1
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Yang T, Tang L, Li P, Li B, Ye L, Zhou J. Effectiveness of inactivated influenza vaccine against laboratory-confirmed influenza among Chinese elderly: a test-negative design. BMC Geriatr 2024; 24:404. [PMID: 38714944 PMCID: PMC11077745 DOI: 10.1186/s12877-024-05003-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Evidence on the effectiveness of influenza vaccination in the elderly is limited, and results are controversial. There are also few reports from China. METHODS We conducted a test-negative case-control study design to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated visits among elderly (aged ≥ 60 years) across four influenza seasons in Ningbo, China, from 2018 to 19 to 2021-22. Influenza-positive cases and negative controls were randomly matched in a 1:1 ratio according to age, sex, hospital, and date of influenza testing. We used logistic regression models to compare vaccination odds ratios (ORs) in cases to controls. We calculated the VE as [100% × (1-adjusted OR)] and calculated the 95% confidence interval (CI) around the estimate. RESULTS A total of 30,630 elderly patients tested for influenza with virus nucleic acid or antigen during the study period. After exclusions, we included 1 825 influenza-positive cases and 1 825 influenza-negative controls. Overall, the adjusted VE for influenza-related visits was 63.5% (95% CI, 56.3-69.5%), but varied by season. Influenza VE was 59.8% (95% CI, 51.5-66.7%) for influenza A and 89.6% (95% CI, 77.1-95.3%) for influenza B. The VE for ages 60-69 and 70-79 was 65.2% (95% CI, 55.4-72.9%) and 69.8% (95% CI, 58.7-77.9%), respectively, but only 45.4% (95% CI, 6.2-68.2%) for ages 80 and over. CONCLUSIONS Standard-dose inactivated influenza vaccine has shown good protection in the elderly in China. However, protection may not be satisfactory in people aged 80 years and older.
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Affiliation(s)
- Tianchi Yang
- Institute of Immunization and Prevention, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang, China
| | - Ling Tang
- Ningbo Health Information Center, Ningbo, Zhejiang, China
| | - Pingping Li
- Jiangbei District Center for Disease Control and Prevention, Ningbo, Zhejiang, China
| | - Baojun Li
- Haishu District Center for Disease Control and Prevention, Ningbo, Zhejiang, China
| | - Lixia Ye
- Institute of Immunization and Prevention, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang, China.
| | - Jifang Zhou
- School of International Pharmaceutical Business, China Pharmaceutical University, Jiangsu, China.
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2
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Kang M, Zanin M, Wong SS. Subtype H3N2 Influenza A Viruses: An Unmet Challenge in the Western Pacific. Vaccines (Basel) 2022; 10:vaccines10010112. [PMID: 35062773 PMCID: PMC8778411 DOI: 10.3390/vaccines10010112] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/07/2022] [Accepted: 01/07/2022] [Indexed: 02/04/2023] Open
Abstract
Subtype H3N2 influenza A viruses (A(H3N2)) have been the dominant strain in some countries in the Western Pacific region since the 2009 influenza A(H1N1) pandemic. Vaccination is the most effective way to prevent influenza; however, low vaccine effectiveness has been reported in some influenza seasons, especially for A(H3N2). Antigenic mismatch introduced by egg-adaptation during vaccine production between the vaccine and circulating viral stains is one of the reasons for low vaccine effectiveness. Here we review the extent of this phenomenon, the underlying molecular mechanisms and discuss recent strategies to ameliorate this, including new vaccine platforms that may provide better protection and should be considered to reduce the impact of A(H3N2) in the Western Pacific region.
