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Evaluation of infection in the older adult

Lona Mody, MD
Section Editor
Kenneth E Schmader, MD
Deputy Editor
H Nancy Sokol, MD


Infection is the primary cause of death in one-third of individuals aged 65 years and older and is a contributor to death for many others [1]. Infection also has a marked impact on morbidity in older adults, exacerbating underlying illnesses and initiating functional decline.

Multiple biologic, cultural, and societal factors account for the increased susceptibility of older adults to infection and their poorer outcomes when infected. These factors also alter the presentation of infectious syndromes in older adults and may necessitate treatment modifications.

The aspects of infectious diseases unique to the older adult will be reviewed here. When available, recommendations for diagnostic evaluation and therapy for the older adult are provided. Multiple topics throughout UpToDate present detailed discussions of pathologic, diagnostic, therapeutic, and preventive aspects related to specific infections.


Fundamental alterations in quantitative and qualitative immune response occur with aging, a process that has been called immune senescence. (See "Immune function in older adults".)

Multiple age-related changes contribute to decreased protection from infection in older adults. These changes include:


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  1. Mouton CP, Bazaldua OV, Pierce B, Espino DV. Common infections in older adults. Am Fam Physician 2001; 63:257.
  2. Gomez CR, Boehmer ED, Kovacs EJ. The aging innate immune system. Curr Opin Immunol 2005; 17:457.
  3. Castle SC, Uyemura K, Fulop T, Makinodan T. Host resistance and immune responses in advanced age. Clin Geriatr Med 2007; 23:463.
  4. Weiskopf D, Weinberger B, Grubeck-Loebenstein B. The aging of the immune system. Transpl Int 2009; 22:1041.
  5. Panda A, Qian F, Mohanty S, et al. Age-associated decrease in TLR function in primary human dendritic cells predicts influenza vaccine response. J Immunol 2010; 184:2518.
  6. Goronzy JJ, Fulbright JW, Crowson CS, et al. Value of immunological markers in predicting responsiveness to influenza vaccination in elderly individuals. J Virol 2001; 75:12182.
  7. Lefebvre JS, Haynes L. Aging of the CD4 T Cell Compartment. Open Longev Sci 2012; 6:83.
  8. Scholz JL, Diaz A, Riley RL, et al. A comparative review of aging and B cell function in mice and humans. Curr Opin Immunol 2013; 25:504.
  9. Listì F, Candore G, Modica MA, et al. A study of serum immunoglobulin levels in elderly persons that provides new insights into B cell immunosenescence. Ann N Y Acad Sci 2006; 1089:487.
  10. Pfister G, Weiskopf D, Lazuardi L, et al. Naive T cells in the elderly: are they still there? Ann N Y Acad Sci 2006; 1067:152.
  11. Bradley SF. Issues in the management of resistant bacteria in long-term-care facilities. Infect Control Hosp Epidemiol 1999; 20:362.
  12. Kupronis BA, Richards CL, Whitney CG, Active Bacterial Core Surveillance Team. Invasive pneumococcal disease in older adults residing in long-term care facilities and in the community. J Am Geriatr Soc 2003; 51:1520.
  13. O'Fallon E, Schreiber R, Kandel R, D'Agata EM. Multidrug-resistant gram-negative bacteria at a long-term care facility: assessment of residents, healthcare workers, and inanimate surfaces. Infect Control Hosp Epidemiol 2009; 30:1172.
  14. Wang L, Lansing B, Symons K, et al. Infection rate and colonization with antibiotic-resistant organisms in skilled nursing facility residents with indwelling devices. Eur J Clin Microbiol Infect Dis 2012; 31:1797.
  15. Flannery EL, Wang L, Zöllner S, et al. Wounds, functional disability, and indwelling devices are associated with cocolonization by methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in southeast Michigan. Clin Infect Dis 2011; 53:1215.
