Rebecca Morse

PhD thesis: Investigating SARS-CoV-2 Immune Imprinting in People Living with HIV

‘Immune imprinting’, or ‘original antigenic sin’, describes how the immune system's initial response to a viral infection shapes future responses to related strains. For instance, during the 2009 H1N1 influenza pandemic, older individuals exposed to a similar H1N1 strain in childhood were better protected from severe disease. This concept is also observed in healthy people vaccinated against the original SARS-CoV-2 strain, but research is limited for immunocompromised populations and those with delayed vaccine access.

My PhD research will investigate imprinting mechanisms in a Nigerian cohort – including people living with HIV (PLWH) – who were exposed to SARS-CoV-2 variants before vaccines became available. I will utilise 10X genomics to sequence B cell receptor repertoires and live-virus cell-based assays to evaluate antibody neutralisation.

Elucidating the impacts of variant exposures, delayed vaccinations, and altered immunity due to HIV co-infection will improve our understanding of the global SARS-CoV-2 immunity landscape and inform vaccination strategies.

Who or what inspired you to pursue your research interests?

My mother’s cancer diagnosis and Aaron Mathieu’s biology lectures sparked my interest in immunology research. Supported by Professors Janice Knepper, Mary Regina Boland, and Jim Riley during my undergraduate studies, I became interested in studying mechanisms of disease to improve therapeutic development. The COVID-19 pandemic drove me to focus this interest on individuals at higher risk of disease despite vaccination. I received a Fulbright Award with Professor Arnaud Didierlaurent to investigate innate immune responses to SARS-CoV-2 vaccination in people taking immunosuppressants. During my PhD, I will continue my work with Professor Ravi Gupta to translate academic research into clinical progress for those at higher risk of disease.