , Formação de Anticorpos , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Imunização Secundária , Vacinas contra Influenza/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Esqualeno/imunologia , Vacinação , Vietnã , Organização Mundial da Saúde , Adulto JovemRESUMO
BACKGROUND: The cutaneous manifestations of human enterovirus (HEV) infection are usually limited, such as hand-foot-mouth disease. By comparison, Stevens-Johnson syndrome (SJS) is a life-threatening severe cutaneous adverse reaction (SCAR), mainly caused by drugs. During the HEV outbreaks in 2010-2012 in Taiwan, we identified 21 patients who developed widespread blistering mucocutaneous reactions without any suspected drug causality. METHODS: We screened possible pathogen(s) for detecting human herpes virus (HHV1-HHV7), HEV, or Mycoplasma pneumoniae infections using throat swab virus cultures, real-time PCR, DNA sequencing, immunochemistry and electron microscopy analyses. RESULTS: Coxsackievirus A6 (CVA6) DNA was identified in the blistering skin lesions in 6 of 21 patients. Cytotoxic T lymphocytes and natural killer cells expressing granulysin predominantly infiltrated into the skin lesions, sharing the histopathological features with SJS. Intact CVA6 viral particles were identified in the blister fluids and skin lesions by electron microscopy. The phylogenetic analysis of the viral genome showed the CVA6 DNA sequence sharing higher similarity (97.6%-98.1%) to CVA6 strains reported from Finland at 2008. CONCLUSIONS: This study identifies a new variant of CVA6 as the causative agent for severe mucocutaneous blistering reactions mimicking SCAR. An awareness of this unusual presentation of HEV infection is needed in the epidemic area.
Assuntos
Vesícula/virologia , Enterovirus/isolamento & purificação , Doença de Mão, Pé e Boca/virologia , Antígenos de Diferenciação de Linfócitos T/análise , Antígenos de Diferenciação de Linfócitos T/química , Biópsia , Vesícula/patologia , Líquidos Corporais/química , Líquidos Corporais/virologia , Criança , Pré-Escolar , DNA Viral/genética , DNA Viral/isolamento & purificação , Enterovirus/classificação , Enterovirus/genética , Feminino , Doença de Mão, Pé e Boca/patologia , Humanos , Células Matadoras Naturais , Masculino , Filogenia , Pele/química , Pele/patologia , Pele/virologia , Linfócitos T Citotóxicos , Vírion/genética , Vírion/isolamento & purificaçãoRESUMO
Mitigation measures aimed at curbing the transmission of the severe acute respiratory syndrome coronavirus 2 effectively suppressed the occurrence of many respiratory infections other than coronavirus disease 2019. Several infections experienced a resurgence following the relaxation of non-pharmaceutical interventions, surpassing pre-pandemic levels in Taiwan. This phenomenon, known as immune debt, primarily affected respiratory infections in young children, including respiratory syncytial virus (RSV) infection. Infections transmitted by means other than droplets or contact did not exhibit significant changes in their epidemic patterns, such as varicella and Japanese encephalitis. Alterations in seasonality were noted for RSV infection and influenza, and these changes are also linked to immune debt. The recent emergence of severe pediatric pneumonia in northern China may be associated with immune debt and the rise of macrolide-resistant Mycoplasma pneumoniae associated with severe illness.
RESUMO
We investigated a COVID-19 cluster involved seven case-patients lived in a high-rise building in September 2021. We used a simplified tracer-gas experiment and virus sequencing to establish the link between case-patients. Vertical transmission among vertically aligned apartments on different floors in a building was the most likely route of transmission.
Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Taiwan/epidemiologia , Transmissão Vertical de Doenças InfecciosasRESUMO
Rubella has been listed as a mandatory notifiable disease in Taiwan since 1988. Because of high coverage rates with an effective vaccine, rubella cases have decreased dramatically in Taiwan since 1994. However, rubella outbreaks still occur due to imported transmission. Five large clusters were detected in Taiwan from 2007 to 2011. In 2007, one cluster was caused by rubella genotype 1E viruses that were imported from Vietnam, whereas another cluster was caused by genotype 2B viruses and was untraceable. In 2008, two clusters were caused by different lineages of genotype 1E viruses that were imported from Malaysia. In 2009, a cluster that was caused by genotype 2B viruses was associated with imported cases from Vietnam. The rubella viruses from 124 confirmed cases from 2005 to 2011 were characterized, and the data revealed that these viruses were distributed in the following four genotypes: 1E (n = 56), 1h (n = 1), 1j (n = 4), and 2B (n = 63). Of these viruses, 93 (75%) were associated with imported cases, and 43 of 56 genotype 1E viruses were associated with imported cases from China, Vietnam, Malaysia, and Indonesia. One genotype 1h virus was imported from Belarus, and three of four genotype 1j viruses were imported from the Philippines. Of 63 rubella genotype 2B viruses, 46 were imported from Vietnam, Thailand, Malaysia, China, Germany, and South Africa. Molecular surveillance allows for the differentiation of circulating rubella viruses and can be used to investigate transmission pathways, which are important to identify the interruption of endemic virus transmission.