  16. Loeb M, Simor AE, Landry L, et al. Antibiotic use in Ontario facilities that provide chronic care. J Gen Intern Med 2001; 16:376.
  17. Daneman N, Bronskill SE, Gruneir A, et al. Variability in Antibiotic Use Across Nursing Homes and the Risk of Antibiotic-Related Adverse Outcomes for Individual Residents. JAMA Intern Med 2015; 175:1331.
  18. Peron EP, Hirsch AA, Jury LA, et al. Another setting for stewardship: high rate of unnecessary antimicrobial use in a veterans affairs long-term care facility. J Am Geriatr Soc 2013; 61:289.
  19. Wunderlich CA. On the Temperature in Diseases: A Manual of Medical Thermometry, William Wood and Co, New York 1871. p.46.
  20. Osler W. The Principles and Practice of Medicine, D. Appleton, New York 1982. p.517.
  21. Henschke PJ. Infections in the elderly. Med J Aust 1993; 158:830.
  22. Musgrave T, Verghese A. Clinical features of pneumonia in the elderly. Semin Respir Infect 1990; 5:269.
  23. Bender BS, Scarpace PJ. Fever in the Elderly. In: Fever: Basic Mechanisms and Management, MacKowiak PA (Ed), Lippincott-Raven, Philadelphia 1997. p.363.
  24. Gomolin IH, Aung MM, Wolf-Klein G, Auerbach C. Older is colder: temperature range and variation in older people. J Am Geriatr Soc 2005; 53:2170.
  25. Norman DC. Fever in the elderly. Clin Infect Dis 2000; 31:148.
  26. Castle SC, Yeh M, Toledo SD, et al. Lowering the fever criterea improves detection of infections in nursing home residents. Aging Immunol Infect Dis 1993; 4:67.
  27. Eke-Usim AC, Rogers MA, Gibson KE, et al. Constitutional Symptoms Trigger Diagnostic Testing Before Antibiotic Prescribing in High-Risk Nursing Home Residents. J Am Geriatr Soc 2016; 64:1975.
  28. van Duin D. Diagnostic challenges and opportunities in older adults with infectious diseases. Clin Infect Dis 2012; 54:973.
  29. High KP, Bradley SF, Gravenstein S, et al. Clinical practice guideline for the evaluation of fever and infection in older adult residents of long-term care facilities: 2008 update by the Infectious Diseases Society of America. Clin Infect Dis 2009; 48:149.
  30. Herring AR, Williamson JC. Principles of antimicrobial use in older adults. Clin Geriatr Med 2007; 23:481.
  31. Coresh J, Astor BC, Greene T, et al. Prevalence of chronic kidney disease and decreased kidney function in the adult US population: Third National Health and Nutrition Examination Survey. Am J Kidney Dis 2003; 41:1.
  32. Drusano GL, Preston SL, Fowler C, et al. Relationship between fluoroquinolone area under the curve: minimum inhibitory concentration ratio and the probability of eradication of the infecting pathogen, in patients with nosocomial pneumonia. J Infect Dis 2004; 189:1590.
  33. Kollef MH. The importance of appropriate initial antibiotic therapy for hospital-acquired infections. Am J Med 2003; 115:582.
  34. Fridkin S, Baggs J, Fagan R, et al. Vital signs: improving antibiotic use among hospitalized patients. MMWR Morb Mortal Wkly Rep 2014; 63:194.
  35. Meehan TP, Fine MJ, Krumholz HM, et al. Quality of care, process, and outcomes in elderly patients with pneumonia. JAMA 1997; 278:2080.
  36. Gavazzi G, Mallaret MR, Couturier P, et al. Bloodstream infection: differences between young-old, old, and old-old patients. J Am Geriatr Soc 2002; 50:1667.
  37. Pien BC, Sundaram P, Raoof N, et al. The clinical and prognostic importance of positive blood cultures in adults. Am J Med 2010; 123:819.
