Ian Barr

Ian Barr
Victorian Infectious Diseases Reference Laboratory | VIDRL · WHO Collaborating Centre for Reference and Research on Influenza

Doctor of Philosophy

About

301
Publications
63,248
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11,783
Citations
Citations since 2017
61 Research Items
5220 Citations
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Introduction
Skills and Expertise

Publications

Publications (301)
Article
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Prior vaccination can alternately enhance or attenuate influenza vaccine immunogenicity and effectiveness. Analogously, we found that vaccine immunogenicity was enhanced by prior A(H3N2) virus infection among participants of the Ha Nam Cohort, Viet Nam, but was attenuated by prior vaccination among Australian Health Care Workers (HCWs) vaccinated i...
Article
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Studies of successive vaccination suggest that immunological memory against past influenza viruses may limit responses to vaccines containing current strains. The impact of memory induced by prior infection is rarely considered and is difficult to ascertain, because infections are often subclinical. This study investigated influenza vaccination amo...
Preprint
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Annual epidemics of seasonal influenza cause hundreds of thousands of deaths, high levels of morbidity, and substantial economic loss. Yet, global influenza circulation has been heavily suppressed by public health measures and travel restrictions since the onset of the COVID-19 pandemic. Notably, the influenza B/Yamagata lineage has not been conclu...
Article
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The ferret is a key animal model for investigating the pathogenicity and transmissibility of important human viruses, and for the pre‐clinical assessment of vaccines. However, relatively little is known about the ferret immune system, due in part to a paucity of ferret‐reactive reagents. In particular, T follicular helper (Tfh) cells are critical i...
Article
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In 2009, a novel A(H1N1) influenza virus emerged with rapid human-to-human spread and caused the first pandemic of the 21st century. Although this pandemic was considered mild compared to the previous pandemics of the 20th century, there was still extensive disease and death. This virus replaced the previous A(H1N1) and continues to circulate today...
Article
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Influenza vaccination is recommended for children following allogeneic haematopoietic stem cell transplant (HSCT), however there is limited evidence regarding its benefit. A prospective multicentre study was conducted to evaluate the immunogenicity of the inactivated influenza vaccine in children who have undergone HSCT compared with healthy age-ma...
Article
Background: Seasonal influenza vaccination with a standard trivalent influenza vaccine (TIV) induces a modest, and cross-reactive, Fc functional antibody response in older adults. Recent improvements to influenza vaccines include a quadrivalent influenza vaccine (QIV) and a TIV adjuvanted with the squalene-based oil-in-water emulsion MF59. Method...
Article
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In Cambodia, highly pathogenic avian influenza A(H5N1) subtype viruses circulate endemically causing poultry outbreaks and zoonotic human cases. To investigate the genomic diversity and development of endemicity of the predominantly circulating clade 2.3.2.1c A(H5N1) viruses, we characterised 68 AIVs detected in poultry, the environment and from a...
Article
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Active surveillance in high-risk sites in Cambodia has identified multiple low-pathogenicity influenza A(H7) viruses, mainly in ducks. None fall within the A/Anhui/1/2013(H7N9) lineage; however, some A(H7) viruses from 2018 show temporal and phylogenetic similarity to the H7N4 virus that caused a nonfatal infection in Jiangsu Province, China, in De...
Article
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The anniversary of the 1918–1919 influenza pandemic has allowed a refocusing on the global burden of influenza and the importance of co-ordinated international surveillance for both seasonal influenza and the identification of control strategies for future pandemics. Since the introduction of the International Health Regulations (IHR), progress had...
Article
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Background Interseasonal influenza outbreaks are not unusual in countries with temperate climates and well-defined influenza seasons. Usually, these are small and diminish before the main influenza season begins. However, the 2018/19 summer-autumn interseasonal influenza period in Australia saw unprecedented large and widespread influenza outbreaks...
Article
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Background: Influenza virus circulation is monitored through the Cambodian influenza-like illness (ILI) sentinel surveillance system and isolates are characterized by the National Influenza Centre (NIC). Seasonal influenza circulation has previously been characterized by year-round activity and a peak during the rainy season (June-November). Obje...
Article
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Australia was previously believed to be free of enzootic swine influenza viruses due strict quarantine practices and use of biosecure breeding facilities. The first proven Australian outbreak of swine influenza occurred in Western Australian in 2012, revealing an unrecognized zoonotic risk, and a potential future pandemic threat. A public health in...
Article
The majority of influenza vaccines are produced in embryonated eggs, but mutations occur as human influenza A(H3N2) viruses adapt to grow in eggs. This can alter virus antigenicity. Wu et al. (2019) reveal that there are two mutually exclusive pathways for egg adaptation, which has potential implications for future egg-based influenza vaccines.
