Influenza vaccine effectiveness among high-risk groups: A systematic literature review and meta-analysis of case-control and cohort studies

Human Vaccines and Immunotherapeutics

Volumn 14, Issue 3, 2018, Pages 724-735

  Restivo, Vincenzo ^a   Costantino, Claudio ^a   Bono, Stefania ^a   Maniglia, Marialuisa ^a   Marchese, Valentina ^a   Ventura, Gianmarco ^a   Casuccio, Alessandra ^a   Tramuto, Fabio ^a   Vitale, Francesco ^a  

^a UNIVERSITY OF PALERMO   (Italy)

Author keywords

children; chronic disease; effectiveness; elderly subjects; health care worker; hospitalization; influenza; pregnancy; vaccine; visit

Indexed keywords

INFLUENZA VACCINE;

CASE CONTROL STUDY; CLINICAL DECISION MAKING; COHORT ANALYSIS; DEATH; HEALTH CARE PERSONNEL; HIGH RISK POPULATION; HOSPITALIZATION; HUMAN; INFLUENZA; INFLUENZA A (H1N1); META ANALYSIS; NONHUMAN; PNEUMONIA; PREGNANT WOMAN; QUALITATIVE ANALYSIS; RESPIRATORY TRACT INFECTION; REVIEW; SEASONAL INFLUENZA; SYSTEMATIC REVIEW; VACCINATION; ADOLESCENT; ADULT; AGED; CHILD; FEMALE; IMMUNOLOGY; INFANT; MIDDLE AGED; PREGNANCY; PRESCHOOL CHILD; PROCEDURES; RISK; VERY ELDERLY; YOUNG ADULT;

ADOLESCENT; ADULT; AGED; AGED, 80 AND OVER; CASE-CONTROL STUDIES; CHILD; CHILD, PRESCHOOL; COHORT STUDIES; FEMALE; HOSPITALIZATION; HUMANS; INFANT; INFLUENZA VACCINES; INFLUENZA, HUMAN; MIDDLE AGED; PREGNANCY; RISK; VACCINATION; YOUNG ADULT;

EID: 85044247805     PISSN: 21645515     EISSN: 2164554X     Source Type: Journal    
DOI: 10.1080/21645515.2017.1321722     Document Type: Review

References (87)