  38. Kaye KS, Marchaim D, Chen TY, et al. Predictors of nosocomial bloodstream infections in older adults. J Am Geriatr Soc 2011; 59:622.
  39. Kaye KS, Marchaim D, Chen TY, et al. Effect of nosocomial bloodstream infections on mortality, length of stay, and hospital costs in older adults. J Am Geriatr Soc 2014; 62:306.
  40. Knockaert DC, Vanneste LJ, Bobbaers HJ. Fever of unknown origin in elderly patients. J Am Geriatr Soc 1993; 41:1187.
  41. Esposito AL, Gleckman RA. Fever of unknown origin in the elderly. J Am Geriatr Soc 1978; 26:498.
  42. Tal S, Guller V, Gurevich A, Levi S. Fever of unknown origin in the elderly. J Intern Med 2002; 252:295.
  43. Mourad O, Palda V, Detsky AS. A comprehensive evidence-based approach to fever of unknown origin. Arch Intern Med 2003; 163:545.
  44. Tal S, Guller V, Gurevich A. Fever of unknown origin in older adults. Clin Geriatr Med 2007; 23:649.
  45. Ely EW, Angus DC, Williams MD, et al. Drotrecogin alfa (activated) treatment of older patients with severe sepsis. Clin Infect Dis 2003; 37:187.
  46. Barrier J, Schneebeli S, Peltier P. Les Fievres prolongees inexpliquees chez les personnes, agees. Concours Med 1982; 104:4679.
  47. Dhawan VK. Infective endocarditis in elderly patients. Clin Infect Dis 2002; 34:806.
  48. Hoen B, Alla F, Selton-Suty C, et al. Changing profile of infective endocarditis: results of a 1-year survey in France. JAMA 2002; 288:75.
  49. Durante-Mangoni E, Bradley S, Selton-Suty C, et al. Current features of infective endocarditis in elderly patients: results of the International Collaboration on Endocarditis Prospective Cohort Study. Arch Intern Med 2008; 168:2095.
  50. Stall R, Catania J. AIDS risk behaviors among late middle-aged and elderly Americans. The National AIDS Behavioral Surveys. Arch Intern Med 1994; 154:57.
  51. Murphree DD, DeHaven MJ. Does grandma need condoms? Condom use among women in a family practice setting. Arch Fam Med 1995; 4:233.
  52. Amin I. Social Capital and Sexual Risk-Taking Behaviors Among Older Adults in the United States. J Appl Gerontol 2016; 35:982.
  53. Lindau ST, Schumm LP, Laumann EO, et al. A study of sexuality and health among older adults in the United States. N Engl J Med 2007; 357:762.
  54. Perez JL, Moore RD. Greater effect of highly active antiretroviral therapy on survival in people aged > or =50 years compared with younger people in an urban observational cohort. Clin Infect Dis 2003; 36:212.
  55. Wellons MF, Sanders L, Edwards LJ, et al. HIV infection: treatment outcomes in older and younger adults. J Am Geriatr Soc 2002; 50:603.
  56. Shah SS, McGowan JP, Smith C, et al. Comorbid conditions, treatment, and health maintenance in older persons with human immunodeficiency virus infection in New York City. Clin Infect Dis 2002; 35:1238.
  57. Hasse B, Ledergerber B, Furrer H, et al. Morbidity and aging in HIV-infected persons: the Swiss HIV cohort study. Clin Infect Dis 2011; 53:1130.
  58. Guaraldi G, Orlando G, Zona S, et al. Premature age-related comorbidities among HIV-infected persons compared with the general population. Clin Infect Dis 2011; 53:1120.
  59. Justice AC, McGinnis KA, Skanderson M, et al. Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers. HIV Med 2010; 11:143.
  60. Desquilbet L, Jacobson LP, Fried LP, et al. A frailty-related phenotype before HAART initiation as an independent risk factor for AIDS or death after HAART among HIV-infected men. J Gerontol A Biol Sci Med Sci 2011; 66:1030.