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Affiliation(s)
- Min Kang
- School of Public Health, Southern Medical University, Guangzhou 510515, China;
- Guangdong Center for Disease Control and Prevention, Guangzhou 511430, China
| | - Mark Zanin
- State Key Laboratory for Respiratory Diseases and National Clinical Research Centre for Respiratory Disease, Guangzhou Medical University, 195 Dongfengxi Road, Guangzhou 511436, China;
- School of Public Health, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong, China
| | - Sook-San Wong
- State Key Laboratory for Respiratory Diseases and National Clinical Research Centre for Respiratory Disease, Guangzhou Medical University, 195 Dongfengxi Road, Guangzhou 511436, China;
- School of Public Health, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong, China
- Correspondence: ; Tel.: +86-178-2584-6078
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3
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Dang TKNS, Rivero Cabrera R, Yeung KHT, van der Putten IM, Nelson EAS. Feasibility of age- and gestation-based routine universal influenza vaccines schedules for children aged 6 months - 2 years and pregnant women. Vaccine 2021; 39:6754-6761. [PMID: 34674893 DOI: 10.1016/j.vaccine.2021.09.076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Hong Kong's seasonal influenza schedule follows the World Health Organization's northern hemisphere vaccine composition recommendations but with year-round influenza activity there is the potential to implement routine age- and gestation-based schedules utilising both northern and southern hemisphere vaccines for children aged 6 months to 2 years and for pregnant women. This study assessed the potential feasibility of such schedules. METHODS A literature review was conducted and in-depth interviews with vaccine experts, policy makers and nurses were undertaken. RESULTS The following schedules were proposed and assessed for perceived feasibility: 1) a four-dose schedule in the first two years of life requiring an additional unscheduled clinic visit at 7 months; 2) a three-dose schedule excluding the 4-week booster after the first dose; 3) a two-dose schedule for pregnant women involving a dose at the booking visit and a dose with pertussis vaccine at 7 months gestation; and 4) a one-dose schedule at 7 months gestation. CONCLUSIONS Age- and gestation-based routine influenza vaccination schedules are theoretically feasible for both young children and pregnant women. The three-dose paediatric and one-dose obstetric schedules were assessed in interviews with vaccine experts, policy makers and nurses to be most acceptable. Further clinical studies are required to determine whether such schedules are non-inferior to current seasonal-based schedules in terms of vaccine effectiveness and vaccine uptake.
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Affiliation(s)
- T K N Sandra Dang
- CAPHRI, Care and Public Health Research Institute, Department of Health Services Research, Maastricht University, Maastricht, the Netherlands.
| | - Romén Rivero Cabrera
- CAPHRI, Care and Public Health Research Institute, Department of Health Services Research, Maastricht University, Maastricht, the Netherlands.
| | | | - Ingeborg M van der Putten
- CAPHRI, Care and Public Health Research Institute, Department of Health Services Research, Maastricht University, Maastricht, the Netherlands.
| | - E Anthony S Nelson
- Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong.
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4
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Chen ICM, Loh JP, Chuah CXP, Gao QHC, Sun Y, Ng SH, Koh WHV, Goh EH, Zhao X, Tambyah PA, Cook AR, Chng J, Pang J, Tan BH, Lee VJ. Evidence for Cross-Protection Against Subsequent Febrile Respiratory Illness Episodes From Prior Infections by Different Viruses Among Singapore Military Recruits 2009-2014. J Infect Dis 2020; 219:1913-1923. [PMID: 30722024 PMCID: PMC6534195 DOI: 10.1093/infdis/jiz046] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/27/2019] [Indexed: 12/22/2022] Open
Abstract
Background Few studies have evaluated the relative cross-protection conferred by infection with different groups of viruses through studies of sequential infections in humans. We investigated the presence of short-lived relative cross-protection conferred by specific prior viral infections against subsequent febrile respiratory illness (FRI). Methods Men enlisted in basic military training between December 2009 and December 2014 were recruited, with the first FRI as the study entry point. ResPlex II assays and real-time polymerase chain reaction assays were used to detect viral pathogens in nasal wash samples, and survival analyses were performed to determine whether infection with particular viruses conferred short-lived relative cross-protection against FRI. Results Prior infection with adenovirus (hazard ratio [HR], 0.24; 95% confidence interval [CI], .14–.44) or influenza virus (HR, 0.52; 95% CI, .38–.73) conferred relative protection against subsequent FRI episode. Results were statistically significant even after adjustment for the interval between enlistment and FRI (P < .001). Adenovirus-positive participants with FRI episodes tended to be protected against subsequent infection with adenovirus, coronavirus, enterovirus/rhinovirus, and influenza virus (P = .062–.093), while men with influenza virus–positive FRI episodes tended be protected against subsequent infection with adenovirus (P = .044) and influenza virus (P = .081). Conclusion Prior adenovirus or influenza virus infection conferred cross-protection against subsequent FRI episodes relative to prior infection due to other circulating viruses.
