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ElSherif M, Andrew MK, Ye L, Ambrose A, Boivin G, Bowie W, David MP, Gruselle O, Halperin SA, Hatchette TF, Johnstone J, Katz K, Langley JM, Loeb M, MacKinnon-Cameron D, McCarthy A, McElhaney JE, McGeer A, Poirier A, Pirçon JY, Powis J, Richardson D, Semret M, Smith S, Smyth D, Trottier S, Valiquette L, Webster D, McNeil SA, LeBlanc JJ. Leveraging Influenza Virus Surveillance From 2012 to 2015 to Characterize the Burden of Respiratory Syncytial Virus Disease in Canadian Adults ≥50 Years of Age Hospitalized With Acute Respiratory Illness. Open Forum Infect Dis 2023; 10:ofad315. [PMID: 37441353 PMCID: PMC10334379 DOI: 10.1093/ofid/ofad315] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/12/2023] [Indexed: 07/15/2023] Open
Abstract
Background Respiratory syncytial virus (RSV) disease in older adults is undercharacterized. To help inform future immunization policies, this study aimed to describe the disease burden in Canadian adults aged ≥50 years hospitalized with RSV. Methods Using administrative data and nasopharyngeal swabs collected from active surveillance among adults aged ≥50 years hospitalized with an acute respiratory illness (ARI) during the 2012-2013, 2013-2014, and 2014-2015 influenza seasons, RSV was identified using a respiratory virus multiplex polymerase chain reaction test to describe the associated disease burden, incidence, and healthcare costs. Results Of 7797 patients tested, 371 (4.8%) were RSV positive (2.2% RSV-A and 2.6% RSV-B). RSV prevalence varied by season from 4.2% to 6.2%. Respiratory virus coinfection was observed in 11.6% (43/371) of RSV cases, with influenza A being the most common. RSV hospitalization rates varied between seasons and increased with age, from 8-12 per 100 000 population in adults aged 50-59 years to 174-487 per 100 000 in adults aged ≥80 years. The median age of RSV cases was 74.9 years, 63.7% were female, and 98.1% of cases had ≥1 comorbidity. Among RSV cases, the mean length of hospital stay was 10.6 days, 13.7% were admitted to the intensive care unit, 6.4% required mechanical ventilation, and 6.1% died. The mean cost per RSV case was $13 602 (Canadian dollars) but varied by age and Canadian province. Conclusions This study adds to the growing literature on adult RSV burden by showing considerable morbidity, mortality, and healthcare costs in hospitalized adults aged ≥50 years with ARIs such as influenza.
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Affiliation(s)
- May ElSherif
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Melissa K Andrew
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Lingyun Ye
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ardith Ambrose
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Guy Boivin
- Centre de Recherche du Centre hospitalier universitaire de Québec-Université Laval, Québec City, Québec, Canada
| | - William Bowie
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Scott A Halperin
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Todd F Hatchette
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Kevin Katz
- North York General Hospital, Toronto, Ontario, Canada
| | - Joanne M Langley
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Loeb
- McMaster University, Hamilton, Ontario, Canada
| | - Donna MacKinnon-Cameron
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | | | - Andre Poirier
- Centre intégré universitaire de santé et services sociaux de la Mauricie et du Centre du Québec, Québec City, Québec, Canada
| | | | - Jeff Powis
- Michael Garron Hospital, Toronto, Ontario, Canada
| | | | | | | | - Daniel Smyth
- The Moncton Hospital, Moncton, New Brunswick, Canada
| | - Sylvie Trottier
- Centre de Recherche du Centre hospitalier universitaire de Québec-Université Laval, Québec City, Québec, Canada
| | | | - Duncan Webster
- Saint John Regional Hospital, Saint John, New Brunswick, Canada
| | - Shelly A McNeil
- Correspondence: Jason J. LeBlanc, PhD, FCCM, D(ABMM), Division of Microbiology, Nova Scotia Health, Queen Elizabeth II Health Sciences Centre, Room 404B, Mackenzie Bldg, 5788 University Ave, Halifax, NS B3H 1V8, Canada (); Shelly McNeil, MD, FRCPC, FIDSA, Canadian Center for Vaccinology, IWK Health Centre, 4th Floor Goldbloom Pavilion, 5850/5980 University Ave, Halifax, NS B3K 6R8, Canada ()
| | - Jason J LeBlanc
- Correspondence: Jason J. LeBlanc, PhD, FCCM, D(ABMM), Division of Microbiology, Nova Scotia Health, Queen Elizabeth II Health Sciences Centre, Room 404B, Mackenzie Bldg, 5788 University Ave, Halifax, NS B3H 1V8, Canada (); Shelly McNeil, MD, FRCPC, FIDSA, Canadian Center for Vaccinology, IWK Health Centre, 4th Floor Goldbloom Pavilion, 5850/5980 University Ave, Halifax, NS B3K 6R8, Canada ()
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Deng X, Chen Z, Zhao Z, Chen J, Li M, Yang J, Yu H. Regional characteristics of influenza seasonality patterns in mainland China, 2005-2017: a statistical modeling study. Int J Infect Dis 2023; 128:91-97. [PMID: 36581188 DOI: 10.1016/j.ijid.2022.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 12/06/2022] [Accepted: 12/21/2022] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES To quantify the seasonal and antigenic characteristics of influenza to help understand influenza activity and inform vaccine recommendations. METHODS We employed a generalized linear model with harmonic terms to quantify the seasonal pattern of influenza in China from 2005-2017, including amplitude (circulatory intensity), semiannual periodicity (given two peaks a year), annual peak time, and epidemic duration. The antigenic differences were distinguished as antigenic similarity between 2009 and 2020. We categorized regions above 33° N, between 27° N and 33° N, and below 27° N as the north, central, and south regions, respectively. RESULTS We estimated that the amplitude in the north region (median: 0.019, 95% CI: 0.018-0.021) was significantly higher than that in the central region (median: 0.011, 95% CI: 0.01-0.012, P <0.001) and south region (median: 0.008, 95% CI: 0.007-0.008, P <0.001) for influenza A virus subtype H3N2 (A/H3N2). The A/H3N2 in the central region had a semiannual periodicity (median: 0.548, 95% CI: 0.517-0.577), while no semiannual pattern was found in other regions or subtypes/lineages. The antigenic similarity was low (below 50% in the 2009-2010, 2014-2015, 2016-2018, and 2019-2020 seasons) for A/H3N2. CONCLUSION Our study depicted the seasonal pattern differences and antigenic differences of influenza in China, which provides information for vaccination strategies.
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Affiliation(s)
- Xiaowei Deng
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Zhiyuan Chen
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Zeyao Zhao
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Junbo Chen
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Mei Li
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Juan Yang
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China
| | - Hongjie Yu
- Department of Infectious Diseases, Huashan Hospital, School of Public Health, Fudan University, Shanghai, China; Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China; National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China.