  61. Shah K, Hilton TN, Myers L, et al. A new frailty syndrome: central obesity and frailty in older adults with the human immunodeficiency virus. J Am Geriatr Soc 2012; 60:545.
  62. Kim DJ, Westfall AO, Chamot E, et al. Multimorbidity patterns in HIV-infected patients: the role of obesity in chronic disease clustering. J Acquir Immune Defic Syndr 2012; 61:600.
  63. Erlandson KM, Allshouse AA, Jankowski CM, et al. Risk factors for falls in HIV-infected persons. J Acquir Immune Defic Syndr 2012; 61:484.
  64. Kaplan V, Angus DC, Griffin MF, et al. Hospitalized community-acquired pneumonia in the elderly: age- and sex-related patterns of care and outcome in the United States. Am J Respir Crit Care Med 2002; 165:766.
  65. Jackson ML, Neuzil KM, Thompson WW, et al. The burden of community-acquired pneumonia in seniors: results of a population-based study. Clin Infect Dis 2004; 39:1642.
  66. Fry AM, Shay DK, Holman RC, et al. Trends in hospitalizations for pneumonia among persons aged 65 years or older in the United States, 1988-2002. JAMA 2005; 294:2712.
  67. Donowitz GR, Cox HL. Bacterial community-acquired pneumonia in older patients. Clin Geriatr Med 2007; 23:515.
  68. Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med 1997; 336:243.
  69. Man SY, Lee N, Ip M, et al. Prospective comparison of three predictive rules for assessing severity of community-acquired pneumonia in Hong Kong. Thorax 2007; 62:348.
  70. Conte HA, Chen YT, Mehal W, et al. A prognostic rule for elderly patients admitted with community-acquired pneumonia. Am J Med 1999; 106:20.
  71. Ruhnke GW, Coca-Perraillon M, Kitch BT, Cutler DM. Marked reduction in 30-day mortality among elderly patients with community-acquired pneumonia. Am J Med 2011; 124:171.
  72. El-Solh AA, Sikka P, Ramadan F, Davies J. Etiology of severe pneumonia in the very elderly. Am J Respir Crit Care Med 2001; 163:645.
  73. Mandell LA, Bartlett JG, Dowell SF, et al. Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults. Clin Infect Dis 2003; 37:1405.
  74. Falsey AR, Erdman D, Anderson LJ, Walsh EE. Human metapneumovirus infections in young and elderly adults. J Infect Dis 2003; 187:785.
  75. Ewig S, Torres A. Is Chlamydia pneumoniae an important pathogen in patients with community-acquired pneumonia? Eur Respir J 2003; 21:741.
  76. Vila-Córcoles A, Ochoa-Gondar O, Hospital I, et al. Protective effects of the 23-valent pneumococcal polysaccharide vaccine in the elderly population: the EVAN-65 study. Clin Infect Dis 2006; 43:860.
  77. Jackson LA, Neuzil KM, Yu O, et al. Effectiveness of pneumococcal polysaccharide vaccine in older adults. N Engl J Med 2003; 348:1747.
  78. Loeb MB, Becker M, Eady A, Walker-Dilks C. Interventions to prevent aspiration pneumonia in older adults: a systematic review. J Am Geriatr Soc 2003; 51:1018.
  79. Logemann JA, Gensler G, Robbins J, et al. A randomized study of three interventions for aspiration of thin liquids in patients with dementia or Parkinson's disease. J Speech Lang Hear Res 2008; 51:173.
  80. Robbins J, Gensler G, Hind J, et al. Comparison of 2 interventions for liquid aspiration on pneumonia incidence: a randomized trial. Ann Intern Med 2008; 148:509.
  81. Juthani-Mehta M, Van Ness PH, McGloin J, et al. A cluster-randomized controlled trial of a multicomponent intervention protocol for pneumonia prevention among nursing home elders. Clin Infect Dis 2015; 60:849.