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Affiliation(s)
- I-Cheng Mark Chen
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore.,Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | | | - Cheryl X P Chuah
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | | | - Yinxiaohe Sun
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore.,Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | | | | | - Ee Hui Goh
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | - Xiahong Zhao
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | - Paul Anantharajah Tambyah
- Yong Loo Lin School of Medicine, National University of Singapore and National University Hospital System, Singapore
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | - Jeremiah Chng
- Biodefence Centre, Headquarters Medical Corps, Singapore Armed Forces, Singapore
| | - Junxiong Pang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore.,Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore
| | - Boon-Huan Tan
- DSO National Laboratories, Singapore.,Infection and Immunity, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Vernon J Lee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Hospital System, Singapore.,Biodefence Centre, Headquarters Medical Corps, Singapore Armed Forces, Singapore
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5
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Ivan FX, Zhou X, Lau SH, Rashid S, Teo JSM, Lee HK, Koay ES, Chan KP, Leo YS, Chen MIC, Kwoh CK, Chow VT. Molecular insights into evolution, mutations and receptor-binding specificity of influenza A and B viruses from outpatients and hospitalized patients in Singapore. Int J Infect Dis 2020; 90:84-96. [PMID: 31669593 DOI: 10.1016/j.ijid.2019.10.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND This study compared the genomes of influenza viruses that caused mild infections among outpatients and severe infections among hospitalized patients in Singapore, and characterized their molecular evolution and receptor-binding specificity. METHODS The complete genomes of influenza A/H1N1, A/H3N2 and B viruses that caused mild infections among outpatients and severe infections among inpatients in Singapore during 2012-2015 were sequenced and characterized. Using various bioinformatics approaches, we elucidated their evolutionary, mutational and structural patterns against the background of global and vaccine strains. RESULTS The phylogenetic trees of the 8 gene segments revealed that the outpatient and inpatient strains overlapped with representative global and vaccine strains. We observed a cluster of inpatients with A/H3N2 strains that were closely related to vaccine strain A/Texas/50/2012(H3N2). Several protein sites could accurately discriminate between outpatient versus inpatient strains, with site 221 in neuraminidase (NA) achieving the highest accuracy for A/H3N2. Interestingly, amino acid residues of inpatient but not outpatient isolates at those sites generally matched the corresponding residues in vaccine strains, except at site 145 of hemagglutinin (HA). This would be especially relevant for future surveillance of A/H3N2 strains in relation to their antigenicity and virulence. Furthermore, we observed a trend in which the HA proteins of influenza A/H3N2 and A/H1N1 exhibited enhanced ability to bind both avian and human host cell receptors. In contrast, the binding ability to each receptor was relatively stable for the HA of influenza B. CONCLUSIONS Overall, our findings extend our understanding of the molecular and structural evolution of influenza virus strains in Singapore within the global context of these dynamic viruses.
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Affiliation(s)
- Fransiskus X Ivan
- School of Computer Science and Engineering, Nanyang Technological University, Singapore
| | - Xinrui Zhou
- School of Computer Science and Engineering, Nanyang Technological University, Singapore
| | - Suk Hiang Lau
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shamima Rashid
- School of Computer Science and Engineering, Nanyang Technological University, Singapore
| | - Jasmine S M Teo
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hong Kai Lee
- Molecular Diagnosis Centre, National University Hospital, Singapore; Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Evelyn S Koay
- Molecular Diagnosis Centre, National University Hospital, Singapore; Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kwai Peng Chan
- Department of Pathology, Singapore General Hospital, Singapore
| | - Yee Sin Leo
- National Centre for Infectious Diseases, Singapore
| | - Mark I C Chen
- National Centre for Infectious Diseases, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Chee Keong Kwoh
- School of Computer Science and Engineering, Nanyang Technological University, Singapore.