1. Molinari NA, Ortega-Sanchez IR, Messonnier ML, Thompson WW, Wortley PM, Weintraub E, Bridges CB. The annual impact of seasonal influenza in the US: measuring disease burden and costs. Vaccine 2007; 25(27):5086-96; PMID:17544181; https://doi.org/10.1016/j.vaccine.2007.03.046
2. Bonmarin I, Belchior E, Lévy-Bruhl D. Impact of influenza vaccination on mortality in the French elderly population during the 2000–2009 period. Vaccine 2015; 33(9):1099-1101; PMID:25604800; https://doi.org/10.1016/j.vaccine.2015.01.023
3. Molbak K, Espenhain L, Nielsen J, Tersago K, Bossuyt N, Denissov G, Baburin A, Virtanen M, Fouillet A, Sideroglou T, et al. Excess mortality among the elderly in European countries, December 2014 to February 2015. Euro Surveill 2015; 20(11);pii:2106; https://doi.org/10.2807/1560-7917.ES2015.20.11.21065
4. Mazick A, Gergonne B, Nielsen J, Wuillaume F, Virtanen MJ, Fouillet A, Uphoff H, Sideroglou T, Paldy A, Oza A, et al. Excess mortality among the elderly in 12 European countries, February and March 2012. Euro Surveill 2012; 17(14);pii:20138
5. Michelozzi P, De' Donato F, Scortichini M, De Sario M, Asta F, Agabiti N, Guerra R, De Martino A, Davoli M. On the increase in mortality in Italy in 2015: analysis of seasonal mortality in the 32 municipalities included in the Surveillance system of daily mortality. Epidemiol Prev 2016; 40(1):22-8; PMID:26951698
6. Matias G, Taylor R, Haguinet F, Schuck-Paim C, Lustig R, Shinde V. Estimates of mortality attributable to influenza and RSV in the United States during 1997–2009 by influenza type or subtype, age, cause of death, and risk status. Influenza Other Respir Viruses 2014; 8(5):507-15; PMID:24975705; https://doi.org/10.1111/irv.12258
7. Fischer WA, Gongz M, Bhagwanjeex S, Sevransky J. Global Burden of Influenza as a Cause of Cardiopulmonary Morbidity and Mortality. Global hearth 2014; 3:325-36; https://doi.org/10.1016/j.gheart.2014.08.004
8. Beck CR, McKenzie BC, Hashim AB. Influenza Vaccination for Immunocompromised Patients: Systematic Review and Meta-analysis by Etiology. J Infect Dis 2012; 206:1250-9; PMID:22904335; https://doi.org/10.1093/infdis/jis487
9. Louie JK, Acosta M, Jamieson DJ, Honein MA. Severe 2009 H1N1 Influenza in Pregnant and Postpartum Women in California. N Engl J Med 2010; 362:27-35; PMID:20032319; https://doi.org/10.1056/NEJMoa0910444
10. Principi N, Esposito S, Marchisio P, Gasparini R, Crovari P. Socioeconomic impact of influenza on healthy children and their families. Pediatr Infect Dis J 2003; 22:S207-10; PMID:14551476; https://doi.org/10.1097/01.inf.0000092188.48726.e4
11. McLean HQ, Peterson SH, King JP, Meece JK, Belongia EA. School absenteeism among school-aged children with medically attended acute viral respiratory illness during three influenza seasons, 2012–2013 through 2014–2015. Influenza Other Respir Viruses 2017; 11(3):220-229; https://doi.org/10.1111/irv.12440
12. Amodio E, Restivo V, Firenze A, Mammina C, Tramuto F, Vitale F. Can influenza vaccination coverage among healthcare workers influence the risk of nosocomial influenza-like illness in hospitalized patients? J Hosp Infect 2014; 86(3):182-7; PMID:24581755; https://doi.org/10.1016/j.jhin.2014.01.005
13. Elder AG, O'Donnell B, McCruden EAB, Symington IS, Carman WF. Incidence and recall of influenza in a cohort of Glasgow healthcare workers during the 1993–4 epidemic: results of serum testing and questionnaire. BMJ 1996; 313:1241-2; https://doi.org/10.1136/bmj.313.7067.1241
14. Restivo V, Costantino C, Mammina C, Vitale F. Influenza like Illness among medical residents anticipates influenza diffusion in general population: data from a national survey among Italian medical residents. PLoS One 2016; 11(12):e0168546; PMID:27997602; https://doi.org/10.1371/journal.pone.0168546