  82. Juthani-Mehta M, De Rekeneire N, Allore H, et al. Modifiable risk factors for pneumonia requiring hospitalization of community-dwelling older adults: the Health, Aging, and Body Composition Study. J Am Geriatr Soc 2013; 61:1111.
  83. Berdal JE, Skråmm I, Mowinckel P, et al. Use of rifampicin and ciprofloxacin combination therapy after surgical debridement in the treatment of early manifestation prosthetic joint infections. Clin Microbiol Infect 2005; 11:843.
  84. Barberán J, Aguilar L, Carroquino G, et al. Conservative treatment of staphylococcal prosthetic joint infections in elderly patients. Am J Med 2006; 119:993.e7.
  85. Senneville E, Joulie D, Legout L, et al. Outcome and predictors of treatment failure in total hip/knee prosthetic joint infections due to Staphylococcus aureus. Clin Infect Dis 2011; 53:334.
  86. High KP, Bradley S, Loeb M, et al. A new paradigm for clinical investigation of infectious syndromes in older adults: assessment of functional status as a risk factor and outcome measure. Clin Infect Dis 2005; 40:114.
  87. Fisman DN, Reilly DT, Karchmer AW, Goldie SJ. Clinical effectiveness and cost-effectiveness of 2 management strategies for infected total hip arthroplasty in the elderly. Clin Infect Dis 2001; 32:419.
  88. Betsch BY, Eggli S, Siebenrock KA, et al. Treatment of joint prosthesis infection in accordance with current recommendations improves outcome. Clin Infect Dis 2008; 46:1221.
  89. Toulson C, Walcott-Sapp S, Hur J, et al. Treatment of infected total hip arthroplasty with a 2-stage reimplantation protocol: update on "our institution's" experience from 1989 to 2003. J Arthroplasty 2009; 24:1051.
  90. Lieberman JR, Callaway GH, Salvati EA, et al. Treatment of the infected total hip arthroplasty with a two-stage reimplantation protocol. Clin Orthop Relat Res 1994; :205.
  91. Foxman B, Brown P. Epidemiology of urinary tract infections: transmission and risk factors, incidence, and costs. Infect Dis Clin North Am 2003; 17:227.
  92. Juthani-Mehta M. Asymptomatic bacteriuria and urinary tract infection in older adults. Clin Geriatr Med 2007; 23:585.
  93. Nicolle LE, Bradley S, Colgan R, et al. Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis 2005; 40:643.
  94. Trautner BW, Grigoryan L, Petersen NJ, et al. Effectiveness of an Antimicrobial Stewardship Approach for Urinary Catheter-Associated Asymptomatic Bacteriuria. JAMA Intern Med 2015; 175:1120.
  95. Nace DA, Drinka PJ, Crnich CJ. Clinical uncertainties in the approach to long term care residents with possible urinary tract infection. J Am Med Dir Assoc 2014; 15:133.
  96. Mody L, Juthani-Mehta M. Urinary tract infections in older women: a clinical review. JAMA 2014; 311:844.
  97. Wilson ML, Gaido L. Laboratory diagnosis of urinary tract infections in adult patients. Clin Infect Dis 2004; 38:1150.
  98. Knottnerus BJ, Geerlings SE, Moll van Charante EP, ter Riet G. Women with symptoms of uncomplicated urinary tract infection are often willing to delay antibiotic treatment: a prospective cohort study. BMC Fam Pract 2013; 14:71.
  99. Loeb M, Bentley DW, Bradley S, et al. Development of minimum criteria for the initiation of antibiotics in residents of long-term-care facilities: results of a consensus conference. Infect Control Hosp Epidemiol 2001; 22:120.
  100. Lutters M, Vogt-Ferrier NB. Antibiotic duration for treating uncomplicated, symptomatic lower urinary tract infections in elderly women. Cochrane Database Syst Rev 2008; :CD001535.
