Efficacy of influenza vaccine among geriatric inpatients: effect of previous vaccination and antibody induction by single and twice injections

To investigate the effect of previous influenza vaccination and the difference in antibody induction by single and twice injection of influenza vaccine in the elderly, hemagglutination inhibition (HI) antibody titers of the three types of influenza viruses were measured. Influenza vaccination was done for 217 inpatients. For the patients who had influenza vaccination in the year prior to the study, influenza vaccine was administered once to 77 patients and twice to another 70 patients. Influenza vaccine was injected twice to 70 patients who had not received influenza vaccine in the previous years. The influenza vaccine induced an increase in HI titer in almost all patients. The geometric mean of the HI titer and the frequency of patients with HI titers over 128x were similar after vaccination in the groups of patients who were injected twice, irrespective of whether or not influenza vaccination was given in the year prior to the study. The geometric means of the HI titers for influenzas A/H3N2 and B and the frequency of HI titers over 128x for influenza A/H3N2 after vaccination were lower in the patients who received vaccine once than in the patients vaccinated twice. These results suggest that prior vaccination does not diminish antibody response to influenza vaccine significantly in the elderly when influenza vaccine is injected twice. Although single injection is inferior to twice injection in antibody induction with some vaccine virus strains, induction of HI titers over 128x is found in more than 70% of elderly. Single injection of influenza vaccine may be practically effective and useful for protection of influenza infection in the elderly.     

The measurement of influenza vaccine coverage among health care workers

BACKGROUND: Annual influenza vaccination is recommended for health care workers in both the United States and Canada. Estimations of vaccine coverage are commonly used to evaluate these vaccination programs. PURPOSE: We identify, discuss, and illustrate challenges including definitions of health care worker (HCW), selection of indicators, and data sources in the estimation of staff influenza vaccination coverage rates. METHODS: To illustrate the impact of the factors we discuss, we created a database of a simulated pool of HCWs that included varying proportions of permanent, casual, and contract staff under differing scenarios of staff turnover and differing probabilities of individuals being vaccinated. The Excel 97 random number generator (Microsoft) was used to randomly allocate the HCW to different strata under differing staff turnover rates and to designate individuals as being vaccinated. RESULTS: The nature of the staff targeted in the program policy has a large impact on the estimations of vaccine coverage. Different indicators provide data that might be useful for different purposes. The counts in the numerator and denominator of a period prevalence may be useful for estimation of the total workload required of the vaccination program. An incidence density might be useful as an indicator of the efficiency of the program in "capturing" staff for vaccination. The indicator that may be easiest is the point prevalence. CONCLUSION: Program evaluators must think carefully when planning to estimate staff vaccination coverage to avoid invalid comparisons of estimates over time and place. State or province-wide targets for health care worker (HCW) vaccination may be meaningless unless appropriate criteria for the calculation of influenza vaccination rates are developed and specified.     

Peritonitis in geriatric inpatients

Of 212 cases of peritonitis found in a retrospective study of geriatric inpatients, the most common causes were mesenteric infarction, malignancy, intestinal obstruction, perforated peptic ulcer, cholecystitis, diverticulitis and perforation of the urinary bladder. The diagnostic accuracy was 47%. Abdominal pain had been observed in only 55% of the cases, and guarding and/or abdominal rigidity in only 34%. Other findings such as tachycardia and fever were more common, but the specificities of these signs were low.     

