The Impact of Vaccination on Influenza-Related Respiratory Failure and Mortality in Hospitalized Elderly Patients Over the 2013-2014 Season

Abstract

Background : Seasonal Influenza (“the flu”) is a respiratory illness caused by influenza viruses. Yearly influenza vaccination is considered to be protective against illness and/or severity of illness and is recommended by CDC for all individuals > 6 months of age. However, the effectiveness of influenza vaccine in older individuals has come under question.Objectives : To describe the clinical characteristics and treatment outcomes of patients admitted to an academic tertiary care Veterans Administration hospital with influenza during the 2013-2014 influenza season and determine the impact, if any, of prior influenza vaccination upon patient outcomes.Methods : Medical electronic records were searched for all patients admitted to the Little Rock Veterans Administration Hospital with proven influenza during the 2013-2014 influenza season. Cohorts of vaccinated and non-vaccinated patients were then compared to determine the impact of prior influenza vaccination upon respiratory-failure and mortality.Results : Seventy patients met selection criteria. Mean age was 66 years. Sixty-four (91%) patients had at least one underlying co-morbid condition; these conditions included COPD, congestive heart failure, diabetes, and cancer. 60/70 (85%) tested positive for Influenza A, and 43 tested positive for H1N1. Oseltamivir was initiated in 55 (78%) patients. Forty-four percent of the patients had been vaccinated. When separated by vaccination status, those who had been vaccinated had higher rates of ICU admission, need for mechanical or non-invasive ventilation, and mortality. All but mortality reached statistical significance.Conclusion : The data suggest that there was no protective effect from prior vaccination in preventing hospital admission, respiratory failure, and mortality in this population of older men admitted to the hospital with influenza.

Influenza Vaccination Modifies Disease Severity Among Community-dwelling Adults Hospitalized With Influenza

“…In addition, 2 smaller studies assessed 2013–14 influenza vaccination in adults and its effects on disease severity. One of them [31] reported no effect of influenza vaccination on in-hospital mortality or respiratory failure among older adults hospitalized with influenza. In contrast, the other study reported lower influenza vaccination rates among those who presented with more severe respiratory illness, including need for ICU admission and positive pressure ventilation [32].…”

Vaccine- and natural infection-induced mechanisms that could modulate vaccine safety

“…a virus or bacterium) is encountered.) [ [105] , [106] , [107] , [108] ]; Prior Influenza Infection/Vaccination (effects of prior influenza infection/vaccination on severity of future disease symptoms) [ [109] , [110] , [111] , [112] , [113] , [114] , [115] , [116] ]; Timing between Viral Exposures (elapsed time between viral exposures) [ [117] , [118] , [119] , [120] ]; Vaccine-Associated Enhanced Respiratory Disease (where vaccination enhances respiratory disease) [ [121] , [122] , [123] ]; Chronic Immune Activation (continuous innate immune responses) [ [124] , [125] , [126] ]. …”

“…Prior Influenza Infection/Vaccination (effects of prior influenza infection/vaccination on severity of future disease symptoms) [ [109] , [110] , [111] , [112] , [113] , [114] , [115] , [116] ];…”

Effectiveness of Influenza Vaccination in Hospitalized Cases in Catalonia During the 2017-2018 Season

“…Yet some subsets of population are at higher risk for more severe disease which may require hospitalization and/or intensive care unit admission due to complications such as pneumonia or acute respiratory distress. It is well known that the elderly (≥65 years of age) have the highest risk of increased morbidity including respiratory failure, and mortality; It is estimated that over 60% of all seasonal-influenza-related hospitalizations and 90% of seasonal-influenza-related deaths each year occur in the elderly [2,[3][4][5][6][7] in Europe [9], suggest that vaccination offered only slight protection for severe outcome due to this fact and because there was a high proportion of elderly hospitalizations (79.1%) and that older age is associated with a lower ICU admission [10].Data on the inverse relation between age and ICU admission has also been pointed out by other authors who found higher rate of ICU admission among SHCIC at 15-64 y [11][12][13][14].…”