15. Hagel S, Ludewig K, Moeser A, Baier M, Löffler B, Schleenvoigt B, Forstner C, Pletz MW. Characteristics and management of patients with influenza in a German hospital during the 2014/2015 influenza season. Infection 2016; 44(5):667-72; PMID:27380386; https://doi.org/10.1007/s15010-016-0920-0
16. Dolan GP, Harris RC, Clarkson M, Sokal R, Morgan G, Mukaigawara M, Horiuchi H, Hale R, Stormont L, Béchard-Evans L, et al. Vaccination of health care workers to protect patients at increased risk for acute respiratory disease. Emerg Infect Dis 2012; 18(8):1225-34; PMID:22840895; https://doi.org/10.3201/eid1808.111355
17. Costantino C, Vitale F. Influenza vaccination in high-risk groups: a revision of existing guidelines and rationale for an evidence-based preventive strategy. J Prev Med Hyg 2016; 57(1):E13-8; PMID:27346934
18. Grohskopf LA, Sokolow LZ, Broder KR, Olsen SJ, Karron RA, Jernigan DB, Bresee JS. Prevention and control of seasonal influenza with vaccines. MMWR Recomm Rep 2016; 65(5):1-54; https://doi.org/10.15585/mmwr.rr6505a1
19. Armstrong C. ACIP Updates Influenza Vaccination Recommendations for 2016–2017. Am Fam Physician 2016; 94(8):668-70; PMID:27929223
20. Doherty M, Schmidt-Ott R, Santos JI, Stanberry LR, Hofstetter AM, Rosenthal SL, Cunningham AL. Vaccination of special populations: Protecting the vulnerable. Vaccine 2016; 34(52):6681-90; PMID:27876197; https://doi.org/10.1016/j.vaccine.2016.11.015
21. European Centre for Disease Prevention and Control. Seasonal influenza vaccines. Influenza vaccination. [Accessed 2017Februaty22] http://ecdc.europa.eu/en/healthtopics/seasonal_influenza/vaccines/Pages/influenza_vaccination.aspx#vaccinationstrategies
22. Szilagyi PG, Fairbrother G, Griffin MR, Hornung RW, Donauer S, Morrow A, Altaye M, Zhu Y, Ambrose S, Edwards KM, et al. Influenza vaccine effectiveness among children 6 to 59 months of age during 2 influenza seasons: a case-cohort study. Arch Pediatr Adolesc Med 2008; 162(10):943-51; PMID:18838647; https://doi.org/10.1001/archpedi.162.10.943
23. Ridenhour BJ, Campitelli MA, Kwong JC, Rosella LC, Armstrong BG, Mangtani P, Calzavara AJ, Shay DK. Effectiveness of inactivated influenza vaccines in preventing influenza-associated deaths and hospitalizations among Ontario residents aged ≥ 65 years: estimates with generalized linear models accounting for healthy vaccinee effects. PLoS One 2013; 8(10):e76318; PMID:24146855; https://doi.org/10.1371/journal.pone.0076318
24. Cheng AC, Kotsimbos T, Kelly PM, FluCAN Investigators. Influenza vaccine effectiveness against hospitalisation with influenza in adults in Australia in 2014. Vaccine 2015; 33(51):7352-6; PMID:26529066; https://doi.org/10.1016/j.vaccine.2015.10.016
25. MacIntyre CR, Heywood AE, Kovoor P, Ridda I, Seale H, Tan T, Gao Z, Katelaris AL, Siu HW, Lo V, et al. I schaemic heart disease, influenza and influenza vaccination: a prospective case control study. Heart 2013; 99(24):1843-8; PMID:23966030; https://doi.org/10.1136/heartjnl-2013-304320
26. Puig-Barberà J, Díez-Domingo J, Arnedo-Pena A, Ruiz-García M, Pérez-Vilar S, Micó-Esparza JL, Belenguer-Varea A, Carratalá-Munuera C, Gil-Guillén V, Schwarz-Chavarri H. Effectiveness of the 2010–2011 seasonal influenza vaccine in preventing confirmed influenza hospitalizations in adults: a case-case comparison, case-control study. Vaccine 2012; 30(39):5714-20; PMID:22819720; https://doi.org/10.1016/j.vaccine.2012.07.006
27. Steens A, Wijnans EG, Dieleman JP, Sturkenboom MC, van der Sande MA, van der Hoek W. Effectiveness of a MF-59™-adjuvanted pandemic influenza vaccine to prevent 2009 A/H1N1 influenza-related hospitalisation; a matched case-control study. BMC Infect Dis 2011; 11:196; PMID:21767348; https://doi.org/10.1186/1471-2334-11-196