  101. Lesourd BM, Mazari L. Immune responses during recovery from protein-energy malnutrition. Clin Nutr 1997; 16 Suppl 1:37.
  102. Lesourd B. Protein undernutrition as the major cause of decreased immune function in the elderly: clinical and functional implications. Nutr Rev 1995; 53:S86.
  103. Lesourd BM. Nutrition and immunity in the elderly: modification of immune responses with nutritional treatments. Am J Clin Nutr 1997; 66:478S.
  104. Talbott MC, Miller LT, Kerkvliet NI. Pyridoxine supplementation: effect on lymphocyte responses in elderly persons. Am J Clin Nutr 1987; 46:659.
  105. Prasad AS, Fitzgerald JT, Hess JW, et al. Zinc deficiency in elderly patients. Nutrition 1993; 9:218.
  106. Lesourd BM, Mazari L, Ferry M. The role of nutrition in immunity in the aged. Nutr Rev 1998; 56:S113.
  107. Barnett JB, Hamer DH, Meydani SN. Low zinc status: a new risk factor for pneumonia in the elderly? Nutr Rev 2010; 68:30.
  108. High KP. Nutritional strategies to boost immunity and prevent infection in elderly individuals. Clin Infect Dis 2001; 33:1892.
  109. Forster SE, Powers HJ, Foulds GA, et al. Improvement in nutritional status reduces the clinical impact of infections in older adults. J Am Geriatr Soc 2012; 60:1645.
  110. Barringer TA, Kirk JK, Santaniello AC, et al. Effect of a multivitamin and mineral supplement on infection and quality of life. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2003; 138:365.
  111. Avenell A, Campbell MK, Cook JA, et al. Effect of multivitamin and multimineral supplements on morbidity from infections in older people (MAVIS trial): pragmatic, randomised, double blind, placebo controlled trial. BMJ 2005; 331:324.
  112. Wilson MM, Purushothaman R, Morley JE. Effect of liquid dietary supplements on energy intake in the elderly. Am J Clin Nutr 2002; 75:944.
  113. Stamler J, Elliott P, Kesteloot H, et al. Inverse relation of dietary protein markers with blood pressure. Findings for 10,020 men and women in the INTERSALT Study. INTERSALT Cooperative Research Group. INTERnational study of SALT and blood pressure. Circulation 1996; 94:1629.
  114. Hu FB, Stampfer MJ, Manson JE, et al. Dietary protein and risk of ischemic heart disease in women. Am J Clin Nutr 1999; 70:221.
  115. Vellas BJ, Hunt WC, Romero LJ, et al. Changes in nutritional status and patterns of morbidity among free-living elderly persons: a 10-year longitudinal study. Nutrition 1997; 13:515.
  116. Bos C, Benamouzig R, Bruhat A, et al. Nutritional status after short-term dietary supplementation in hospitalized malnourished geriatric patients. Clin Nutr 2001; 20:225.
  117. Tkatch L, Rapin CH, Rizzoli R, et al. Benefits of oral protein supplementation in elderly patients with fracture of the proximal femur. J Am Coll Nutr 1992; 11:519.
  118. Wolfe RR, Miller SL, Miller KB. Optimal protein intake in the elderly. Clin Nutr 2008; 27:675.
  119. Brenner BM, Lawler EV, Mackenzie HS. The hyperfiltration theory: a paradigm shift in nephrology. Kidney Int 1996; 49:1774.
  120. Roughead ZK. Is the interaction between dietary protein and calcium destructive or constructive for bone? J Nutr 2003; 133:866S.
  121. Heaney RP. Protein intake and the calcium economy. J Am Diet Assoc 1993; 93:1259.
  122. Tsui JK, Ross S, Poulin K, et al. The effect of dietary protein on the efficacy of L-dopa: a double-blind study. Neurology 1989; 39:549.