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Majeed B, David JF, Bragazzi NL, McCarthy Z, Grunnill MD, Heffernan J, Wu J, Woldegerima WA. Mitigating co-circulation of seasonal influenza and COVID-19 pandemic in the presence of vaccination: A mathematical modeling approach. Front Public Health 2023; 10:1086849. [PMID: 36684896 PMCID: PMC9845909 DOI: 10.3389/fpubh.2022.1086849] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 11/28/2022] [Indexed: 01/05/2023] Open
Abstract
The co-circulation of two respiratory infections with similar symptoms in a population can significantly overburden a healthcare system by slowing the testing and treatment. The persistent emergence of contagious variants of SARS-CoV-2, along with imperfect vaccines and their waning protections, have increased the likelihood of new COVID-19 outbreaks taking place during a typical flu season. Here, we developed a mathematical model for the co-circulation dynamics of COVID-19 and influenza, under different scenarios of influenza vaccine coverage, COVID-19 vaccine booster coverage and efficacy, and testing capacity. We investigated the required minimal and optimal coverage of COVID-19 booster (third) and fourth doses, in conjunction with the influenza vaccine, to avoid the coincidence of infection peaks for both diseases in a single season. We show that the testing delay brought on by the high number of influenza cases impacts the dynamics of influenza and COVID-19 transmission. The earlier the peak of the flu season and the greater the number of infections with flu-like symptoms, the greater the risk of flu transmission, which slows down COVID-19 testing, resulting in the delay of complete isolation of patients with COVID-19 who have not been isolated before the clinical presentation of symptoms and have been continuing their normal daily activities. Furthermore, our simulations stress the importance of vaccine uptake for preventing infection, severe illness, and hospitalization at the individual level and for disease outbreak control at the population level to avoid putting strain on already weak and overwhelmed healthcare systems. As such, ensuring optimal vaccine coverage for COVID-19 and influenza to reduce the burden of these infections is paramount. We showed that by keeping the influenza vaccine coverage about 35% and increasing the coverage of booster or fourth dose of COVID-19 not only reduces the infections with COVID-19 but also can delay its peak time. If the influenza vaccine coverage is increased to 55%, unexpectedly, it increases the peak size of influenza infections slightly, while it reduces the peak size of COVID-19 as well as significantly delays the peaks of both of these diseases. Mask-wearing coupled with a moderate increase in the vaccine uptake may mitigate COVID-19 and prevent an influenza outbreak.
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Affiliation(s)
- Bushra Majeed
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Jummy Funke David
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Nicola Luigi Bragazzi
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Zack McCarthy
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Martin David Grunnill
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Jane Heffernan
- Centre for Disease Modeling, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
- Modelling Infection and Immunity Lab, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Jianhong Wu
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Woldegebriel Assefa Woldegerima
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada
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Picard E, Armstrong S, Andrew MK, Haynes L, Loeb M, Pawelec G, Kuchel GA, McElhaney JE, Verschoor CP. Markers of systemic inflammation are positively associated with influenza vaccine antibody responses with a possible role for ILT2(+)CD57(+) NK-cells. Immun Ageing 2022; 19:26. [PMID: 35619117 PMCID: PMC9134679 DOI: 10.1186/s12979-022-00284-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/15/2022] [Indexed: 02/06/2023]
Abstract
Background With increasing age, overall health declines while systemic levels of inflammatory mediators tend to increase. Although the underlying mechanisms are poorly understood, there is a wealth of data suggesting that this so-called “inflammaging” contributes to the risk of adverse outcomes in older adults. We sought to determine whether markers of systemic inflammation were associated with antibody responses to the seasonal influenza vaccine. Results Over four seasons, hemagglutination inhibition antibody titres and ex vivo bulk peripheral blood mononuclear cell (PBMC) responses to live influenza viruses assessed via interferon (IFN)-γ/interleukin (IL)-10 production, were measured pre- and 4-weeks post-vaccination in young adults (n = 79) and older adults randomized to standard- or high-dose inactivated vaccine (n = 612). Circulating tumour necrosis factor (TNF), interleukin (IL)-6 and C-reactive protein (CRP) were also measured pre-vaccination. Post-vaccination antibody titres were significantly associated with systemic inflammatory levels; specifically, IL-6 was positively associated with A/H3N2 titres in young adults (Cohen’s d = 0.36), and in older high-dose, but not standard-dose recipients, all systemic inflammatory mediators were positively associated with A/H1N1, A/H3N2 and B titres (d = 0.10–0.45). We further show that the frequency of ILT2(+)CD57(+) CD56-Dim natural killer (NK)-cells was positively associated with both plasma IL-6 and post-vaccination A/H3N2 titres in a follow-up cohort of older high-dose recipients (n = 63). Pathway analysis suggested that ILT2(+)CD57(+) Dim NK-cells mediated 40% of the association between IL-6 and A/H3N2 titres, which may be related to underlying participant frailty. Conclusions In summary, our data suggest a complex relationship amongst influenza vaccine responses, systemic inflammation and NK-cell phenotype in older adults, which depends heavily on age, vaccine dose and possibly overall health status. While our results suggest that “inflammaging” may increase vaccine immunogenicity in older adults, it is yet to be determined whether this enhancement contributes to improved protection against influenza disease. Supplementary Information The online version contains supplementary material available at 10.1186/s12979-022-00284-x.
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Domnich A, Panatto D, Pariani E, Napoli C, Chironna M, Manini I, Rizzo C, Orsi A, Icardi G. Relative effectiveness of the adjuvanted vs non-adjuvanted seasonal influenza vaccines against severe laboratory-confirmed influenza among hospitalized Italian older adults. Int J Infect Dis 2022; 125:164-169. [PMID: 36332902 DOI: 10.1016/j.ijid.2022.10.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/17/2022] [Accepted: 10/27/2022] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES In this study, we aimed to investigate the relative vaccine effectiveness (rVE) of the MF59-adjuvanted trivalent (aTIV) and non-adjuvanted quadrivalent (QIVe) egg-based standard-dose vaccines against severe laboratory-confirmed influenza. METHODS This test-negative case-control study was conducted in a hospital setting during four recent Italian influenza seasons (from 2018/19 to 2021/22). The clinical outcome was severe acute respiratory infection (SARI) with laboratory confirmation diagnosed among subjects aged ≥65 years. rVE of aTIV versus QIVe was estimated through propensity score matching followed by logistic regression. RESULTS The influenza virus circulated to a significant extent only during the 2018/19 and 2019/20 seasons. The final population included 512 vaccinated older adults, of which 83 were cases and 429 were test-negative controls. aTIV and QIVe users differed substantially from the point of view of several baseline characteristics. The propensity score adjusted rVE of aTIV vs QIVe was 59.2% (95% CI: 14.6%, 80.5%), 54.7% (95% CI: -28.7%, 84.0%) and 56.9% (95% CI: -7.8%, 82.8%) against any influenza, A(H1N1)pdm09 and A(H3N2), respectively. CONCLUSION aTIV was more effective than QIVe in preventing laboratory-confirmed SARI. The benefits of aTIV may be obscured by confounding indication.