28. Andrews N, Waight P, Yung CF, Miller E. Age-specific effectiveness of an oil-in-water adjuvanted pandemic (H1N1) 2009 vaccine against confirmed infection in high risk groups in England. J Infect Dis 2011; 203(1):32-9; PMID:21148494; https://doi.org/10.1093/infdis/jiq014
29. Emborg HD, Krause TG, Hviid A, Simonsen J, Mølbak K. Effectiveness of vaccine against pandemic influenza A/H1N1 among people with underlying chronic diseases: cohort study, Denmark, 2009–10. BMJ 2011; 344:d7901; PMID:22277542; https://doi.org/10.1136/bmj.d7901
30. Perez-Romero P, Aydillo TA, Perez-Ordoñez A, Muñoz P, Moreno A, López-Medrano F, Bodro M, Montejo M, Gavaldà J, Fariñas MC, et al. Reduced incidence of pneumonia in influenza-vaccinated solid organ transplant recipients with influenza disease. Clin Microbiol Infect 2012; 18(12):E533-40; PMID:23078072; https://doi.org/10.1111/1469-0691.12044
31. Thompson MG, Li DK, Shifflett P, Sokolow LZ, Ferber JR, Kurosky S, Bozeman S, Reynolds SB, Odouli R, Henninger ML, et al. Effectiveness of seasonal trivalent influenza vaccine for preventing influenza virus illness among pregnant women: a population-based case-control study during the 2010–2011 and 2011–2012 influenza seasons. Clin Infect Dis 2014; 58(4):449-57; PMID:24280090; https://doi.org/10.1093/cid/cit750
32. Regan AK, Klerk, Nd, Moore HC, Omer SB, Shellam G, Effler PV. Effectiveness of seasonal trivalent influenza vaccination against hospital-attended acute respiratory infections in pregnant women: A retrospective cohort study. Vaccine 2016; 34(32):3649-56; PMID:27216758; https://doi.org/10.1016/j.vaccine.2016.05.032
33. Costa JT, Silva R, Tavares M, Nienhaus A. High effectiveness of pandemic influenza A (H1N1) vaccination in healthcare workers from a Portuguese hospital. Int Arch Occup Environ Health 2012; 85(7):747-52; PMID:22045387; https://doi.org/10.1007/s00420-011-0714-8
34. Igari H, Watanabe A, Chiba H, Shoji K, Segawa S, Nakamura Y, Watanabe M, Suzuki K, Sato T. Effectiveness and safety of pandemic influenza A (H1N1) 2009 vaccine in healthcare workers at a university hospital in Japan. Jpn J Infect Dis 2011; 64(3):177-82; PMID:21617299
35. World Health Organization. Vaccines against influenza WHO position paper–November 2012. Wkly Epidemiol Rec 2012; 87(47):461-76; PMID:23210147
36. Remschmidt C, Wichmann O, Harder T. Influenza vaccination in patients with end-stage renal disease: systematic review and assessment of quality of evidence related to vaccine efficacy, effectiveness, and safety. BMC Med 2014; 12:244; PMID:25523432; https://doi.org/10.1186/s12916-014-0244-9
37. Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev 2012; 15(8):CD004879; PMID:22895945
38. Vu T, Farish S, Jenkins M, Kelly H. A meta-analysis of effectiveness of influenza vaccine in persons aged 65 years and over living in the community. Vaccine 2002; 20(13–14):1831-6; PMID:11906772; https://doi.org/10.1016/S0264-410X(02)00041-5
39. European Centre for Disease Prevention and Control. Seasonal influenza vaccination in Europe: Overview of vaccination recommendations and coverage rates in the EU Member States for the 2012–13 influenza season. [Accessed 2017February22] http://ecdc.europa.eu/en/publications/Publications/Seasonal-influenza-vaccination-Europe-2012-13.pdf
40. Sung LC, Chen CI, Fang YA, Lai CH, Hsu YP, Cheng TH, Miser JS, Liu JC. Influenza vaccination reduces hospitalization for acute coronary syndrome in elderly patients with chronic obstructive pulmonary disease: a population-based cohort study. Vaccine 2014; 32(30):3843-9; PMID:24837769; https://doi.org/10.1016/j.vaccine.2014.04.064
41. Restivo V, Vizzini G, Mularoni A, Di Benedetto C, Gioè SM, Vitale F. Determinants of influenza vaccination among solid organ transplant recipients attending Sicilian reference center. Hum Vaccin Immunother 2017; 13(2):346-50; PMID:27929758; https://doi.org/10.1080/21645515.2017.1264792
