Clinical impact of influenza immunization in patients with liver cirrhosis.

BACKGROUND: Influenza vaccine is considered to reduce influenza-related morbidity and mortality in patients with underlying chronic medical conditions. Yet in liver cirrhosis, influenza vaccines have received little attention in determining the potential benefits. OBJECTIVES: We intended to evaluate the clinical benefits of influenza vaccination and clinical outcomes of influenza in patients with liver cirrhosis. METHODS: We performed a controlled, prospective clinical trial of 311 cirrhotic patients, who were enrolled in October 2004. Among them, 198 patients were vaccinated with a trivalent influenza vaccine and the rest were not vaccinated. Both groups were followed with respect to the occurrence of influenza-like illness (ILI) until May 2005. RESULTS: Overall incidences of ILI (p=0.064) and culture positivity of influenza (p=0.009) were remarkably higher in unvaccinated group compared to the vaccinated group. Most of the cirrhotic patients with influenza had fever (91.6%) and complained of myalgia (83.3%) without respiratory symptoms, which were not typical clinical presentations of influenza. Influenza vaccination also decreased influenza-related complication rates in patients with liver cirrhosis. CONCLUSION: Influenza vaccination should be recommended to all cirrhotic patients. High suspicion is required for early diagnosis and antiviral treatment, allowing for the frequent hepatic decompensation among cirrhotic patients.

Debate on annual influenza vaccination in healthcare workers for the same subtype under the vaccine shortage.

BACKGROUND: Influenza vaccination is the primary method for preventing influenza and its severe complications. Healthcare workers (HCWs) are one of the priority groups for the influenza vaccination. OBJECTIVES: To determine whether healthy HCWs, who were vaccinated with the same subtype for the two previous years, could be given less priority for influenza immunization under the vaccine shortage. STUDY DESIGN: We measured hemagglutination-inhibition antibody titers from sequential serum samples in 50 pre-immune subjects and 50 age-matched vaccine-naive subjects: immediately prior to the administration of the vaccine, 4-6 weeks, and 6 months after the vaccination. RESULTS: Prevaccination titers were maintained above protective level and high protection rates were observed for all three strains in pre-immune subjects: A/H1N1, A/H3N2, and B strains. As for the sequential changes, the protection rates for all three strains still remained above 70% until 6 months following the vaccination. CONCLUSION: Skipping influenza vaccination for a year could be considered in healthy pre-immune HCWs under the epidemic of the same subtype as two previous years.

Active influenza immunization in hemodialysis patients: comparison between single-dose and booster vaccination.

BACKGROUND/AIMS: Hemodialysis (HD) patients are recommended to be immunized against influenza annually, but the immune response after vaccination is known to be weakened in these patients. We intended to compare the efficacy of influenza vaccines in HD patients with that in healthy people, and we also evaluated the additive effect of a booster vaccination in HD patients. METHODS: During the 2003-2004 influenza season, 100 patients on HD and 50 age-matched healthy controls were recruited from the Korea University Guro Hospital. The HD patients were divided into two groups: single-dose group (50 patients) and booster group (50 patients). Eight weeks following the influenza vaccination, the serum antibody responses were compared. RESULTS: Although the antibody response of the HD patients was impaired in comparison with that of healthy controls, more than 90% of the HD patients showed protective antibody levels. Booster vaccination did not significantly increase the immune response in HD patients. CONCLUSIONS: Influenza vaccination in HD patients should be encouraged, but the immune response was comparatively impaired in subpopulations, including patients with a long-term HD history (>2.5 years), with a higher urea reduction rate, or with underlying diabetes. There was no effect of a booster vaccine dose on the antibody titers.