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Affiliation(s)
- Alexander Domnich
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy.
| | - Donatella Panatto
- Department of Health Sciences, University of Genoa, Genoa, Italy; Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
| | - Elena Pariani
- Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy; Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | | | - Maria Chironna
- Interdisciplinary Department of Medicine, University of Bari, Bari, Italy
| | - Ilaria Manini
- Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Caterina Rizzo
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Andrea Orsi
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy; Department of Health Sciences, University of Genoa, Genoa, Italy; Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
| | - Giancarlo Icardi
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy; Department of Health Sciences, University of Genoa, Genoa, Italy; Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
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Chen Z, Bancej C, Lee L, Champredon D. Antigenic drift and epidemiological severity of seasonal influenza in Canada. Sci Rep 2022; 12:15625. [PMID: 36115880 PMCID: PMC9482630 DOI: 10.1038/s41598-022-19996-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/07/2022] [Indexed: 12/05/2022] Open
Abstract
Seasonal influenza epidemics circulate globally every year with varying levels of severity. One of the major drivers of this seasonal variation is thought to be the antigenic drift of influenza viruses, resulting from the accumulation of mutations in viral surface proteins. In this study, we aimed to investigate the association between the genetic drift of seasonal influenza viruses (A/H1N1, A/H3N2 and B) and the epidemiological severity of seasonal epidemics within a Canadian context. We obtained hemagglutinin protein sequences collected in Canada between the 2006/2007 and 2019/2020 flu seasons from GISAID and calculated Hamming distances in a sequence-based approach to estimating inter-seasonal antigenic differences. We also gathered epidemiological data on cases, hospitalizations and deaths from national surveillance systems and other official sources, as well as vaccine effectiveness estimates to address potential effect modification. These aggregate measures of disease severity were integrated into a single seasonal severity index. We performed linear regressions of our severity index with respect to the inter-seasonal antigenic distances, controlling for vaccine effectiveness. We did not find any evidence of a statistical relationship between antigenic distance and seasonal influenza severity in Canada. Future studies may need to account for additional factors, such as co-circulation of other respiratory pathogens, population imprinting, cohort effects and environmental parameters, which may drive seasonal influenza severity.
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Affiliation(s)
- Zishu Chen
- National Microbiology Laboratory, Public Health Risk Sciences Division, Public Health Agency of Canada, Guelph, ON, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Christina Bancej
- Surveillance and Epidemiology Division, Centre for Immunization and Respiratory Infectious Disease, Public Health Agency of Canada, Ottawa, ON, Canada
| | - Liza Lee
- Surveillance and Epidemiology Division, Centre for Immunization and Respiratory Infectious Disease, Public Health Agency of Canada, Ottawa, ON, Canada
| | - David Champredon
- National Microbiology Laboratory, Public Health Risk Sciences Division, Public Health Agency of Canada, Guelph, ON, Canada.
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Influenza Viruses and Vaccines: The Role of Vaccine Effectiveness Studies for Evaluation of the Benefits of Influenza Vaccines. Vaccines (Basel) 2022; 10:vaccines10050714. [PMID: 35632470 PMCID: PMC9143275 DOI: 10.3390/vaccines10050714] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Influenza is a vaccine preventable disease and vaccination remains the most effective method of controlling the morbidity and mortality of seasonal influenza, especially with respect to risk groups. To date, three types of influenza vaccines have been licensed: inactivated, live-attenuated, and recombinant haemagglutinin vaccines. Effectiveness studies allow an assessment of the positive effects of influenza vaccines in the field. The effectiveness of current influenza is suboptimal, being estimated as 40% to 60% when the vaccines strains are antigenically well-matched with the circulating viruses. This review focuses on influenza viruses and vaccines and the role of vaccine effectiveness studies for evaluating the benefits of influenza vaccines. Overall, influenza vaccines are effective against morbidity and mortality in all age and risk groups, especially in young children and older adults. However, the effectiveness is dependent on several factors such as the age of vaccinees, the match between the strain included in the vaccine composition and the circulating virus, egg-adaptations occurring during the production process, and the subject’s history of previous vaccination.
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Andrew MK, MacDonald S, Godin J, McElhaney JE, LeBlanc J, Hatchette TF, Bowie W, Katz K, McGeer A, Semret M, McNeil SA. Persistent Functional Decline Following Hospitalization with Influenza or Acute Respiratory Illness. J Am Geriatr Soc 2021; 69:696-703. [PMID: 33294986 PMCID: PMC7984066 DOI: 10.1111/jgs.16950] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/15/2020] [Accepted: 10/23/2020] [Indexed: 01/23/2023]
Abstract
BACKGROUND/OBJECTIVES Influenza is associated with significant morbidity and mortality, particularly for older adults. Persistent functional decline following hospitalization has important impacts on older adults' wellbeing and independence, but has been under-studied in relation to influenza. We aimed to investigate persistent functional change in older adults admitted to hospital with influenza and other acute respiratory illness (ARI). DESIGN Protective observational cohort study. SETTING Canadian Immunization Research Network Serious Outcomes Surveillance Network 2011 to 2012 influenza season. PARTICIPANTS A total of 925 patients aged 65 and older admitted to hospital with influenza and other ARI. MEASUREMENTS Influenza was laboratory-confirmed. Frailty was measured using a Frailty index (FI). Functional status was measured using the Barthel index (BI); moderate persistent functional decline was defined as a clinically meaningful loss of ≥10 to <20 points on the 100-point BI. Catastrophic disability (CD) was defined as a loss of ≥20 points, equivalent to full loss of independence in two basic activities of daily living. RESULTS Five hundred and nineteen (56.1%) were women; mean age was 79.4 (standard deviation=8.4) years. Three hundred and forty-six (37.4%) had laboratory-confirmed influenza. Influenza cases had lower baseline function (BI = 77.0 vs 86.9, P < .001) and higher frailty (FI = 0.23 vs 0.20, P < .001) than those with other ARI. A total of 8.4% died, 8.2% experienced persistent moderate functional decline, and 9.9% experienced CD. Higher baseline frailty was associated with increased odds of experiencing functional decline, CD, and death. The experience of functional decline and CD, and its association with frailty, was the same for influenza and other ARI. CONCLUSION Functional loss in hospital is common among older adults; for some this functional loss is persistent and catastrophic. This highlights the importance of prevention and optimal management of acute declines in health, including influenza, to avoid hospitalization. In the case of influenza, for which vaccines exist, this raises the potential of vaccine preventable disability.