  123. Pincus JH, Barry K. Influence of dietary protein on motor fluctuations in Parkinson's disease. Arch Neurol 1987; 44:270.
  124. Gergen PJ, McQuillan GM, Kiely M, et al. A population-based serologic survey of immunity to tetanus in the United States. N Engl J Med 1995; 332:761.
  125. Centers for Disease Control and Prevention (CDC). FDA approval of expanded age indication for a tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine. MMWR Morb Mortal Wkly Rep 2011; 60:1279.
  126. Moro PL, Yue X, Lewis P, et al. Adverse events after tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine administered to adults 65 years of age and older reported to the Vaccine Adverse Event Reporting System (VAERS), 2005-2010. Vaccine 2011; 29:9404.
  127. Tomczyk S, Bennett NM, Stoecker C, et al. Use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine among adults aged ≥65 years: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep 2014; 63:822.
  128. Aspirin for the Prevention of Cardiovascular Disease: Preventive Medication. USPSTF. Release Date: March 2009. http://www.uspreventiveservicestaskforce.org/Page/Topic/recommendation-summary/aspirin-for-the-prevention-of-cardiovascular-disease-preventive-medication (Accessed on October 06, 2014).
  129. Jackson LA, Benson P, Sneller VP, et al. Safety of revaccination with pneumococcal polysaccharide vaccine. JAMA 1999; 281:243.
  130. Whitney CG, Farley MM, Hadler J, et al. Decline in invasive pneumococcal disease after the introduction of protein-polysaccharide conjugate vaccine. N Engl J Med 2003; 348:1737.
  131. Bridges CB, Harper SA, Fukuda K, et al. Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2003; 52:1.
  132. Centers for Disease Control and Prevention (CDC). Licensure of a high-dose inactivated influenza vaccine for persons aged >or=65 years (Fluzone High-Dose) and guidance for use - United States, 2010. MMWR Morb Mortal Wkly Rep 2010; 59:485.
  133. http://www.cdc.gov/vaccines/acip/meetings/downloads/slides-oct-2013/04-Fluzone-Greenberg.pdf (Accessed on May 21, 2014).
  134. Rivetti D, Jefferson T, Thomas R, et al. Vaccines for preventing influenza in the elderly. Cochrane Database Syst Rev 2006; :CD004876.
  135. Nelson JC, Jackson ML, Weiss NS, Jackson LA. New strategies are needed to improve the accuracy of influenza vaccine effectiveness estimates among seniors. J Clin Epidemiol 2009; 62:687.
  136. Diggory P, Fernandez C, Humphrey A, et al. Comparison of elderly people's technique in using two dry powder inhalers to deliver zanamivir: randomised controlled trial. BMJ 2001; 322:577.
  137. Kaiser L, Wat C, Mills T, et al. Impact of oseltamivir treatment on influenza-related lower respiratory tract complications and hospitalizations. Arch Intern Med 2003; 163:1667.
  138. Schmader K. Herpes zoster in older adults. Clin Infect Dis 2001; 32:1481.
  139. Oxman MN, Levin MJ, Johnson GR, et al. A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. N Engl J Med 2005; 352:2271.
  140. Atkinson WL, Pickering LK, Schwartz B, et al. General recommendations on immunization. Recommendations of the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Family Physicians (AAFP). MMWR Recomm Rep 2002; 51:1.
  141. Tseng HF, Smith N, Sy LS, Jacobsen SJ. Evaluation of the incidence of herpes zoster after concomitant administration of zoster vaccine and polysaccharide pneumococcal vaccine. Vaccine 2011; 29:3628.
  142. Leder K, Weller PF, Wilson ME. Travel vaccines and elderly persons: review of vaccines available in the United States. Clin Infect Dis 2001; 33:1553.
  143. Martin M, Weld LH, Tsai TF, et al. Advanced age a risk factor for illness temporally associated with yellow fever vaccination. Emerg Infect Dis 2001; 7:945.