| | - Vincent T Chow
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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6
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Chua H, Feng S, Lewnard JA, Sullivan SG, Blyth CC, Lipsitch M, Cowling BJ. The Use of Test-negative Controls to Monitor Vaccine Effectiveness: A Systematic Review of Methodology. Epidemiology 2020; 31:43-64. [PMID: 31609860 PMCID: PMC6888869 DOI: 10.1097/ede.0000000000001116] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The test-negative design is an increasingly popular approach for estimating vaccine effectiveness (VE) due to its efficiency. This review aims to examine published test-negative design studies of VE and to explore similarities and differences in methodological choices for different diseases and vaccines. METHODS We conducted a systematic search on PubMed, Web of Science, and Medline, for studies reporting the effectiveness of any vaccines using a test-negative design. We screened titles and abstracts and reviewed full texts to identify relevant articles. We created a standardized form for each included article to extract information on the pathogen of interest, vaccine(s) being evaluated, study setting, clinical case definition, choices of cases and controls, and statistical approaches used to estimate VE. RESULTS We identified a total of 348 articles, including studies on VE against influenza virus (n = 253), rotavirus (n = 48), pneumococcus (n = 24), and nine other pathogens. Clinical case definitions used to enroll patients were similar by pathogens of interest but the sets of symptoms that defined them varied substantially. Controls could be those testing negative for the pathogen of interest, those testing positive for nonvaccine type of the pathogen of interest, or a subset of those testing positive for alternative pathogens. Most studies controlled for age, calendar time, and comorbidities. CONCLUSIONS Our review highlights similarities and differences in the application of the test-negative design that deserve further examination. If vaccination reduces disease severity in breakthrough infections, particular care must be taken in interpreting vaccine effectiveness estimates from test-negative design studies.
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Affiliation(s)
- Huiying Chua
- From the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Shuo Feng
- From the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Joseph A Lewnard
- Division of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, CA
| | - Sheena G Sullivan
- WHO Collaborating Centre for Reference and Research on Influenza, Royal Melbourne Hospital, and Doherty Department, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher C Blyth
- Division of Paediatrics, School of Medicine, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Western Australia, Australia
- Department of Infectious Diseases, Perth Children's Hospital, Perth, Western Australia, Australia
| | - Marc Lipsitch
- Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA
- Center for Communicable Disease Dynamics, Harvard T. H. Chan School of Public Health, Boston, MA
| | - Benjamin J Cowling
- From the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
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7
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Tan KS, Andiappan AK, Lee B, Yan Y, Liu J, Tang SA, Lum J, He TT, Ong YK, Thong M, Lim HF, Choi HW, Rotzschke O, Chow VT, Wang DY. RNA Sequencing of H3N2 Influenza Virus-Infected Human Nasal Epithelial Cells from Multiple Subjects Reveals Molecular Pathways Associated with Tissue Injury and Complications. Cells 2019; 8:cells8090986. [PMID: 31461941 PMCID: PMC6770044 DOI: 10.3390/cells8090986] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/15/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
The human nasal epithelium is the primary site of exposure to influenza virus, the initiator of host responses to influenza and the resultant pathologies. Influenza virus may cause serious respiratory infection resulting in major complications, as well as severe impairment of the airways. Here, we elucidated the global transcriptomic changes during H3N2 infection of human nasal epithelial cells from multiple individuals. Using RNA sequencing, we characterized the differentially-expressed genes and pathways associated with changes occurring at the nasal epithelium following infection. We used in vitro differentiated human nasal epithelial cell culture model derived from seven different donors who had no concurrent history of viral infections. Statistical analysis highlighted strong transcriptomic signatures significantly associated with 24 and 48 h after infection, but not at the earlier 8-h time point. In particular, we found that the influenza infection induced in the nasal epithelium early and altered responses in interferon gamma signaling, B-cell signaling, apoptosis, necrosis, smooth muscle proliferation, and metabolic alterations. These molecular events initiated at the infected nasal epithelium may potentially adversely impact the airway, and thus the genes we identified could serve as potential diagnostic biomarkers or therapeutic targets for influenza infection and associated disease management.