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Affiliation(s)
- Melissa K. Andrew
- Geriatric Medicine Research, Department of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
- Canadian Center for VaccinologyHalifaxNova ScotiaCanada
| | - Sarah MacDonald
- Department of Family MedicineDalhousie UniversityHalifaxNova ScotiaCanada
| | - Judith Godin
- Geriatric Medicine Research, Department of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
| | | | - Jason LeBlanc
- Canadian Center for VaccinologyHalifaxNova ScotiaCanada
- Department of PathologyDalhousie UniversityHalifaxNova ScotiaCanada
| | - Todd F. Hatchette
- Canadian Center for VaccinologyHalifaxNova ScotiaCanada
- Department of Medicine (Infectious Diseases)Dalhousie UniversityHalifaxNova ScotiaCanada
| | - William Bowie
- Department of Medicine (Infectious Diseases)University of British ColumbiaVancouverBritish ColumbiaCanada
| | - Kevin Katz
- North York General HospitalTorontoOntarioCanada
| | | | - Makeda Semret
- McGill University Health Centre Research InstituteMontrealQuebecCanada
| | - Shelly A. McNeil
- Canadian Center for VaccinologyHalifaxNova ScotiaCanada
- Department of Medicine (Infectious Diseases)Dalhousie UniversityHalifaxNova ScotiaCanada
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Respiratory Epithelial Cells Respond to Lactobacillus plantarum but Provide No Cross-Protection against Virus-Induced Inflammation. Viruses 2020; 13:v13010002. [PMID: 33374950 PMCID: PMC7821944 DOI: 10.3390/v13010002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/15/2022] Open
Abstract
Virus-induced inflammation plays a critical role in determining the clinical outcome of an acute respiratory virus infection. We have shown previously that the administration of immunobiotic Lactobacillus plantarum (Lp) directly to the respiratory tract prevents lethal inflammatory responses to subsequent infection with a mouse respiratory virus pathogen. While Lp-mediated protective responses involve non-redundant contributions of both Toll-like receptor 2 (TLR2) and NOD2, the cellular basis of these findings remains unclear. Here, we address the impact of Lp and its capacity to suppress inflammation in virus-infected respiratory epithelial cells in two cell culture models. We found that both MLE-12 cells and polarized mouse tracheal epithelial cells (mTECs) were susceptible to infection with Influenza A and released proinflammatory cytokines, including CCL2, CCL5, CXCL1, and CXCL10, in response to replicating virus. MLE-12 cells express NOD2 (81 ± 6.3%) and TLR2 (19 ± 4%), respond to Lp, and are TLR2-specific, but not NOD2-specific, biochemical agonists. By contrast, we found that mTECs express NOD2 (81 ± 17%) but minimal TLR2 (0.93 ± 0.58%); nonetheless, mTECs respond to Lp and the TLR2 agonist, Pam2CSK4, but not NOD2 agonists or the bifunctional TLR2-NOD2 agonist, CL-429. Although MLE-12 cells and mTECS were both activated by Lp, little to no cytokine suppression was observed in response to Lp followed by virus infection via a protocol that replicated experimental conditions that were effective in vivo. Further study and a more complex approach may be required to reveal critical factors that suppress virus-induced inflammatory responses.
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Nichols MK, Andrew MK, Ye L, Hatchette TF, Ambrose A, Boivin G, Bowie W, Dos Santos G, Elsherif M, Green K, Haguinet F, Katz K, Leblanc J, Loeb M, MacKinnon-Cameron D, McCarthy A, McElhaney JE, McGeer A, Powis J, Richardson D, Semret M, Sharma R, Shinde V, Smyth D, Trottier S, Valiquette L, Webster D, McNeil SA. The Impact of Prior Season Vaccination on Subsequent Influenza Vaccine Effectiveness to Prevent Influenza-related Hospitalizations Over 4 Influenza Seasons in Canada. Clin Infect Dis 2020; 69:970-979. [PMID: 30508064 DOI: 10.1093/cid/ciy1009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 11/30/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Recent studies have demonstrated the possibility of negative associations between prior influenza vaccines and subsequent influenza vaccine effectiveness (VE), depending on season and strain. We investigated this association over 4 consecutive influenza seasons (2011-2012 through 2014-2015) in Canada. METHODS Using a matched test-negative design, laboratory-confirmed influenza cases and matched test-negative controls admitted to hospitals were enrolled. Patients were stratified into 4 groups according to influenza vaccine history (not vaccinated current and prior season [referent], vaccinated prior season only, vaccinated current season only, and vaccinated both current and prior season). Conditional logistic regression was used to estimate VE; prior vaccine impact was assessed each season for overall effect and effect stratified by age (<65 years, ≥65 years) and type/subtype (A/H1N1, A/H3N2, influenza B). RESULTS Overall, mainly nonsignificant associations were observed. Trends of nonsignificant decreased VE among patients repeatedly vaccinated in both prior and current season relative to the current season only were observed in the A/H3N2-dominant seasons of 2012-2013 and 2014-2015. Conversely, in 2011-2012, during which B viruses circulated, and in 2013-2014, when A/H1N1 circulated, being vaccinated in both seasons tended to result in a high VE in the current season against the dominant circulating subtype. CONCLUSIONS Prior vaccine impact on subsequent VE among Canadian inpatients was mainly nonsignificant. Even in circumstances where we observed a trend of negative impact, being repeatedly vaccinated was still more effective than not receiving the current season's vaccine. These findings favor continuation of annual influenza vaccination recommendations, particularly in older adults. CLINICAL TRIALS REGISTRATION NCT01517191.
