Humoral and Cell-Mediated Immunity to Pandemic H1N1 Influenza in a Canadian Cohort One Year Post-Pandemic: Implications for Vaccination

We evaluated a cohort of Canadian donors for T cell and antibody responses against influenza A/California/7/2009 (pH1N1) at 8-10 months after the 2nd pandemic wave by flow cytometry and microneutralization assays. Memory CD8 T cell responses to pH1N1 were detectable in 58% (61/105) of donors. These responses were largely due to cross-reactive CD8 T cell epitopes as, for those donors tested, similar recall responses were obtained to A/California 2009 and A/PR8 1934 H1N1 Hviruses. Longitudinal analysis of a single infected individual showed only a small and transient increase in neutralizing antibody levels, but a robust CD8 T cell response that rose rapidly post symptom onset, peaking at 3 weeks, followed by a gradual decline to the baseline levels seen in a seroprevalence cohort post-pandemic. The magnitude of the influenza-specific CD8 T cell memory response at one year post-pandemic was similar in cases and controls as well as in vaccinated and unvaccinated donors, suggesting that any T cell boosting from infection was transient. Pandemic H1-specific antibodies were only detectable in approximately half of vaccinated donors. However, those who were vaccinated within a few months following infection had the highest persisting antibody titers, suggesting that vaccination shortly after influenza infection can boost or sustain antibody levels. For the most part the circulating influenza-specific T cell and serum antibody levels in the population at one year post-pandemic were not different between cases and controls, suggesting that natural infection does not lead to higher long term T cell and antibody responses in donors with pre-existing immunity to influenza. However, based on the responses of one longitudinal donor, it is possible for a small population of pre-existing cross-reactive memory CD8 T cells to expand rapidly following infection and this response may aid in viral clearance and contribute to a lessening of disease severity

Impaired emotional facial expression recognition in alcohol dependence: do these deficits persist with midterm abstinence?

BACKGROUND: Emotional facial expression (EFE) decoding has been repetitively shown to be impaired in alcoholic inpatients. The present study aimed to replicate and extend previous findings on EFE recognition deficits in alcoholism. METHODS: Alcoholic and control participants' performances were compared on an EFE decoding task with a transversal and a longitudinal design. More specifically, 49 alcoholic individuals were recruited at a long-stay postdetoxification treatment center at the third or fourth week of their detoxification process. Twenty-two of them [abstinent alcoholic participants (AA)] were met at the end of their hospitalization process, 2 months later. The 27 remaining patients [dropping alcoholic participants(AD)] dropped out from treatment before the second meeting. A control group (C) of 22 participants was constituted, and assessed twice with the same average time as AA between the 2 assessments. The 3 groups were similar regarding age, sex, and education level. Participants were presented at both times with an EFE decoding test consisting of 16 photographs depicting EFE of happiness, anger, disgust, and sadness. RESULTS: The results corroborated previous findings highlighting more EFE decoding deficits in alcoholic participants compared with control participants, with no improvement after 3 months of abstinence. Transversal analyses further evidenced more EFE decoding difficulties in AD than in AA compared with controls. CONCLUSIONS: EFE decoding deficits in alcoholism persist with midterm abstinence. Alcoholic patients who dropped from treatment had the worst EFE decoding performance at baseline. Emotional facial expression decoding deficit could have a prognostic value in alcohol dependence.Journal ArticleResearch Support, Non-U.S. Gov'tFLWINinfo:eu-repo/semantics/publishe