Reduced incidence of pneumonia in influenza-vaccinated solid organ transplant recipients with influenza disease

Abstract

Whether influenza vaccination influences the severity of illness in cases of clinical failure in solid organ transplant (SOT) recipients receiving influenza vaccine has not been extensively studied. Our goal was to evaluate the frequency of influenza vaccination among SOT recipients with influenza disease and its impact on the illness severity during the 2010-2011 season. Adult SOT recipients with confirmed influenza infection were included from December 2010 to April 2011. Follow-up data were recorded and antibody titres were determined using a microneutralization assay. Sixty-four SOT recipients were included in the study, ten (15.6%) with severe disease, requiring admission to intensive care units, of whom four (6.3%) died. In all, 34 (53.1%) received the 2010-2011 seasonal influenza vaccine and 32 (50.0%) received the 2009-H1N1 pandemic vaccine, and none had detectable antibodies against influenza at the time of diagnosis of influenza infection. Twenty-three (67.6%) of the patients that received the vaccine required hospital admission and presented less dyspnoea (10, 29.4% versus 14 (50.0%), p 0.09) and pneumonia (8, 23.8% versus 15, 50.0%, p 0.03, relative risk 0.3, 95% CI 0.1-0.9) than unvaccinated patients, with relative risk reductions of 60% and 70%, respectively. Although influenza vaccination confers protection on SOT recipients against developing influenza pneumonia, the rate of clinical failure is still high. New strategies to improve influenza immunization are needed for this group of patients.

Clinical features and outcomes of influenza infections in lung transplant recipients: a single‐season cohort study

“…Influenza‐related mortality in SOT recipients has been reported to range from 4% to 40% . We had no influenza‐related deaths, similar to 2 other studies managing most LTRs as outpatients .…”

“…Immunosuppression, drug‐resistant influenza strains, pediatric age, and delayed treatment initiation have previously been associated with PVS . Most recent publications on influenza infections in SOT recipients report hospitalization rates of 63–100% . In our cohort, most patients were managed as outpatients; this is similar to 2 other smaller studies in LTRs .…”

Determinants of influenza vaccination among solid organ transplant recipients attending Sicilian reference center

“…Other studies have found health benefits of anti-influenza vaccine in high-risk categories. 6,22 Even though further research is needed to evaluate the overall risks and benefits of anti-influenza-vaccine in SOT recipients.…”

The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation

“…Despite potential lower immunogenicity of influenza vaccine in SOT recipients due to immunosuppressive drugs, in a retrospective cohort study including >50 000 kidney transplant recipients, influenza vaccination was associated with a lower risk of subsequent allograft loss and death during the first year after transplantation (142). Moreover, a lower incidence of bacterial pneumonia was observed in vaccinated SOT recipients (143), so the use of the annual inactivated influenza vaccine is highly recommended in all transplant recipients.…”