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Affiliation(s)
- M K Nichols
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - M K Andrew
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - L Ye
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - T F Hatchette
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - A Ambrose
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - G Boivin
- Centre Hospitalier Universitaire de Québec, Québec City, Canada
| | - W Bowie
- University of British Columbia, Vancouver, Canada
| | - G Dos Santos
- Business and Decision Life Sciences, Bruxelles, Belgium.,Present affiliation: GSK, Wavre, Belgium
| | - M Elsherif
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - K Green
- Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - K Katz
- North York General Hospital, Toronto
| | - J Leblanc
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | - M Loeb
- McMaster University, Hamilton
| | - D MacKinnon-Cameron
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
| | | | | | - A McGeer
- Mount Sinai Hospital, Toronto, Ontario, Canada
| | - J Powis
- Michael Garron Hospital, Toronto
| | | | - M Semret
- McGill University, Montreal, Québec
| | - R Sharma
- GSK, Mississauga, Ontario, Canada
| | - V Shinde
- GSK, King of Prussia, Pennsylvania.,Present affiliation: Novavax Vaccines, Washington, D.C
| | - D Smyth
- The Moncton Hospital, New Brunswick
| | - S Trottier
- Centre Hospitalier Universitaire de Québec, Québec City, Canada
| | | | - D Webster
- Saint John Hospital Regional Hospital, Dalhousie University, New Brunswick, Canada
| | - S A McNeil
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia
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11
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A case study of an influenza vaccination program for health care workers in Vietnam. BMC Health Serv Res 2020; 20:785. [PMID: 32831071 PMCID: PMC7444161 DOI: 10.1186/s12913-020-05663-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/17/2020] [Indexed: 12/04/2022] Open
Abstract
Background In 2017, the Vietnam Ministry of Health conducted a demonstration project to introduce seasonal influenza vaccination to health care workers. A total of 11,000 doses of influenza vaccine, single-dose prefilled syringes, were provided free to HCWs at 29 selected hospitals, clinics, and research institutes in four provinces: Hanoi, Khanh Hoa, Dak Lak and Ho Chi Minh City. Methods Before the campaign, a workshop was organized to discuss an implementation plan including technical requirements, cold chain, uptake reporting, and surveillance for adverse events following immunization. All sites distributed communication materials and encouraged their staff to register for vaccination. Following immunization sessions, sites sent reports on uptake and adverse events following immunization. Left-over vaccine was transferred to other sites to maximize vaccine use. Results The average uptake was 57% for all health care workers, with 11 sites achieving 90% and above. These 11 sites were small with less than 500 staff, including 5 primary hospitals, 3 preventive medicine units, and 2 referral hospitals. Among the six biggest sites with over 1000 staff, four sites had the lowest uptake (14–47%). Most of the high-uptake sites were from the central to the south; only one site, a referral hospital, was from the north. After redistribution of left-over vaccine, only 130 vaccine doses (1.2%) were not used and destroyed. Based on factors that affected uptake, including registration levels, differing communication strategies, availability of vaccination, and commitment by health facility leaders, we recommended ways to increase health care worker coverage; recommendations to improve reporting adverse events following immunization were also made. Conclusions The project demonstrated that it was feasible to conduct influenza vaccination campaigns among health care workers in Vietnam. Improvements in promotion of registration, more intense pre-planning, especially at larger facilities, and wider, more consistent availability of communication materials will result in increased efficiency and coverage in this program’s future expansion.
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12
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Lees C, Godin J, McElhaney JE, McNeil SA, Loeb M, Hatchette TF, LeBlanc J, Bowie W, Boivin G, McGeer A, Poirier A, Powis J, Semret M, Webster D, Andrew MK. Frailty Hinders Recovery From Influenza and Acute Respiratory Illness in Older Adults. J Infect Dis 2020. [PMID: 32147711 DOI: 10.1093/infdis/jiaa092[publishedonlinefirst:2020/03/10]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND We examined frailty as a predictor of recovery in older adults hospitalized with influenza and acute respiratory illness. METHODS A total of 5011 patients aged ≥65 years were admitted to Canadian Serious Outcomes Surveillance Network hospitals during the 2011/2012, 2012/2013, and 2013/2014 influenza seasons. Frailty was measured using a previously validated frailty index (FI). Poor recovery was defined as death by 30 days postdischarge or an increase of more than 0.06 (≥2 persistent new health deficits) on the FI. Multivariable logistic regression controlled for age, sex, season, influenza diagnosis, and influenza vaccination status. RESULTS Mean age was 79.4 (standard deviation = 8.4) years; 53.1% were women. At baseline, 15.0% (n = 750) were nonfrail, 39.3% (n = 1971) were prefrail, 39.8% (n = 1995) were frail, and 5.9% (n = 295) were most frail. Poor recovery was experienced by 21.4%, 52.0% of whom had died. Frailty was associated with lower odds of recovery in all 3 seasons: 2011/2012 (odds ratio [OR] = 0.70; 95% confidence interval [CI], 0.59-0.84), 2012/2013 (OR = 0.72; 95% CI, 0.66-0.79), and 2013/2014 (OR = 0.75; 95% CI, 0.69-0.82); results varied by season, influenza status, vaccination status, and age. CONCLUSIONS Increasing frailty is associated with lower odds of recovery, and persistent worsening frailty is an important adverse outcome of acute illness.
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Affiliation(s)
- Caitlin Lees
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Judith Godin
- Geriatric Medicine Research, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Shelly A McNeil
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Loeb
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Todd F Hatchette
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jason LeBlanc
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Pathology and Laboratory Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - William Bowie
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Guy Boivin
- Centre Hospitalier Universitaire de Québec, Quebec City, Quebec, Canada
| | | | - André Poirier
- Centre Intégré Universitaire de Santé et Services Sociaux, Quebec City, Quebec, Canada
| | - Jeff Powis
- Michael Garron Hospital, Toronto, Ontario, Canada
| | | | - Duncan Webster
- Saint John Hospital Regional Hospital, Dalhousie University, New Brunswick, Canada
| | - Melissa K Andrew
- Geriatric Medicine Research, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
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13
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Lees C, Godin J, McElhaney JE, McNeil SA, Loeb M, Hatchette TF, LeBlanc J, Bowie W, Boivin G, McGeer A, Poirier A, Powis J, Semret M, Webster D, Andrew MK. Frailty Hinders Recovery From Influenza and Acute Respiratory Illness in Older Adults. J Infect Dis 2020; 222:428-437. [PMID: 32147711 PMCID: PMC7336554 DOI: 10.1093/infdis/jiaa092] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 03/03/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND We examined frailty as a predictor of recovery in older adults hospitalized with influenza and acute respiratory illness. METHODS A total of 5011 patients aged ≥65 years were admitted to Canadian Serious Outcomes Surveillance Network hospitals during the 2011/2012, 2012/2013, and 2013/2014 influenza seasons. Frailty was measured using a previously validated frailty index (FI). Poor recovery was defined as death by 30 days postdischarge or an increase of more than 0.06 (≥2 persistent new health deficits) on the FI. Multivariable logistic regression controlled for age, sex, season, influenza diagnosis, and influenza vaccination status. RESULTS Mean age was 79.4 (standard deviation = 8.4) years; 53.1% were women. At baseline, 15.0% (n = 750) were nonfrail, 39.3% (n = 1971) were prefrail, 39.8% (n = 1995) were frail, and 5.9% (n = 295) were most frail. Poor recovery was experienced by 21.4%, 52.0% of whom had died. Frailty was associated with lower odds of recovery in all 3 seasons: 2011/2012 (odds ratio [OR] = 0.70; 95% confidence interval [CI], 0.59-0.84), 2012/2013 (OR = 0.72; 95% CI, 0.66-0.79), and 2013/2014 (OR = 0.75; 95% CI, 0.69-0.82); results varied by season, influenza status, vaccination status, and age. CONCLUSIONS Increasing frailty is associated with lower odds of recovery, and persistent worsening frailty is an important adverse outcome of acute illness.