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Affiliation(s)
- Kai Sen Tan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | | | - Bernett Lee
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Yan Yan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Center for Interventional Medicine, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai 519000, China
| | - Jing Liu
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - See Aik Tang
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Josephine Lum
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Ting Ting He
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Yew Kwang Ong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Mark Thong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Hui Fang Lim
- Division of Respiratory and Critical Care Medicine, National University Hospital, Singapore 119074, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Hyung Won Choi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore
| | - Olaf Rotzschke
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Vincent T Chow
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore.
| | - De Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore.
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8
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Lau YF, Koh WHV, Kan C, Dua PCA, Lim ASE, Liaw CWJ, Gao QH, Chng J, Lee VJ, Tan BH, Loh JP. Epidemiologic analysis of respiratory viral infections among Singapore military servicemen in 2016. BMC Infect Dis 2018. [PMID: 29529993 PMCID: PMC5848554 DOI: 10.1186/s12879-018-3040-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Respiratory illnesses have been identified as a significant factor leading to lost training time and morbidity among Singapore military recruits. A surveillance programme has been put in place to determine etiological agents responsible for febrile, as well as afebrile respiratory illnesses in a military camp. The goal of the study is to better understand the epidemiology of these diseases and identify potential countermeasures to protect military recruits against them. Methods From Jan 2016 - Jan 2017, a total of 2647 respiratory cases were enrolled into the surveillance programme. The cases were further stratified into Febrile Respiratory Illness (FRI, with body temperature > 37.5 °C) or Acute Respiratory Illness (ARI, with body temperature < 37.5 °C). Nasal washes were collected and tested by multiplex PCR to detect 26 different pathogens. Results One thousand ninety five cases (41% of total cases) met the criteria of FRI in which 932 cases (85% of FRI cases) were screened positive for at least one virus. The most common etiological agents for FRI mono-infection cases were Adenovirus E and Rhinovirus. Recruits infected with H3N2 influenza, Influenza B and Adenovirus E viruses were most likely presented as FRI cases. Notably, H3N2 influenza resulted in the greatest rise in body temperature. The remaining 1552 cases (59% of total cases) met the criteria of ARI in which 1198 cases (77% of ARI cases) were screened positive for at least one virus. The most common etiological agent for ARI mono-infection was Rhinovirus. The distribution pattern for dual infections was different for ARI and FRI cases. Maximum number of pathogens detected in a sample was five for both groups. Conclusion Previous studies on respiratory diseases in military focused largely on FRI cases. With the expanded surveillance to ARI cases, this study allows unbiased evaluation of the impact of respiratory disease pathogens among recruits in a military environment. The results show that several pathogens have a much bigger role in causing respiratory diseases in this cohort. Electronic supplementary material The online version of this article (10.1186/s12879-018-3040-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yuk-Fai Lau
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore.
