Principal Scientist, Virology & Immunology

CSL Seqirus | Waltham, MA | Onsite, 5 days per week

CSL Seqirus is seeking a Principal Scientist to join our Research Virology and Immunology (RVI) team in Waltham, MA. Reporting to the Director, Vaccine Virology & Immunology, you will provide scientific leadership and hands‑on laboratory expertise to advance seasonal and pandemic influenza vaccines, support existing products, and evaluate new respiratory‑virus vaccine opportunities.

This role offers the opportunity to lead research programs, develop and optimize virology and immunology assay platforms, and translate complex scientific data into actionable recommendations that support vaccine development. You will collaborate across research and development teams, mentor colleagues, and contribute to innovative solutions addressing important public health needs.

• Scientific Leadership and Program Delivery: Lead assigned vaccine research programs as a virology subject‑matter expert, translating scientific priorities into experimental strategies, milestones, and deliverables. Partner with research leadership, project managers, and cross‑functional teams to advance programs from early concept evaluation through preclinical development while maintaining hands‑on involvement in critical experiments and scientific decision‑making.
• Virology and Immunology Assay Development: Design, develop, optimize, and troubleshoot virological and immunological assays to support vaccine research and product development. Techniques may include live‑virus and pseudovirus neutralization, infectious‑virus culture and titration, plaque and focus‑forming assays, TCID
  50, RT‑qPCR, reverse genetics, hem agglutination inhibition (HAI), microneutralization, ELISA, neuraminidase inhibition, and functional antibody assays such as antibody‑dependent cellular cytotoxicity (ADCC).
• Preclinical and Translational Vaccine Research: Design and interpret preclinical immunogenicity and protection studies using relevant animal models, including ferrets and rodents, in collaboration with in vivo specialists and external partners. Investigate vaccine‑induced immunity, antigenic breadth, durability of responses, and the contributions of hemagglutinin, neuraminidase, and adjuvants to vaccine performance. Integrate animal‑study findings with human serology and virology data to inform vaccine development and product differentiation.
• Data Analysis and Scientific Communication: Apply rigorous experimental design, appropriate controls, and quantitative analysis to generate reproducible, high‑quality data. Interpret neutralization, titration, sequence, and antigenic datasets using appropriate statistical and analytical tools. Communicate findings, study limitations, and recommendations through scientific reports, presentations, publications, and contributions to regulatory documentation and intellectual property activities.
• External Collaboration and Technology Transfer: Provide scientific oversight of contract research organizations (CROs) and external collaborators, including study design, technical troubleshooting, data review, and delivery of project objectives. Support assay transfer, method qualification, and cross‑site comparability while maintaining scientific ownership of assigned methods. Evaluate emerging technologies, scientific literature, and external research opportunities to inform program strategy.
• Technical Mentorship and Team Development: Mentor and train scientists and research associates, provide technical guidance, and promote knowledge sharing and cross‑training. Contribute to research planning, platform development, and continuous improvement while fostering a collaborative culture of scientific…