42. Rasmussen SA, Jamieson DJ, Bresee S. Pandemic influenza and pregnant women. Emerg Infect Dis 2008; 14:95-100; PMID:18258087; https://doi.org/10.3201/eid1401.070667
43. Nandor ACS, Banhidy F, Puho E, Czeizel AE. Maternal influenza during pregnancy and risk of congenital abnormalities in offspring. Birth Def Res 2005; 73:989-96; https://doi.org/10.1002/bdra.20195
44. Radigan KA, Mutlu GM. Markers of prognosis specific to influenza infection: are we there yet? Am J Respir Crit Care Med 2014; 189(10):1159-60; PMID:24832741; https://doi.org/10.1164/rccm.201403-0587ED
45. Kidd M. Influenza viruses: update on epidemiology, clinical features, treatment and vaccination. Curr Opin Pulm Med 2014; 20:242-6; PMID:24637227; https://doi.org/10.1097/MCP.0000000000000049
46. Nair H, Brooks WA, Katz M, Roca A, Berkley JA, Madhi SA, Simmerman JM, Gordon A, Sato M, Howie S, et al. Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis. Lancet 2011; 378(9807):191; https://doi.org/10.1016/S0140-6736(11)61051-9
47. Lafond KE, Nair H, Rasooly MH, Valente F, Booy R, Rahman M, Kitsutani P, Yu H, Guzman G, Coulibaly D, et al. Global role and burden of influenza in pediatric respiratory hospitalizations, 1982–2012: a systematic analysis. PLoS Med 2016; 13(3):e1001977; PMID:27011229; https://doi.org/10.1371/journal.pmed.1001977
48. Sullivan SG, Chilver MB, Higgins G, Cheng AC, Stocks NP. Influenza vaccine effectiveness in Australia: results from the Australian Sentinel Practices Research Network. Med J Aust 2014; 201(2):109-11; PMID:25045991
49. Irving SA, Donahue JG, Shay DK, Ellis-Coyle TL, Belongia EA. Evaluation of self-reported and registry-based influenza vaccination status in a Wisconsin cohort. Vaccine 2009; 27(47):6546-9; PMID:19729083
50. Eisenberg KW, Szilagyi PG, Fairbrother G, Griffin MR, Staat M, Shone LP, Weinberg GA, Hall CB, Poehling KA, Edwards KM, et al. Vaccine effectiveness against laboratory-confirmed influenza in children 6 to 59 months of age during the 2003–2004 and 2004–2005 influenza seasons. Pediatrics 2008; 122(5):911-9; PMID:18977968
51. Centers for Disease Control and Prevention. Update: influenza activity: United States and worldwide, 2003–04 season, and composition of the 2004–05 influenza vaccine. MMWR Morb Mortal Wkly Rep 2004; 53(25):547-52; PMID:15229411
52. Centers for Disease Control and Prevention. Update: influenza activity: United States and worldwide, 2004–05 season. MMWR Morb Mortal Wkly Rep 2005; 54(25):631-4; PMID:15988408
53. Dixon GA, Moore HC, Kelly H, Jacoby P, Carcione D, Williams S, Smith D, Keil AD, Van Buynder P, Richmond PC, et al. Lessons from the first year of the WAIVE study investigating the protective effect of influenza vaccine against laboratory-confirmed influenza in hospitalised children aged 6–59 months. Influenza Other Respir Viruses 2010; 4(4):231-4; PMID:20629773
54. Blyth CC, Cheng AC, Finucane C, Jacoby P, Effler PV, Smith DW, Kelly H, Macartney KK, Richmond PC. The effectiveness of influenza vaccination in preventing hospitalisation in children in Western Australia. Vaccine 2015; 33(51):7239-44; PMID:26549359
55. Sanei F, Wilkinson T. Influenza vaccination for patients with chronic obstructive pulmonary disease: understanding immunogenicity, efficacy and effectiveness. Ther Adv Respir Dis 2016; 10(4):349-67; PMID:27193567
56. Kim JH, Skountzou I, Compans R, Jacob J. Original antigenic sin responses to influenza viruses. J Immunol 2009; 183(5):3294-301; PMID:19648276
57. Centers for Disease Control and Prevention. Update: influenza activity–United States and worldwide, May 19-September 28, 2013. MMWR Morb Mortal Wkly Rep 2013; 62:838-42; PMID:24153315