| | - Wee-Hong Victor Koh
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Clement Kan
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Poh-Choo Alethea Dua
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Ai-Sim Elizabeth Lim
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Chin-Wen Jasper Liaw
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Qiu-Han Gao
- Biodefence Centre, Ministry of Defence, Singapore, Singapore
| | - Jeremiah Chng
- Biodefence Centre, Ministry of Defence, Singapore, Singapore
| | - Vernon J Lee
- Biodefence Centre, Ministry of Defence, Singapore, Singapore
| | - Boon-Huan Tan
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Jin-Phang Loh
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
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9
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Zhao X, Ning Y, Chen MIC, Cook AR. Individual and Population Trajectories of Influenza Antibody Titers Over Multiple Seasons in a Tropical Country. Am J Epidemiol 2018; 187:135-143. [PMID: 29309522 PMCID: PMC5860523 DOI: 10.1093/aje/kwx201] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 03/06/2017] [Indexed: 01/15/2023] Open
Abstract
Seasonal influenza epidemics occur year-round in the tropics, complicating the planning of vaccination programs. We built an individual-level longitudinal model of baseline antibody levels, time of infection, and the subsequent rise and decay of antibodies postinfection using influenza A(H1N1)pdm09 data from 2 sources in Singapore: 1) a noncommunity cohort with real-time polymerase chain reaction–confirmed infections and at least 1 serological sample collected from each participant between May and October 2009 (n = 118) and 2) a community cohort with up to 6 serological samples collected between May 2009 and October 2010 (n = 760). The model was hierarchical, to account for interval censoring and interindividual variation. Model parameters were estimated via a reversible jump Markov chain Monte Carlo algorithm using custom-designed R (https://www.r-project.org/) and C++ (https://isocpp.org/) code. After infection, antibody levels peaked at 4–7 weeks, with a half-life of 26.5 weeks, followed by a slower decrease up to 1 year to approximately preinfection levels. After the third wave, the seropositivity rate and the population-level antibody titer dropped to the same level as they were at the end of the first pandemic wave. The results of this analysis are consistent with the hypothesis that the population-level effect of individuals’ waxing and waning antibodies influences influenza seasonality in the tropics.
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Affiliation(s)
- Xiahong Zhao
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Yilin Ning
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Mark I-Cheng Chen
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Department of Clinical Epidemiology, Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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10
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Kim JI, Lee I, Park S, Bae JY, Yoo K, Cheong HJ, Noh JY, Hong KW, Lemey P, Vrancken B, Kim J, Nam M, Yun SH, Cho WI, Song JY, Kim WJ, Park MS, Song JW, Kee SH, Song KJ, Park MS. Phylogenetic relationships of the HA and NA genes between vaccine and seasonal influenza A(H3N2) strains in Korea. PLoS One 2017; 12:e0172059. [PMID: 28257427 PMCID: PMC5336230 DOI: 10.1371/journal.pone.0172059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/30/2017] [Indexed: 11/18/2022] Open
Abstract
Seasonal influenza is caused by two influenza A subtype (H1N1 and H3N2) and two influenza B lineage (Victoria and Yamagata) viruses. Of these antigenically distinct viruses, the H3N2 virus was consistently detected in substantial proportions in Korea during the 2010/11-2013/14 seasons when compared to the other viruses and appeared responsible for the influenza-like illness rate peak during the first half of the 2011/12 season. To further scrutinize possible causes for this, we investigated the evolutionary and serological relationships between the vaccine and Korean H3N2 strains during the 2011/12 season for the main antigenic determinants of influenza viruses, the hemagglutinin (HA) and neuraminidase (NA) genes. In the 2011/12 season, when the number of H3N2 cases peaked, the majority of the Korean strains did not belong to the HA clade of A/Perth/16/2009 vaccine, and no Korean strains were of this lineage in the NA segment. In a serological assay, post-vaccinated human sera exhibited much reduced hemagglutination inhibition antibody titers against the non-vaccine clade Korean H3N2 strains. Moreover, Korean strains harbored several amino acid differences in the HA antigenic sites and in the NA with respect to vaccine lineages during this season. Of these, the HA antigenic site C residues 45 and 261 and the NA residue 81 appeared to be the signatures of positive selection. In subsequent seasons, when H3N2 cases were lower, the HA and NA genes of vaccine and Korean strains were more phylogenetically related to each other. Combined, our results provide indirect support for using phylogenetic clustering patterns of the HA and possibly also the NA genes in the selection of vaccine viruses and the assessment of vaccine effectiveness.
