Abstract

There are millions of influenza infections annually, causing a range of illness severity. Although annual influenza vaccinations reduce infection and transmission, vaccine efficacy rates vary from 30-60%, highlighting the need for improved tools to predict influenza susceptibility and transmission. Household cohorts such as the Southern Hemisphere Influenza Vaccine Effectiveness and Response Study (SHIVERS IV) cohort help identify factors contributing to influenza infection and transmission. In this study, households are enrolled, and blood samples are taken before, during, and after transmission events. To capture all asymptomatic infections all household members are PCR tested every 3 days after a confirmed household infection. To identify immune correlates of protection and transmission, we performed high dimensional flow cytometry on the baseline samples of all household members examining both innate and adaptive immune markers. We hypothesize that those who transmit influenza to household contacts will have weaker post infection innate activation profiles compared to those who never spread influenza to their household contacts. Furthermore, those that are protected from influenza infection after exposure to a household contact, we predict will have higher rates of polyfunctional CD4+ T cells. Future plans include transcriptional and TCR repertoire profiling of transmitting and protected individuals.

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