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Affiliation(s)
- Caitlin Lees
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Judith Godin
- Geriatric Medicine Research, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Shelly A McNeil
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Loeb
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Todd F Hatchette
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jason LeBlanc
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Pathology and Laboratory Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - William Bowie
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Guy Boivin
- Centre Hospitalier Universitaire de Québec, Quebec City, Quebec, Canada
| | | | - André Poirier
- Centre Intégré Universitaire de Santé et Services Sociaux, Quebec City, Quebec, Canada
| | - Jeff Powis
- Michael Garron Hospital, Toronto, Ontario, Canada
| | | | - Duncan Webster
- Saint John Hospital Regional Hospital, Dalhousie University, New Brunswick, Canada
| | - Melissa K Andrew
- Geriatric Medicine Research, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
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14
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Mouratidou E, Lambrou A, Andreopoulou A, Gioula G, Exindari M, Kossyvakis A, Pogka V, Mentis A, Georgakopoulou T, Lytras T. Influenza vaccine effectiveness against hospitalization with laboratory-confirmed influenza in Greece: A pooled analysis across six seasons, 2013-2014 to 2018-2019. Vaccine 2020; 38:2715-2724. [PMID: 32033848 DOI: 10.1016/j.vaccine.2020.01.083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/24/2020] [Accepted: 01/27/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Monitoring seasonal influenza Vaccine Effectiveness (VE) is key to inform vaccination strategies and sustain uptake. Pooling data across multiple seasons increases precision and allows for subgroup analyses, providing more conclusive evidence. Our aim was to assess VE against hospitalization with laboratory-confirmed influenza in Greece over six seasons, from 2013 to 2014 to 2018-2019, using routinely collected surveillance data. METHODS Swab samples from hospitalized patients across the country were tested for influenza by RT-PCR. We used the test-negative design, with patients testing positive for influenza serving as cases and those testing negative serving as controls. VE was calculated as one minus the Odds Ratio (OR) for influenza vaccination, estimated by mixed-effects logistic regression and adjusted for age, sex, hospitalization type (being in intensive care or not), time from symptom onset to swabbing, and calendar time. Stratified estimates by age and hospitalization type were obtained, and also subgroup estimates by influenza type/subtype and season. Antigenic and genetic characterization of a subset of circulating influenza strains was performed. RESULTS A total of 3,882 test-positive cases and 5,895 test-negative controls were analyzed. Across all seasons, adjusted VE was 45.5% (95% CI: 31.6-56.6) against all influenza, 62.8% against A(H1N1)pdm09 (95% CI: 40.7-76.7), 28.2% against A(H3N2) (95% CI: 12.0-41.3) and 45.5% against influenza B (95% CI: 29.1-58.1). VE was slightly lower for patients aged 60 years and over, and similar between patients hospitalized inside or outside intensive care. Circulating A(H1N1)pdm09 and B strains were antigenically similar to the vaccine strains, whereas A(H3N2) were not. CONCLUSION Our results confirm the public health benefits from seasonal influenza vaccination, despite the suboptimal effectiveness against A(H3N2) strains. Continued monitoring of VE is essential, and routinely collected surveillance data can be valuable in this regard.
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Affiliation(s)
- Elisavet Mouratidou
- National Public Health Organization, Athens, Greece; European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
| | | | | | - Georgia Gioula
- National Influenza Centre for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Maria Exindari
- National Influenza Centre for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Athanasios Kossyvakis
- National Influenza Centre for Southern Greece, Hellenic Pasteur Institute, Athens, Greece
| | - Vasiliki Pogka
- National Influenza Centre for Southern Greece, Hellenic Pasteur Institute, Athens, Greece
| | - Andreas Mentis
- National Influenza Centre for Southern Greece, Hellenic Pasteur Institute, Athens, Greece
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15
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Influenza surveillance case definitions miss a substantial proportion of older adults hospitalized with laboratory-confirmed influenza: A report from the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS) Network. Infect Control Hosp Epidemiol 2020; 41:499-504. [PMID: 32146920 DOI: 10.1017/ice.2020.22] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Older adults often have atypical presentation of illness and are particularly vulnerable to influenza and its sequelae, making the validity of influenza case definitions particularly relevant. We sought to assess the performance of influenza-like illness (ILI) and severe acute respiratory illness (SARI) criteria in hospitalized older adults. DESIGN Prospective cohort study. SETTING The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network undertakes active surveillance for influenza among hospitalized adults. METHODS Data were pooled from 3 influenza seasons: 2011/12, 2012/13, and 2013/14. The ILI and SARI criteria were defined clinically, and influenza was laboratory confirmed. Frailty was measured using a validated frailty index. RESULTS Of 11,379 adult inpatients (7,254 aged ≥65 years), 4,942 (2,948 aged ≥65 years) had laboratory-confirmed influenza. Their median age was 72 years (interquartile range [IQR], 58-82) and 52.6% were women. The sensitivity of ILI criteria was 51.1% (95% confidence interval [CI], 49.6-52.6) for younger adults versus 44.6% (95% CI, 43.6-45.8) for older adults. SARI criteria were met by 64.1% (95% CI, 62.7-65.6) of younger adults versus 57.1% (95% CI, 55.9-58.2) of older adults with laboratory-confirmed influenza. Patients with influenza who were prefrail or frail were less likely to meet ILI and SARI case definitions. CONCLUSIONS A substantial proportion of older adults, particularly those who are frail, are missed by standard ILI and SARI case definitions. Surveillance using these case definitions is biased toward identifying younger cases, and does not capture the true burden of influenza. Because of the substantial fraction of cases missed, surveillance definitions should not be used to guide diagnosis and clinical management of influenza.
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16
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LeBlanc JJ, ElSherif M, Mulpuru S, Warhuus M, Ambrose A, Andrew M, Boivin G, Bowie W, Chit A, Dos Santos G, Green K, Halperin SA, Hatchette TF, Ibarguchi B, Johnstone J, Katz K, Langley JM, Lagacé-Wiens P, Loeb M, Lund A, MacKinnon-Cameron D, McCarthy A, McElhaney JE, McGeer A, Poirier A, Powis J, Richardson D, Semret M, Shinde V, Smyth D, Trottier S, Valiquette L, Webster D, Ye L, McNeil S. Validation of the Seegene RV15 multiplex PCR for the detection of influenza A subtypes and influenza B lineages during national influenza surveillance in hospitalized adults. J Med Microbiol 2020; 69:256-264. [PMID: 31264957 PMCID: PMC7431100 DOI: 10.1099/jmm.0.001032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/16/2019] [Indexed: 01/04/2023] Open
Abstract
Background. The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) has been performing active influenza surveillance since 2009 (ClinicalTrials.gov identifier: NCT01517191). Influenza A and B viruses are identified and characterized using real-time reverse-transcriptase polymerase chain reaction (RT-PCR), and multiplex testing has been performed on a subset of patients to identify other respiratory virus aetiologies. Since both methods can identify influenza A and B, a direct comparison was performed.Methods. Validated real-time RT-PCRs from the World Health Organization (WHO) to identify influenza A and B viruses, characterize influenza A viruses into the H1N1 or H3N2 subtypes and describe influenza B viruses belonging to the Yamagata or Victoria lineages. In a subset of patients, the Seeplex RV15 One-Step ACE Detection assay (RV15) kit was also used for the detection of other respiratory viruses.Results. In total, 1111 nasopharyngeal swabs were tested by RV15 and real-time RT-PCRs for influenza A and B identification and characterization. For influenza A, RV15 showed 98.0 % sensitivity, 100 % specificity and 99.7 % accuracy. The performance characteristics of RV15 were similar for influenza A subtypes H1N1 and H3N2. For influenza B, RV15 had 99.2 % sensitivity, 100 % specificity and 99.8 % accuracy, with similar assay performance being shown for both the Yamagata and Victoria lineages.Conclusions. Overall, the detection of circulating subtypes of influenza A and lineages of influenza B by RV15 was similar to detection by real-time RT-PCR. Multiplex testing with RV15 allows for a more comprehensive respiratory virus surveillance in hospitalized adults, without significantly compromising the reliability of influenza A or B virus detection.