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Affiliation(s)
- Jin Il Kim
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Ilseob Lee
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Sehee Park
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Joon-Yong Bae
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Kirim Yoo
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Hee Jin Cheong
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Ji Yun Noh
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Kyung Wook Hong
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Philippe Lemey
- Department of Microbiology and Immunology, Rega Institute, KU Leuven–University of Leuven, Leuven, Belgium
| | - Bram Vrancken
- Department of Microbiology and Immunology, Rega Institute, KU Leuven–University of Leuven, Leuven, Belgium
| | - Juwon Kim
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Misun Nam
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Soo-Hyeon Yun
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Woo In Cho
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Joon Young Song
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Woo Joo Kim
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Mee Sook Park
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Jin-Won Song
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Sun-Ho Kee
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Ki-Joon Song
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, the Institute of Viral Diseases, College of Medicine, Korea University, Seoul, Republic of Korea
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11
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Hirve S, Lambach P, Paget J, Vandemaele K, Fitzner J, Zhang W. Seasonal influenza vaccine policy, use and effectiveness in the tropics and subtropics - a systematic literature review. Influenza Other Respir Viruses 2016; 10:254-67. [PMID: 26842617 PMCID: PMC4910173 DOI: 10.1111/irv.12374] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2016] [Indexed: 12/20/2022] Open
Abstract
AIM The evidence needed for tropical countries to take informed decisions on influenza vaccination is scarce. This article reviews policy, availability, use and effectiveness of seasonal influenza vaccine in tropical and subtropical countries. METHOD Global health databases were searched in three thematic areas - policy, availability and protective benefits in the context of human seasonal influenza vaccine in the tropics and subtropics. We excluded studies on monovalent pandemic influenza vaccine, vaccine safety, immunogenicity and uptake, and disease burden. RESULTS Seventy-four countries in the tropics and subtropics representing 60% of the world's population did not have a national vaccination policy against seasonal influenza. Thirty-eight countries used the Northern Hemisphere and 21 countries the Southern Hemisphere formulation. Forty-six countries targeted children and 57 targeted the elderly; though, the age cut-offs varied. Influenza vaccine supply increased twofold in recent years. However, coverage remained lower than five per 1000 population. Vaccine protection against laboratory-confirmed influenza in the tropics ranged from 0% to 42% in the elderly, 20-77% in children and 50-59% in healthy adults. Vaccinating pregnant women against seasonal influenza prevented laboratory-confirmed influenza in both mothers (50%) and their infants <6 months (49-63%). CONCLUSION Guidelines on vaccine composition, priority risk groups and vaccine availability varied widely. The evidence on vaccine protection was scarce. Countries in the tropics and subtropics need to strengthen and expand their evidence-base required for making informed decisions on influenza vaccine introduction and expansion, and how much benefit to expect.
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Affiliation(s)
| | - Philipp Lambach
- Initiative for Vaccine ResearchWorld Health OrganizationGenevaSwitzerland
| | | | | | - Julia Fitzner
- Global Influenza ProgramWorld Health OrganizationGenevaSwitzerland
| | - Wenqing Zhang
- Global Influenza ProgramWorld Health OrganizationGenevaSwitzerland
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12
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Pang J, Jin J, Loh JP, Tan BH, Koh WHV, Ng SH, Ho ZJM, Gao Q, Cook AR, Hsu LY, Lee VJ, Chen MIC. Risk factors for febrile respiratory illness and mono-viral infections in a semi-closed military environment: a case-control study. BMC Infect Dis 2015. [PMID: 26208494 PMCID: PMC4514976 DOI: 10.1186/s12879-015-1024-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Febrile respiratory illness (FRI) results in substantial burden in semi-closed environments. Tackling risk factors may reduce transmission and infection. However, risk factors involved in one setting may not be generalizable in all settings due to differences in climate, residential environment, population genetic and cultural backgrounds. This study aims to identify risk factors of FRI and mono-viral infections in a tropical military environment. Methods From year 2009 to 2012, military personnel with