58. Smith DJ, Forrest S, Ackley DH, Perelson AS. Variable efficacy of repeated annual influenza vaccination. Proc Natl Acad Sci U S A 1999; 96:14001-6; PMID:10570188
59. Orellano PW, Reynoso JI, Carlino O, Uez O. Protection of trivalent inactivated influenza vaccine against hospitalizations among pandemic influenza A (H1N1) cases in Argentina. Vaccine 2010; 28(32):5288-91
60. Gilca R, Skowronski DM, Douville-Fradet M, Amini R, Boulianne N, Rouleau I, Martineau C, Charest H, De Serres G. Mid-Season estimates of influenza vaccine effectiveness against influenza A(H3N2) hospitalization in the elderly in Quebec, Canada, January 2015. PLoS One 2015; 10(7):e0132195; PMID:26200655
61. Chambers BS, Parkhouse K, Ross TM, Alby K, Hensley SE. Identification of hemagglutinin residues responsible for H3N2 antigenic drift during the 2014–2015 influenza season. Cell Rep 2015; 12(1):1-6; PMID:26119736
62. Higgins JP, Green S. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.handbook.cochrane.org
63. Jackson ML, Nelson JC. The test-negative design for estimating influenza vaccine effectiveness. Vaccine 2013; 31(17):2165-8; PMID:23499601
64. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials 1986; 7:177-88; PMID:3802833; https://doi.org/10.1016/0197-2456(86)90046-2
65. Fleiss JL. The statistical basis of meta-analysis. Stat Methods Med Res 1993; 2:121-45; PMID:8261254; https://doi.org/10.1177/096228029300200202
66. Higgins JPT, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ Br Med J 2003; 327:557-60; https://doi.org/10.1136/bmj.327.7414.557
67. Wells GA, Shea B, O'Connell D, Peterson J, Welch V, Losos M, Tugwell P. The Newcastle-Ottawa Scale (NOS) for assessing the quality if nonrandomized studies in meta-analyses. 2012. [Accessed 2017february22]. http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp
68. Sterne JA, Egger M. Funnel plots for detecting bias in metaanalysis: Guidelines on choice of axis. J Clin Epidemiol 2001; 54:1046-55; PMID:11576817; https://doi.org/10.1016/S0895-4356(01)00377-8
69. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997; 315:629-34; PMID:9310563; https://doi.org/10.1136/bmj.315.7109.629
70. Palmer TM, Sterne JA, editors. Meta-Analysis in Stata: An Updated Collection from the Stata Journal. 2nd ed. Stata Press; 2015, 534 p
71. Blyth CC, Jacoby P, Effler PV, Kelly H, Smith DW, Borland ML, Willis GA, Levy A, Keil AD, Richmond PC, et al. Influenza vaccine effectiveness and uptake in children at risk of severe disease. Pediatr Infect Dis J 2016; 35(3):309-15; PMID:26646548; https://doi.org/10.1097/INF.0000000000000999
72. McLean HQ, Thompson MG, Sundaram ME, Kieke BA, Gaglani M, Murthy K, Piedra PA, Zimmerman RK, Nowalk MP, Raviotta JM, et al. Influenza vaccine effectiveness in the United States during 2012–2013: variable protection by age and virus type. J Infect Dis 2015; 211(10):1529-40; PMID:25406334; https://doi.org/10.1093/infdis/jiu647
73. Belongia EA, Kieke BA, Donahue JG, Coleman LA, Irving SA, Meece JK, Vandermause M, Lindstrom S, Gargiullo P, Shay DK. Influenza vaccine effectiveness in Wisconsin during the 2007–08 season: comparison of interim and final results. Vaccine 2011; 29(38):655; https://doi.org/10.1016/j.vaccine.2011.07.002
74. Joshi AY, Iyer VN, St Sauver JL, Jacobson RM, Boyce TG. Effectiveness of inactivated influenza vaccine in children less than 5 years of age over multiple influenza seasons: a case-control study. Vaccine 2009; 27(33):4457-61; PMID:19490957; https://doi.org/10.1016/j.vaccine.2009.05.038
75. Shuler CM, Iwamoto M, Bridges CB, Marin M, Neeman R, Gargiullo P, Yoder TA, Keyserling HL, Terebuh PD. Vaccine effectiveness against medically attended, laboratory-confirmed influenza among children aged 6 to 59 months, 2003–2004. Pediatrics 2007; 119(3):e587-95; PMID:17332179; https://doi.org/10.1542/peds.2006-1878