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Affiliation(s)
- J. J. LeBlanc
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - M. ElSherif
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - S. Mulpuru
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - M. Warhuus
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - A. Ambrose
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - M. Andrew
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - G. Boivin
- Centre Hospitalier Universitaire de Québec, QC, Canada
| | - W. Bowie
- University of British Columbia, Vancouver, BC, Canada
| | - A. Chit
- Sanofi Pasteur, Swiftwater, PA, USA
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - G. Dos Santos
- Business & Decision Life Sciences (on behalf of GSK), Bruxelles, Belgium
- Present address: GSK, Wavre, Belgium
| | - K. Green
- Mount Sinai Hospital, Toronto, ON, Canada
| | - S. A. Halperin
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - T. F. Hatchette
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - B. Ibarguchi
- GSK, Mississauga, ON, Canada
- Present address: Bayer, Inc., Mississauga, Ontario, Canada
| | - J. Johnstone
- Public Health Ontario and University of Toronto, Toronto, ON, Canada
| | - K. Katz
- North York General Hospital, Toronto, ON, Canada
| | - J. M. Langley
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | | | - M. Loeb
- Public Health Ontario and University of Toronto, Toronto, ON, Canada
| | - A. Lund
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - D. MacKinnon-Cameron
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - A. McCarthy
- Ottawa Hospital General, Ottawa, Ontario, Canada
| | - J. E. McElhaney
- Health Sciences North Research Institute, Sudbury, ON, Canada
| | - A. McGeer
- Mount Sinai Hospital, Toronto, ON, Canada
| | - A. Poirier
- Centre Intégré Universitaire de Santé et Services Sociaux, Quebec, QC, Canada
| | - J. Powis
- Toronto East General Hospital, Toronto, ON, Canada
| | | | - M. Semret
- McGill University, Montreal, QC, Canada
| | - V. Shinde
- GSK, King of Prussia, PA, USA
- Present address: Novavax Vaccines, Washington, DC, USA
| | - D. Smyth
- The Moncton Hospital, Moncton, NB, Canada
| | - S. Trottier
- Centre Hospitalier Universitaire de Québec, QC, Canada
| | | | | | - L. Ye
- Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre, and Nova Scotia Health Authority, Halifax, NS, Canada
| | - S. A. McNeil
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
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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: 88] [Impact Index Per Article: 22.0] [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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18
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Andrew MK, Bowles SK, Pawelec G, Haynes L, Kuchel GA, McNeil SA, McElhaney JE. Influenza Vaccination in Older Adults: Recent Innovations and Practical Applications. Drugs Aging 2019; 36:29-37. [PMID: 30411283 DOI: 10.1007/s40266-018-0597-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Influenza can lead to serious illness, particularly for older adults. In addition to short-term morbidity and mortality during the acute infection, recovery can be prolonged and often incomplete. This may lead to persistent declines in health and function, including catastrophic disability, which has dramatic implications for the well-being and support needs of older adults and their caregivers. All of this means that prevention of infection and effective treatment when illness has occurred are of paramount importance. In this narrative review, we discuss the effectiveness of influenza vaccines for the prevention of influenza illness and serious outcomes in older adults. We review evidence of vaccine effectiveness for older adults in comparison with younger age groups, and also highlight the importance of frailty as a determinant of vaccine effectiveness. We then turn our attention to the question of why older and frailer individuals have poorer vaccine responses, and consider changes in immune function and inflammatory responses. This sets the stage for a discussion of newer influenza vaccine products that have been developed with the aim of enhancing vaccine effectiveness in older adults. We review the available evidence on vaccine efficacy, effectiveness and cost benefits, consider the potential place of these innovations in clinical geriatric practice, and discuss international advisory committee recommendations on influenza vaccination in older adults. Finally, we highlight the importance of influenza prevention to support healthy aging, along with the need to improve vaccine coverage rates using available vaccine products, and to spur development of better influenza vaccines for older adults in the near future.
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Affiliation(s)
- Melissa K Andrew
- Division of Geriatric Medicine, Department of Medicine (Geriatrics), Dalhousie University, 5955 Veterans' Memorial Lane, Halifax, NS, Canada. .,Canadian Center for Vaccinology, Halifax, NS, Canada.
| | - Susan K Bowles
- Division of Geriatric Medicine, Department of Medicine (Geriatrics), Dalhousie University, 5955 Veterans' Memorial Lane, Halifax, NS, Canada.,Canadian Center for Vaccinology, Halifax, NS, Canada.,Department of Pharmacy, Nova Scotia Health Authority, Central Zone, Halifax, NS, Canada
| | - Graham Pawelec
- Second Department of Internal Medicine, University of Tübingen, Tübingen, Germany.,Health Sciences North Research Institute, Sudbury, ON, Canada
| | - Laura Haynes
- Center on Aging, University of Connecticut School of Medicine, Farmington, CT, USA
| | - George A Kuchel
- Center on Aging, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Shelly A McNeil
- Canadian Center for Vaccinology, Halifax, NS, Canada.,Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, NS, Canada
| | - Janet E McElhaney
- Health Sciences North Research Institute, Northern Ontario School of Medicine, Sudbury, ON, Canada
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19
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Transmissibility and severity of influenza virus by subtype. INFECTION GENETICS AND EVOLUTION 2018; 65:288-292. [PMID: 30103034 DOI: 10.1016/j.meegid.2018.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/21/2018] [Accepted: 08/09/2018] [Indexed: 11/21/2022]
Abstract
The characteristics of influenza might vary depending on the disease subtype. This review includes previous studies on the transmissibility and severity of influenza and summarizes them by subtype. The attack rate and incubation period of influenza A were 2.3-12.3% and 1.4 days, respectively, and those of influenza B were 0.6-5.5% and 0.6 days, respectively. The five subtypes of influenza A virus, namely, H1N1, H2N2, H3N3, H5N1, and H7N9, are reviewed. The indexes related to transmissibility (reproduction number, attack rate, serial interval, latent period, incubation period, infectious period) and severity (hospitalization rate, case fatality rate) differed by influenza subtype. Generally, H3N2 showed a higher attack rate than H1N1 and H2N2. Additionally, H5N1 and H7N9 showed higher mortality rates than the other subtypes, including H1N1, H2N2, H3N2.