temperature ≥37.5 °C, cough and/or sore throat, and personnel with no fever or no respiratory symptoms were recruited as cases and controls, respectively. Subjects provided nasal wash specimens and answered a standardized questionnaire. Resplex assays were used to determine the viral etiologies. Descriptive, univariate and multivariate analyses of the variables were performed using appropriate descriptive tests and logistic regression modelling, respectively, with R program. Results A total of 7,743 FRI cases and 1,247 non-FRI study controls were recruited. Increasing age [adjusted odds ratio (AOR) = 1.03; 95 % confidence interval (CI) = 1.01-1.05], recruit camp (AOR = 4.67; 95 % CI = 3.99-5.46) and smoker (AOR = 1.31; 95 % CI = 1.13-1.52) were independent risk factors of FRI. Malay ethnicity was positively associated with influenza A(H1N1)pdm09 (AOR = 1.50; 95 % CI = 1.04-2.15) and coxsackie/echovirus (AOR = 1.67; 95 % CI = 1.19-2.36) mono-infection. Significant contact risk factors were stay-out personnel with ill household member (AOR = 4.96; 95 % CI = 3.39-7.24), and stay-in personnel with ill bunkmate and household member (AOR = 3.55; 95 % CI = 2.57-4.91). Staying in camp with none ill in bunk and at home was a protective factor against FRI (AOR = 0.80; 95 % CI = 0.64-0.99). These contact risk factors were similarly observed for the five most common viruses detected, namely adenovirus, rhinoviruses, influenza A and B, and coxsackie/echovirus. Conclusion Increasing age, smoker, recruit-camp, stay-out personnel with ill household members and stay-in personnel with ill bunkmates were independent risk factors of FRI in a semi-closed military environment. Early identification and isolation of ill personnel from their bunk may be effective to prevent and reduce transmission and disease burden.
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Affiliation(s)
- Junxiong Pang
- Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore. .,Communicable Disease Centre, Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore.
| | - Jing Jin
- Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
| | - Jin Phang Loh
- Defence Medical and Environmental Research Institute, Singapore, Singapore.
| | - Boon Huan Tan
- Defence Medical and Environmental Research Institute, Singapore, Singapore.
| | | | - Sock Hoon Ng
- Defence Medical and Environmental Research Institute, Singapore, Singapore.
| | | | - Qiuhan Gao
- Biodefence Centre, Ministry of Defence, Singapore, Singapore.
| | - Alex R Cook
- Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore. .,Yale-NUS College, National University of Singapore, Singapore, Singapore. .,Program in Health Services and Systems Research, Duke-NUS Graduate Medical School, Singapore, Singapore. .,Department of Statistics and Applied Probability, National University of Singapore, Singapore, Singapore.
| | - Li Yang Hsu
- Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore. .,Department of Medicine, National University of Singapore, Singapore, Singapore.
| | - Vernon J Lee
- Biodefence Centre, Ministry of Defence, Singapore, Singapore.
| | - Mark I Cheng Chen
- Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore. .,Communicable Disease Centre, Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore.
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13
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Sullivan SG, Feng S, Cowling BJ. Potential of the test-negative design for measuring influenza vaccine effectiveness: a systematic review. Expert Rev Vaccines 2014; 13:1571-91. [PMID: 25348015 PMCID: PMC4277796 DOI: 10.1586/14760584.2014.966695] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The test-negative design is a variant of the case-control study being increasingly used to study influenza vaccine effectiveness (VE). In these studies, patients with influenza-like illness are tested for influenza. Vaccine coverage is compared between those testing positive versus those testing negative to estimate VE. OBJECTIVES We reviewed features in the design, analysis and reporting of 85 published test-negative studies. DATA SOURCES Studies were identified from PubMed, reference lists and email updates. Study eligibility: All studies using the test-negative design reporting end-of-season estimates were included. STUDY APPRAISAL Design features that may affect the validity and comparability of reported estimates were reviewed, including setting, study period, source population, case definition, exposure and outcome ascertainment and statistical model. RESULTS There was considerable variation in the analytic approach, with 68 unique statistical models identified among the studies. CONCLUSION Harmonization of analytic approaches may improve the potential for pooling VE estimates.
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Affiliation(s)
- Sheena G Sullivan
- WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, 792 Elizabeth St, Melbourne VIC 3000, Australia
| | - Shuo Feng
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Benjamin J Cowling
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
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