76. Chiu SS, Feng S, Chan KH, Lo JY, Chan EL, So LY, Cowling BJ, Peiris JS. Hospital-based vaccine effectiveness against influenza B lineages, Hong Kong, 2009–14. Vaccine 2016; 34(19):2164-9; PMID:27013437; https://doi.org/10.1016/j.vaccine.2016.03.032
77. Grijalva CG, Zhu Y, Williams DJ, Self WH, Ampofo K, Pavia AT, Stockmann CR, McCullers J, Arnold SR, Wunderink RG, et al. Association Between Hospitalization With Community-Acquired Laboratory-Confirmed Influenza Pneumonia and Prior Receipt of Influenza Vaccination. JAMA 2015; 314(14):1488-97; PMID:26436611; https://doi.org/10.1001/jama.2015.12160
78. Cowling BJ, Chan KH, Feng S, Chan EL, Lo JY, Peiris JS, Chiu SS. The effectiveness of influenza vaccination in preventing hospitalizations in children in Hong Kong, 2009–2013. Vaccine 2014; 32(41):5278-84; PMID:25092636; https://doi.org/10.1016/j.vaccine.2014.07.084
79. Ferdinands JM, Olsho LE, Agan AA, Bhat N, Sullivan RM, Hall M, Mourani PM, Thompson M, Randolph AG, Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network. Effectiveness of influenza vaccine against life-threatening RT-PCR-confirmed influenza illness in US children, 2010–2012. J Infect Dis 2014; 210(5):674-83; PMID:24676207; https://doi.org/10.1093/infdis/jiu185
80. Gilca R, Deceuninck G, De Serres G, Boulianne N, Sauvageau C, Quach C, Boucher FD, Skowronski DM. Effectiveness of pandemic H1N1 vaccine against influenza-related hospitalization in children. Pediatrics 2011; 128(5):e1084-91; PMID:21987710; https://doi.org/10.1542/peds.2010-3492
81. Griffin MR, Monto AS, Belongia EA, Treanor JJ, Chen Q, Chen J, Talbot HK, Ohmit SE, Coleman LA, Lofthus G, et al. Effectiveness of non-adjuvanted pandemic influenza A vaccines for preventing pandemic influenza acute respiratory illness visits in 4 U.S. communities. PLoS One 2011; 6(8):e23085; PMID:21857999; https://doi.org/10.1371/journal.pone.0023085
82. Chen Q, Griffin MR, Nian H, Zhu Y, Williams JV, Edwards KM, Talbot HK. Influenza vaccine prevents medically attended influenza-associated acute respiratory illness in adults aged ≥ 50 years. J Infect Dis 2015; 211(7):1045-50; PMID:25336724; https://doi.org/10.1093/infdis/jiu578
83. Havers F, Sokolow L, Shay DK, Farley MM, Monroe M, Meek J, Daily Kirley P, Bennett NM, Morin C, Aragon D, et al. Case-Control Study of Vaccine Effectiveness in Preventing Laboratory-Confirmed Influenza Hospitalizations in Older Adults, United States, 2010–2011. Clin Infect Dis 2016; 63(10):1304-11; PMID:27486114; https://doi.org/10.1093/cid/ciw512
84. Puig-Barbera J, Mira-Iglesias A, Tortajada-Girbes M, Lopez-Labrador FX, Belenguer-Varea A, Carballido-Fernandez M, Carbonell-Franco E, Carratala-Munuera C, Limon-Ramirez R, Mollar-Maseres J, et al. Effectiveness of influenza vaccination programme in preventing hospital admissions, Valencia, 2014/15 early results. Euro Surveill 2015; 20(8);pii:21044; https://doi.org/10.2807/1560-7917.ES2015.20.8.21044
85. Castilla J, Martínez-Baz I, Navascués A, Fernandez-Alonso M, Reina G, Guevara M, Chamorro J, Ortega MT, Albéniz E, Pozo F, et al. Vaccine effectiveness in preventing laboratory-confirmed influenza in Navarre, Spain: 2013/14 mid-season analysis. Euro Surveill 2014; 19(6);pii:20700; https://doi.org/10.2807/1560-7917.ES2014.19.6.20700
86. Kwong JC, Campitelli MA, Gubbay JB, Peci A, Winter AL, Olsha R, Turner R, Rosella LC, Crowcroft NS. Vaccine effectiveness against laboratory-confirmed influenza hospitalizations among elderly adults during the 2010–2011 season. Clin Infect Dis 2013; 57(6); PMID:23788243; https://doi.org/10.1093/cid/cit404
87. Van Vuuren A, Rheeder P, Hak E. Effectiveness of influenza vaccination in the elderly in South Africa. Epidemiol Infect 2009; 137(7):994-1002; PMID:18925986; https://doi.org/10.1017/S0950268808001386