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20
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van Someren Gréve F, van der Sluijs KF, Tuip AM, Schultz MJ, de Jong MD, Juffermans NP. Treatment with broadly neutralizing influenza antibodies reduces severity of secondary pneumococcal pneumonia in mice. J Med Virol 2018; 90:1431-1437. [PMID: 29718555 PMCID: PMC6055667 DOI: 10.1002/jmv.25212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/21/2018] [Indexed: 12/27/2022]
Abstract
Secondary bacterial pneumonia is a frequent complication of influenza, associated with high morbidity and mortality. We hypothesized that treatment with neutralizing influenza A antibody AT10_002 protects against severe secondary pneumococcal infection in a mouse model of influenza A infection. Influenza A (H3N2) virus–infected male C57Bl6 mice were treated intravenously with either AT10_002 or a control 2 days postinfection. Seven days later, both groups were infected with Streptococcus pneumoniae and killed 18 hours later. Mice receiving AT10_002 showed less loss of bodyweight compared with controls (+1% vs −12%, P < .001), lower viral loads in bronchoalveolar lavage fluids (BALFs) (7 vs 194 RNA copies per µL; P < .001), and reduced bacterial outgrowth in lung homogenates (3.3 × 101 vs 2.5 × 105 colony‐forming units per mg; P < .001). The treatment group showed lower pulmonary wet weights, lower cell counts, and lower protein levels in BALF compared with controls. Treatment with AT10_002 was associated with lower levels of tumor necrosis factor‐α, interleukin (IL)‐6, cytokine‐induced neutrophil chemoattractant (KC), and interferon‐γ in BALF and lower IL‐6 and KC in lung homogenates. Treatment with anti‐influenza antibody AT10_002 is associated with reduced weight loss, viral load, bacterial outgrowth, and lung injury in a murine model of secondary pneumococcal pneumonia following influenza infection.
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Affiliation(s)
- Frank van Someren Gréve
- Department of Intensive Care, Academic Medical Center, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, The Netherlands.,Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Koenraad F van der Sluijs
- Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, The Netherlands
| | - Anita M Tuip
- Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, The Netherlands
| | - Marcus J Schultz
- Department of Intensive Care, Academic Medical Center, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, The Netherlands.,Faculty of Tropical Medicine, Mahidol Oxford Research Unit (MORU), Mahidol University, Bangkok, Thailand
| | - Menno D de Jong
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Nicole P Juffermans
- Department of Intensive Care, Academic Medical Center, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, The Netherlands
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21
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Nichols MK, Andrew MK, Hatchette TF, Ambrose A, Boivin G, Bowie W, Chit A, Dos Santos G, ElSherif M, Green K, Haguinet F, Halperin SA, Ibarguchi B, Johnstone J, Katz K, Lagacé-Wiens P, Langley JM, LeBlanc J, Loeb M, MacKinnon-Cameron D, McCarthy A, McElhaney JE, McGeer A, Poirier A, Powis J, Richardson D, Schuind A, Semret M, Shinde V, Smith S, Smyth D, Stiver G, Taylor G, Trottier S, Valiquette L, Webster D, Ye L, McNeil SA. Influenza vaccine effectiveness to prevent influenza-related hospitalizations and serious outcomes in Canadian adults over the 2011/12 through 2013/14 influenza seasons: A pooled analysis from the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS Network). Vaccine 2018; 36:2166-2175. [PMID: 29548608 DOI: 10.1016/j.vaccine.2018.02.093] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Ongoing assessment of influenza vaccine effectiveness (VE) is critical to inform public health policy. This study aimed to determine the VE of trivalent influenza vaccine (TIV) for preventing influenza-related hospitalizations and other serious outcomes over three consecutive influenza seasons. METHODS The Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research Network (CIRN) conducted active surveillance for influenza in adults ≥16 years (y) of age during the 2011/2012, 2012/2013 and 2013/2014 seasons in hospitals across Canada. A test-negative design was employed: cases were polymerase chain reaction (PCR)-positive for influenza; controls were PCR-negative for influenza and were matched to cases by date, admission site, and age (≥65 y or <65 y). All cases and controls had demographic and clinical characteristics (including influenza immunization status) obtained from the medical record. VE was estimated as 1-OR (odds ratio) in vaccinated vs. unvaccinated patients × 100%. The primary outcome was VE of TIV for preventing laboratory-confirmed influenza-related hospitalization; secondary outcomes included VE of TIV for preventing influenza-related intensive care unit (ICU) admission/mechanical ventilation, and influenza-related death. RESULTS Overall, 3394 cases and 4560 controls were enrolled; 2078 (61.2%) cases and 2939 (64.5%) controls were ≥65 y. Overall matched, adjusted VE was 41.7% (95% Confidence Interval (CI): 34.4-48.3%); corresponding VE in adults ≥65 y was 39.3% (95% CI: 29.4-47.8%) and 48.0% (95% CI: 37.5-56.7%) in adults <65 y, respectively. VE for preventing influenza-related ICU admission/mechanical ventilation in all ages was 54.1% (95% CI: 39.8-65.0%); in adults ≥65 y, VE for preventing influenza-related death was 74.5% (95% CI: 44.0-88.4%). CONCLUSIONS While effectiveness of TIV to prevent serious outcomes varies year to year, we demonstrate a statistically significant and clinically important TIV VE for preventing hospitalization and other serious outcomes over three seasons. Public health messaging should highlight the overall benefit of influenza vaccines over time while acknowledging year to year variability. ClinicalTrials.gov Identifier: NCT01517191.
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Affiliation(s)
- Michaela K Nichols
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Melissa K Andrew
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Todd F Hatchette
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ardith Ambrose
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Guy Boivin
- Centre Hospitalier Universitaire de Québec, Québec, Québec, Canada
| | - William Bowie
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Ayman Chit
- Sanofi Pasteur, Swiftwater, PA, USA; Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | | | - May ElSherif
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Karen Green
- Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - Scott A Halperin
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | - Kevin Katz
- North York General Hospital, Toronto, Ontario, Canada
| | | | - Joanne M Langley
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jason LeBlanc
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Loeb
- McMaster University, Hamilton, Ontario, Canada
| | - Donna MacKinnon-Cameron
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | | | - Andre Poirier
- Centre Intégré Universitaire de santé et services sociaux, Quebec, Quebec, Canada
| | - Jeff Powis
- Michael Garron Hospital, Toronto, Ontario, Canada
| | | | | | | | | | | | - Daniel Smyth
- The Moncton Hospital, Moncton, New Brunswick, Canada
| | - Grant Stiver
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Sylvie Trottier
- Centre Hospitalier Universitaire de Québec, Québec, Québec, Canada
| | | | | | - Lingyun Ye
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shelly A McNeil
- Canadian Center for Vaccinology, IWK Health Centre and Nova Scotia Health Authority, Dalhousie University, Halifax, Nova Scotia, Canada.
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