High-sensitivity cardiac troponin T in geriatric inpatients

BackgroundHigh-sensitivity cardiac troponin T (hs-cTnT) is detectable in elderly patients without clinical diagnosed cardiovascular disease. Elevated hs-cTnT levels predict increased cardiovascular risks and poor prognosis. The aim of this study was to determine the distribution and associated factors of hs-cTnT in geriatric inpatients without acute coronary syndrome (ACS).MethodsHs-cTnT was measured with a highly sensitive assay in 679 geriatric inpatients without ACS. Patients were further divided into 3 groups according to the tertile of hs-cTnT levels and single and multiple variable analyses were performed to assess the association of hs-cTnT to cardiovascular risk factors, biochemical measurements and echocardiographic abnormalities.ResultsHs-cTnT was detectable (≥3 ng/L) in 98.4% of the subjects and 52.0% of the subjects had hs-cTnT levels ≥14 ng/L, which is at the 99th percentile Upper Reference Limit (URL). The levels of hs-cTnT were independently associated with N-terminal pro-brain natriuretic peptide (NT-proBNP), male gender, older age, estimated glomerular filtration rate (eGFR), left ventricular mass index (LVMI), diabetes mellitus (DM) and left ventricular ejection fraction (LVEF). There were no significant differences in hs-cTnT levels between geriatrics patients with stable coronary artery disease (SCAD) and those without SCAD.ConclusionHs-cTnT elevation caused by non-ischemic acute conditions was very common in geriatric hospitalized patients. Due to increases in baseline hs-cTnT in the elderly, detection of a rise and/or fall in hs-cTnT levels is essential for determining a diagnosis of ACS or AMI in geriatric patients. Further studies are needed to establish age-specific 99th percentile values of hs-cTnT for elderly individuals.     

The efficacy of influenza vaccine for acute exacerbation of chronic obstructive lung disease in elderly patients

OBJECTIVE: Acute exacerbations adversely affect the quality of life and prognosis of patients with chronic obstructive lung disease (COPD). Prevention of future exacerbations is extremely important, especially for elderly patients. In this study, we evaluated the efficacy of influenza vaccine for acute exacerbation of COPD in elderly patients. METHODS: A prospective cohort study was conducted among 289 patients over 65 years of age with COPD (FEV1/FCV<0.70) during the 2001-2002 influenza season. Background data, outpatient visits for wheezing and hospitalizations were compared between the vaccinated group (n = 189) and the unvaccinated group (n = 100). RESULTS: The number of patients who visited hospital for wheezing was 11 of 189 (5.8%) in the vaccinated group and 23 of 100 (23%) in the unvaccinated group (RRR: relative risk reduction 74.7%, 95% CI: confidence interval 0.51-0.87). The number of hospitalizations for pneumonia was 8 of 189 (4.2%) in the vaccinated group and 14 of 100 (14%) in the unvaccinated group (RRR 69.8%, 95% CI: 0.32-0.87). The costs of hospitalization were lower in the vaccinated group with direct savings of 91,525 yen per patient. CONCLUSIONS: For elderly COPD patients, influenza vaccine decreases acute exacerbation due to pneumonia and bronchoconstriction, and also may minimize the costs of hospitalization.     

Medical comorbidity and rehabilitation efficiency in geriatric inpatients

OBJECTIVES: To measure and describe medical comorbidity in geriatric rehabilitation patients and investigate its relationship to rehabilitation efficiency. DESIGN: Prospective, multivariate, within-subject design. SETTING: The Geriatric Rehabilitation inpatient unit of the SCO Health Service in Ottawa, Canada. PARTICIPANTS: One hundred ten patients, with a mean age of 82 years. MEASUREMENTS: The rehabilitation efficiency ratio, based on gains in functional status achieved with rehabilitation treatment, and the length of stay were computed for all patients. Values were regressed on the scores of the Cumulative Illness Rating Scale (CIRS), the Mini-Mental State Examination, and the Geriatric Depression Scale to establish predictive power. RESULTS: The findings suggest that geriatric rehabilitation patients experience considerable medical comorbidity. Sixty percent of patients had impairments across six of the 13 dimensions of the CIRS, whereas 36% of patients had impairments across 11 of the 13 dimensions. In addition, medical comorbidity was negatively related to rehabilitation efficiency. This relationship was significant even after controlling for age, cognitive status, depressive symptoms, and functional independence status at admission. CONCLUSION: Medical comorbidity was a significant predictor of rehabilitation efficiency in geriatric patients. Comorbidity scores >5 were prognostic of poorer rehabilitation outcomes and can serve as an empirical guide in estimating a patient's suitability for rehabilitation. Medical comorbidity predicted both the overall functional change achieved with retabilitation (Functional Independence Measure gains) and the rate at with which those gains were reached (rehabilitation efficiency ratio).     

