Associate Upstream Processing Scientist Jobs in California

Senior Associate Scientist (Contract), Upstream Polysaccharide Process Development – Vaxcyte

Posted on: June 04, 2026

The Development organization is comprised of four Process teams: Protein, Polysaccharide, Conjugate Drug Substance (Conjugation), and Drug Product. These Process Development teams are supported by Analytical Development and Formulation Development teams. Vaxcyte is looking for a Senior Associate Scientist (contract) with experience in microbial fermentation and upstream processing to join the Upstream Polysaccharide Process Development team. The candidate will be responsible for collaboration on experimental design and execution of experiments to further develop and optimize upstream processes for polysaccharide manufacturing using microorganisms. The successful candidate will have practical laboratory experience related to microbial fermentation processes and eager to utilize and learn new laboratory skills. The role will require >50% time in the lab and this person will be able to independently detail experimental procedures/results in written and presentation formats. The successful candidate may interface closely with the cross-functional team, write detailed technical reports, present experimental results internally, and may potentially interface with external CMO partners.

Essential Functions:

• Support in study design, execute, and analyze experiments for upstream polysaccharide for bacterial fermentation (BSL2) and vaccine production processes.
• Execute experiments to develop the upstream process parameters (e.g., media, feed, pH, temperature, dissolved oxygen, agitation, etc.) and to enhance product yield, quality, and consistency.
• Perform microbiology related work including plating, colony selection, Gram staining and cell enumeration on microscope.
• Perform fermentation vessel assembly and script writing for process automation and execute fermentation experiment in shake-flask and lab scale bioreactors.
• Prepare media and buffer as needed for experiments.
• Operate and maintain instrumentation for bacterial fermentation and primary recovery (centrifugation, filtration, etc.) of bacterial polysaccharides utilizing aseptic techniques.
• Support analytical method execution including optical density, residual metabolites and polysaccharide concentration and other relevant analytical techniques.
• Keep accurate and current records of research and/or project related activities in laboratory notebooks and Electronic Lab Notebook.
• Prepare and review protocol, technical reports, SOPs, and batch records.
• Present and communicate scientific data and results to internal stakeholders.
• Be an outstanding teammate and collaborate effectively with cross functional team members.
• and collaborate effectively with downstream, analytical, and manufacturing teams within Polysaccharide Development and Manufacturing team to ensure seamless technology transfer and process integration.

Requirements:

• MSc in Chemical/Biochemical Engineering, Biotechnology, or similar degree with a minimum of 3 years of relevant industry experience, or BSc with a minimum of 5 years of relevant industry experience.
• Experience in handling microorganisms with proper aseptic techniques to perform upstream processing related work in flasks/bioreactors.
• Hands‑on experience and theoretical understanding of key processing operations such as microbial culture, fermentation process, microbial media, and process optimization and relevant analytical technologies; experience with depth filtration, continuous centrifugation is a plus.
• Develop and optimize scripts for instrumentation, including Ambr® systems, to enhance efficiency and automate processes, leveraging programming languages such as Python or R is a plus.
• Experience with Design of Experiments (DoE) principles and DoE software.
• Process characterization experience is a plus.
• Cell banking expertise, colony selection and genetic analysis of recombinant strains is a plus.
• Proficiency with computer programs such as Microsoft Excel, Word, PowerPoint, Visio and JMP.
• Working knowledge of GMP requirements.
• Proven ability to succeed in a cross-functional team environment, effectively managing multiple projects and contributing to team outcomes.
• Strong interpersonal skills, with excellent written and verbal communication abilities.

Reports to: Senior Scientist, Upstream Polysaccharide Process Development