Article
The persistent circulation of avian influenza viruses (AIVs) is an ongoing problem for many countries in South East Asia, causing large economic losses to both the agricultural and health sectors. This review analyses AIV diversity, evolution and the risk of AIV emergence in humans in countries of the Greater Mekong Subregion (GMS): Cambodia, Laos,...
Article
The importance of antiviral CD8+ T cell recognition of alternative reading frame (ARF)-derived peptides is uncertain. In this study, we describe an epitope (NS1-ARF21-8) present in a predicted 14-residue peptide encoded by the +1 register of NS1 mRNA in the influenza A virus (IAV). NS1-ARF21-8 elicits a robust, highly functional CD8+ T cell respons...
Article
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Influenza A, B and C viruses (IAV, IBV and ICV, respectively) circulate globally and infect humans, with IAV and IBV causing the most severe disease. CD8+ T cells confer cross-protection against IAV strains, however the responses of CD8+ T cells to IBV and ICV are understudied. We investigated the breadth of CD8+ T cell cross-recognition and provid...
Article
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Abstract The 2017–2018 seasonal influenza epidemics were severe in the US and Australia where the A(H3N2) subtype viruses predominated. Although circulating A(H3N2) viruses did not differ antigenically from that recommended by the WHO for vaccine production, overall interim vaccine effectiveness estimates were below historic averages (33%) for A(H3...
Article
During 2016/2017, several antigenically and genetically distinct variant viruses of the influenza B/Victoria/2/87-lineage (B/Vic) viruses, which have either deletions or mutations in the haemagglutinin (HA) emerged and co-circulated with other influenza B viruses from both the B/Vic and B/Yamagata/16/88-lineages (B/Yam). In this study we developed...
Article
Background: Antibody titres and vaccine effectiveness decline within six months after influenza vaccination in older adults. Biannual vaccination may be necessary to provide year-round protection in the tropics where influenza circulates throughout the year. Methods: Tropical Influenza Control Strategies (TROPICS1) was a single-centre, 1:1 rando...
Article
Live bird market surveillance for avian influenza viruses in Cambodia in 2015 has led to the detection of two 7:1 reassortant influenza A(H5N1) clade 2.3.2.1c viruses. These reassortant strains, designated A/duck/Cambodia/Z564W35M1/2015 and A/chicken/Cambodia/Z850W49M1/2015, both contained a single gene (PB1 and matrix gene, respectively) from conc...
Article
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Global swine populations infected with influenza A viruses pose a persistent pandemic risk. With the exception of a few countries, our understanding of the genetic diversity of swine influenza viruses is limited, hampering control measures and pandemic risk assessment. Here we report the genomic characteristics and evolutionary history of influenza...
Article
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The ferret transmission model is extensively used to assess the pandemic potential of emerging influenza viruses, yet experimental conditions and reported results vary among laboratories. Such variation can be a critical consideration when contextualizing results from independent risk-assessment studies of novel and emerging influenza viruses. To s...
Article
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In January 2017, an estimated 3,700 (93%) of 4,000 Khaki Campbell ducks (Anas platyrhynchos domesticus) died in Kampong Thom Province, Cambodia. We detected low pathogenicity avian influenza A(H7N3) virus and anatid herpesvirus 1 (duck plague) in the affected flock; however, the exact cause of the mortality event remains unclear. © 2018, Centers fo...
Article
Live attenuated influenza vaccines (LAIVs) are promising tools for the induction of broad protection from influenza due to their ability to stimulate cross-reactive T cells against influenza pathogens. One of the major targets for cytotoxic T-cell immunity is viral nucleoprotein (NP), which is relatively conserved among antigenically distant influe...
Data
Specific primers used to amplify influenza A virus subtype H7N3 genes, GenBank accession numbers, and phylogenetic analysis of internal genes of H7N3 isolates, Cambodia.
Article
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Background Many serologic studies were done during and after the 2009 influenza pandemic, to estimate the cumulative incidence of influenza A(H1N1)pdm09 virus infections, but there are few comparative estimates of the incidence of influenza A(H3N2) virus infections during epidemics. Methods We conducted a longitudinal serologic study in Hong Kong....
Article
Epidemiological studies have observed that the seasonal peak incidence of influenza virus infection is sometimes separate from the peak incidence of human respiratory syncytial virus (hRSV) infection, with the peak incidence of hRSV infection delayed. This is proposed to be due to viral interference, whereby infection with one virus prevents or del...
Article
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Background: To inform national healthcare authorities whether quadrivalent influenza vaccines (QIVs) provide better value for money than trivalent influenza vaccines (TIVs), we assessed the cost-effectiveness of TIV and QIV in low-and-middle income communities based in South Africa and Vietnam and contrasted these findings with those from a high-i...