Immunogenicity of trivalent-inactivated influenza vaccine among children less than 4 years old

We studied the immunogenicity of trivalent-inactivated influenza vaccine. Subjects were 259 children under 4 years old who visited six pediatric clinics to undergo influenza vaccination. Age distribution was 64 aged <1.0, 65 aged 1.0-1.9, 64 aged 2.0-2.9, and 66 aged 3.0-3.9 years, including subjects who had been previously vaccinated within the last three years, 0% (0/64) aged <1.0, 26% (17/65) aged 1.0-1.9, 72% (46/64) aged 2.0-2.9, and 77% (51/66) aged 3.0-3.9 years old. Two doses of vaccine were given subcutaneously four weeks apart. Dosage was 0.l mL for children under 1 year old, while for children aged one year or older, dosage was 0.2mL, based on standard Japanese recommendations. To measure hemagglutination inhibition (HI) antibody titer, triplet sera were obtained before vaccination (S0), 4 weeks after the first vaccination (S1), and 4 weeks after the second vaccination (S2). The geometric mean of HI antibody titer, the response proportion (titer rise > or =4-fold), and the achievement proportion (postvaccination titer > or =1 : 40) were calculated by age group. Analysis of variance was used to estimate the independent effect of age and prevaccination titer on antibody increase. The geometric means of HI antibody titer were lower among the two younger age groups than among the two older age groups, regardless of vaccine strain or when blood samples were collected. The achievement proportion after 2 doses of vaccine in the <1.0, 1.0-1.9, 2.0-2.9, 3.0-3.9 year age groups were 38%, 58%, 89%, and 85% against A (HI) ; 52%, 54%, 81%, and 73% against A (H3) ; and 23%, 49%, 67%, and 71% against B. Regarding the analysis of variance, prevaccination titer consistently indicated strong effects on antibody increase, regardless of vaccine strain or combination of paired sera. After two doses of vaccine (S2/S0), significant effects of age on antibody induction were shown against A (H1) and B (p = 0.000 and 0.002). Thus, the immunogenicity of trivalent-inactivated influenza vaccine was strongly influenced by prevaccination titer and age. Even two doses of vaccine did not induce a protective antibody level in about 50 to 80% of subjects among infants aged <1.0 year, and 40 to 50% among children 1.0-1.9 year old.     

Strategies to increase influenza vaccine uptake among health care workers in Greece

The aim of the current study was to investigate the contribution of various strategies to increase influenza vaccine uptake among health care workers (HCWs) working in hospitals in Greece during the 2005-2006 season. A total of 132 Greek public hospitals participated in the study. The mean HCWs vaccination rate against influenza during 2005-2006 was 16.36% compared with 1.72% during the previous season. Logistic regression analysis showed that the implementation of the following strategies was significantly associated with influenza vaccination rates above the mean vaccination rate: a mobile vaccination team (OR 2.942, 95% CI 1.154-5.382, p-value 0.016) and lectures on influenza and influenza vaccine (OR 2.386, 95% CI 0.999-5.704, p-value 0.036). In conclusion, in Greece influenza vaccination rates among HCWs remain low; however, the implementation of specific strategies was associated with increased vaccine uptakes.     

流感疫苗的研究进展

目前流感疫苗的生产还是以鸡胚苗为主,问题仍然在于候选疫苗株的筛选方面;细胞苗的设计理念与流行病毒匹配,因此其保护效果也强于鸡胚苗,但由于设施不够完善等原因, 目前细胞苗的生产还不能与鸡胚苗相比,因此本文认为应在鸡胚苗的基础上改善季节性流感疫苗疫苗株的筛选。高危人群的界定仍以世界卫生组织(WHO)为主,但在儿童和青少年的接种方面各国有所不同;一般敏感人群也可以进行疫苗接种保护。通用疫苗目前还处于研究阶段,但人们不宜把希望太多寄托在该苗上。