Full Name
Hannah Stacey
Job Title
PhD Student
McMaster University
City (Work Address)
State/Province/County (Work Address)
Speaker Bio
Hannah is a 4th year PhD candidate in the Miller lab at McMaster University. She completed her Bachelor of Health Sciences degree at McMaster in the Biomedical Discovery and Commercialization Program in 2018 before starting a direct -entry PhD with Dr. Matthew Miller. During the pandemic Hannah was involved in several SARS-CoV-2 studies, largely focused on antibody responses following vaccination and infection. Her PhD research investigated unique neutrophil Fc effector functions induced by mucosal (IgA) antibodies. Most recently, she has examined how different seasonal influenza vaccine formulations can influence immune responses in children. Outside of the lab, Hannah enjoys cycling or sitting down with a nice glass of red wine and a good book
Abstract Title
Investigating the influence of influenza vaccine formulation on Original Antigenic Sin responses in a longitudinal cohort of children
Abstract Summary
Annually, influenza virus infection results in 3-5 million serious illnesses, with children representing a large proportion of those affected. Several seasonal influenza vaccines are available, including inactivated (IIV), live-attenuated (LAIV), and adjuvanted inactivated influenza vaccines (AIIVs). Seasonal vaccine effectiveness (VE) varies, and this variability has, in-part, been attributed to ‘Original Antigenic Sin’ (OAS). OAS describes a phenomenon wherein the first exposure to influenza virus shapes subsequent immune responses to vaccinations or infections. Antibody titers against the first strain an individual is exposed to are boosted through repeated exposure to antigenically related strains. In the context of seasonal vaccination, OAS may be detrimental, as antibodies against conserved, but non-neutralizing epitopes are boosted. However, OAS may be beneficial when targeting conserved epitopes. No studies have directly examined the impact vaccine formulation on OAS in humans. This question is especially important in the context of childhood vaccinations, since children are a high-risk group for serious influenza virus infections. A subset of serum from two cluster-randomized control trials comparing LAIV and IIV, and AIIV and IIV in Hutterite children across three consecutive influenza seasons was assessed for vaccine strain specific and broadly-neutralizing antibodies (bnAbs). Successive vaccination with IIV was observed to cause the most profound OAS. AIIV overcame OAS, particularly in response to H3 vaccine components, and induced the strongest bnAbs response in children. These findings will inform the selection of seasonal influenza vaccines, and the design of next generation influenza vaccines that are most suitable for use in children.
Hannah Stacey