Principal Scientist, Virology & Immunology

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

The Opportunity

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.

Key Responsibilities

• 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, TCID50, RT-qPCR, reverse genetics, hemagglutination 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 excellence and accountability.
• Biosafety and Laboratory Operations: Conduct authorized laboratory research in accordance with applicable biosafety, animal welfare, and documentation requirements. Support laboratory readiness, risk assessments, and training for work in BSL-2, enhanced BSL-2, and BSL-3 environments as assigned, partnering with biosafety and laboratory operations teams to maintain safe and compliant research practices.

Qualifications

• PhD in Virology, Immunology, Microbiology, Molecular Biology, or a related life sciences discipline, with at least five years of relevant postdoctoral or professional research experience.
• Strong expertise in classical and molecular virology, including hands-on experience developing, optimizing, and troubleshooting quantitative cell-based assays.
• Experience with infectious-virus culture and titration, neutralization assays, molecular virology techniques, and at least one pseudovirus or reporter-virus platform.
• Experience designing and interpreting preclinical vaccine or infectious-disease studies and integrating virological and immunological findings.
• Strong experimental design, statistical analysis, and data visualization skills, including proficiency with GraphPad Prism or equivalent software.
• Demonstrated scientific leadership, project coordination, and experience mentoring or training laboratory colleagues.
• A record of scientific achievement through publications, patents, assay or platform development, or contributions to research program advancement.
• Excellent written and verbal communication skills and the ability to collaborate across cross-functional, multicultural, and international teams.
• Practical experience working safely with infectious agents in BSL-2 laboratories and a strong commitment to biosafety, data integrity, and reproducible science.

Preferred Qualifications

• Experience in seasonal or pandemic influenza research, including HA/NA biology, antigenic characterization, influenza vaccine development, or influenza challenge models.
• Experience with both HIV-1/lentiviral and VSV-based pseudovirus platforms, BSL-3 laboratories, or ferret respiratory-virus models.
• Knowledge of functional antibody assays, including ADCC and neuraminidase inhibition, or cellular immunology techniques such as flow cytometry and ELISpot.
• Experience with antigenic cartography, sequence-based analysis, or computational tools such as R or Python.
• Experience with CRO oversight, assay technology transfer and qualification, external scientific partnerships, or regulatory-supporting research.

Working Environment

This is a fully onsite, laboratory-based position requiring five days per week at our Waltham, Massachusetts site. The role involves authorized laboratory work, including high-containment activities as assigned, and requires completion of applicable site-specific training and occupational-health requirements. Occasional domestic or international travel may be required.

CSL Seqirus is committed to scientific excellence and advancing innovative vaccines that help protect public health. Join our team and contribute your expertise to meaningful research and vaccine development.

The expected base salary range for this position at hiring is $145,000 - $180,000. Please note this salary range reflects the minimum and maximum base pay that CSL expects to pay for this position at the time of this posting in MA. Individual base salary for a successful candidate is determined by qualifications, skill level, experience, competencies and other relevant factors. In addition to base salary, total compensation for this role may also include incentive compensation and equity.

About CSL Seqirus

CSL Seqirus is part of CSL. As one of the largest influenza vaccine providers in the world, CSL Seqirus is a major contributor to the prevention of influenza globally and a transcontinental partner in pandemic preparedness. With state-of-the-art production facilities in the U.S., the U.K. and Australia, CSL Seqirus utilizes egg, cell and adjuvant technologies to offer a broad portfolio of differentiated influenza vaccines in more than 20 countries around the world.

To learn more about CSL, CSL Behring, CSL Seqirus and CSL Vifor visit https://www.csl.com/ and CSL Plasma at https://www.cslplasma.com/.

Our Benefits

For more information on CSL benefits visit How CSL Supports Your Well-being | CSL.

You Belong at CSL

At CSL, Inclusion and Belonging is at the core of our mission and who we are. It fuels our innovation day in and day out. By celebrating our differences and creating a culture of curiosity and empathy, we are able to better understand and connect with our patients and donors, foster strong relationships with our stakeholders, and sustain a diverse workforce that will move our company and industry into the future.

 To learn more about inclusion and belonging visit https://www.csl.com/careers/inclusion-and-belonging

Equal Opportunity Employer

CSL is an Equal Opportunity Employer. If you are an individual with a disability and need a reasonable accommodation for any part of the application process, please visit https://www.csl.com/accessibility-statement.

Watch our ‘On the Front Line’ video to learn more about CSL Seqirus