Article
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The factors that determine the pattern and rate of spread of influenza virus at a continental-scale are uncertain. Although recent work suggests that influenza epidemics in the United States exhibit a strong geographical correlation, the spatiotemporal dynamics of influenza in Australia, a country and continent of approximately similar size and cli...
Data
Summary of the data set. The number of laboratory-confirmed influenza cases in Australia, per day, from 1st January 2006 until 31st December 2016, showing (A) patient age ranges; and (B) the type/subtype of the virus detected. (TIF)
Data
The order of grey vertical bars in Fig 4 in the main text that mark the pairwise distances between the major cities. (DOCX)
Data
(A) The mean (and 95% confidence intervals) week of epidemic onset timing for influenza A (both subtypes and unsubtyped data) and B in Australia. (B) The mean (and 95% confidence intervals) week of epidemic onset timing for influenza A/H1N1, A/H3N2 and B. (TIF)
Data
Maximum likelihood phylogenetic trees of influenza virus, showing the two largest clades isolated from Australia that had specific sampling location available from each year shown in Fig 6 in the main text (A-B: A/H1N1 2009; C-D: A/H3N2 2014; E-F: influenza B 2015). HA genetic sequences were downloaded from the GISAID EpiFlu database (platform.gisa...
Article
Background: Two influenza B virus lineages, B/Victoria and B/Yamagata, cocirculate in the human population. While the lineages are serologically distinct, cross-reactive responses to both lineages have been detected. Viral interference describes the situation whereby infection with one virus limits infection and replication of a second virus. We i...
Article
The 2010 influenza season was moderate overall, with more laboratory-confirmed cases than in earlier years (with the exception of 2009). That said, self-reported influenza-like illness (ILI) was equal to or lower than 2008 and earlier years. In 2010, the number of laboratory-confirmed notifications for influenza was 0.8 times the 5-year mean. High...
Article
Small-animal models have been used to obtain many insights regarding the pathogenesis and immune responses induced following infection with human respiratory syncytial virus (hRSV). Among those described to date, infections in cotton rats, mice, guinea pigs, chinchillas, and Syrian hamsters with hRSV strains Long and/or A2 have been well characteri...
Article
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For over a decade virtually all A(H3N2) influenza viruses have been resistant to the adamantane class of antivirals. However, during the 2017 influenza season in Australia, 15/461 (3.3%) adamantane-sensitive A(H3N2) viruses encoding serine at residue 31 of the M2 protein were detected, more than the total number identified globally during the last...
Article
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Aim: Influenza control strategies focus on the use of trivalent influenza vaccines containing two influenza A virus subtypes and one of the two circulating influenza type B lineages (Yamagata or Victoria). Mismatches between the vaccine B lineage and the circulating lineage have been regularly documented in many countries, including those in the A...
Article
Background: The isolation and propagation of influenza viruses from clinical specimens are essential tools for comprehensive virologic surveillance. Influenza viruses must be amplified in cell culture for detailed antigenic analysis and for phenotypic assays assessing susceptibility to antiviral drugs or for other assays. Objectives: To conduct...
Article
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Background: Many health authorities recommend influenza vaccination of older adults to reduce disease burden. We hypothesized that in tropical and subtropical areas with more prolonged influenza seasons, twice-annual influenza vaccination might provide older adults with improved immunity against influenza. Methods: In 2014/15, Hong Kong experien...
Article
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Influenza A and B viruses are the causative agents of annual influenza epidemics that can be severe; influenza A viruses intermittently cause pandemics. Sequence information from influenza genomes is instrumental in determining mechanisms underpinning antigenic evolution and antiviral resistance. However, due to sequence diversity and the dynamics...
Article
Globally the most commonly utilised immunisation against influenza is the trivalent inactivated influenza vaccine (TIV) derived from an A/H1N1, an A/H3N2 and a. B type influenza virus. Vaccine effectiveness of TIV varies year to year, depending on how well antigenically matched the strains in the vaccine are compared to circulating strains [1,2]. M...
Article
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Background: After 2009, pandemic influenza A(H1N1) [A(H1N1)pdm09] cocirculated with A(H3N2) and B in Singapore. Methods: A cohort of 760 participants contributed demographic data and up to 4 blood samples each from October 2009 to September 2010. We compared epidemiology of the 3 subtypes and investigated evidence for heterotypic immunity throug...
Article
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Influenza A virus (IAV) PB1-F2 protein has been linked to viral virulence. Strains of the H3N2 subtype historically express full-length PB1-F2 proteins but during the 2010–2011 influenza seasons, nearly half of the circulating H3N2 IAVs encoded truncated PB1-F2 protein. Using a panel of reverse engineered H3N2 IAVs differing only in the origin of t...
Article
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Background Two subtypes of influenza A currently circulate in humans: seasonal H3N2 (sH3N2, emerged in 1968) and pandemic H1N1 (pH1N1, emerged in 2009). While the epidemiological characteristics of the initial wave of pH1N1 have been studied in detail, less is known about its infection dynamics during subsequent waves or its severity relative to sH...
Article
Highly pathogenic avian influenza viruses (HPAI) of the influenza A, H5N1 subtype (the H refers to the type of haemagglutinin and the N refers to the type of neuraminidase) have circulated in various parts of Asia since 1996, infecting millions of birds and, occasionally, humans [1, 2]. Since 2014, a subclade of these viruses has further reassorted...
Article
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Since 2010 the WHO has held a series of informal consultations to explore ways of improving the currently highly complex and time-pressured influenza vaccine virus selection and development process. In November 2015 experts from around the world met to review the current status of efforts in this field. Discussion topics included strengthening infl...
Article
Avian influenza normally has little impact on poultry and wild birds but since 1996, highly virulent viruses have emerged and continue to circulate in many countries. The results of these viruses have been devastating in domestic poultry and they have also spilled over into humans, infecting and killing hundreds and raising the opportunities for th...
Article
Importance: Analysis of avian influenza viruses (AIVs) detected in Antarctica reveals both the relatively recent introduction of an H5N5 AIV predominantly of North American-like origin, as well as the persistence of an evolutionarily divergent H11 AIV. These data demonstrate that the flow of viruses from North America may be more common than initi...
Article
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Background: Before pandemic H1N1 vaccines were available, the potential benefit of existing seasonal trivalent inactivated influenza vaccines (IIV3s) against influenza due to the 2009 pandemic H1N1 influenza strain was investigated, with conflicting results. This study assessed the efficacy of seasonal IIV3s against influenza due to 2008 and 2009...
Data
Data S1. Detailed methodology, additional results and sensitivity analyses. Table S1. Model parameters and main analysis scenario values. Table S2. Age‐specific health parameters. Table S3. ‐ Percentage of influenza B lineages and linage used in TIV. Table S4. Estimated influenza attack rates by community and vaccination scenario. Table S5. Es...
Article
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Background: Influenza C is usually considered a minor cause of respiratory illness in man with many infections being asymptomatic or clinically mild. Large outbreaks can occur periodically resulting in significant morbidity. Objectives: This study was aimed at analyzing the available influenza C clinical samples from two widely separated states...
Article
Influenza vaccines are usually non-adjuvanted but addition of adjuvant may improve immunogenicity and permit dose-sparing, critical for vaccine supply in the event of an influenza pandemic. The aim of this first-in-man study was to determine the effect of delta inulin adjuvant on the safety and immunogenicity of a reduced dose seasonal influenza va...
Article
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Background: Immunity to human influenza A virus (IAV) infection is only partially understood. Broadly non-neutralizing antibodies may assist in reducing disease but have not been well characterized. Methods: We measured internalization of opsonized, influenza protein-coated fluorescent beads and live IAV into a monocytic cell line to study antib...
Article
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The conserved internal influenza proteins nucleoprotein (NP) and matrix 1 (M1) are well characterised for T cell immunity, but whether they also elicit functional antibodies capable of activating natural killer (NK) cells has not been explored. We studied NP and M1-specific ADCC activity using biochemical, NK cell activation and killing assays with...
Article
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Influenza B viruses make up an important part of the burden from seasonal influenza globally. The 2015 sea-son in Australia saw an unusual predominance of influ-enza B with a distinctive switch during the season from B/Yamagata/16/88 lineage viruses to B/Victoria/2/87 lineage viruses. We also noted significant differences in the age groups infected...
Article
The WHO Collaborating Centre for Reference and Research on Influenza in Melbourne is part of the World Health Organization's (WHO) Global Influenza Surveillance and Response System. In 2014 the Centre received a total of 5,374 influenza samples from laboratories primarily in the Asia-Pacific region. Viruses were characterised by their antigenic, ge...
Article
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Importance: Both influenza A and B viruses co-circulate in the human population and annual influenza seasons are typically dominated by an influenza A subtype or an influenza B lineage. Surveillance data indicates that the burden of disease is higher in some seasons, yet it is unclear whether this is due to specific virus strains or to other facto...
Article
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Influenza is associated with significant morbidity and mortality in children receiving therapy for cancer, yet recommendation for, and uptake of the seasonal vaccine remains poor. One hundred children undergoing treatment for cancer were vaccinated with the trivalent inactivated influenza vaccine according to national guidelines in 2010 and 2011. I...
Data
Table S1. Classification of treatment according to intensity.