Sr. Scientist, Conjugation Development



San Carlos, CA, USA
Posted on Tuesday, January 30, 2024
Company Profile:
Vaxcyte, Inc. (Nasdaq: PCVX) is a vaccine innovation company engineering high-fidelity vaccines to protect humankind from the consequences of bacterial diseases. The Company is developing broad-spectrum conjugate and novel protein vaccines to prevent or treat bacterial infectious diseases. Vaxcyte’s lead candidate, VAX-24, is a 24-valent, broad-spectrum, carrier-sparing pneumococcal conjugate vaccine (PCV) being developed for the prevention of invasive pneumococcal disease (IPD). The Company is re-engineering the way highly complex immunizations are made through modern synthetic techniques, including advanced chemistry and our exclusively licensed XpressCFTM cell-free protein synthesis platform. Unlike conventional cell-based approaches, the Company’s system for producing difficult-to-make proteins and antigens is intended to accelerate its ability to efficiently create and deliver high-fidelity vaccines with enhanced immunological benefits. Vaxcyte’s pipeline also includes VAX-31, a 31-valent PCV candidate; VAX-A1, a prophylactic vaccine candidate designed to prevent Group A Strep infections; VAX-PG, a therapeutic vaccine candidate designed to slow or stop the progression of periodontal disease; and VAX-GI, a vaccine program designed to prevent Shigella. The Company is driven to eradicate or treat invasive bacterial infections, which have serious and costly health consequences when left unchecked. For more information, visit
Vaxcyte, headquartered in San Carlos, CA, went public in June 2020 and currently has a team of approximately 180 employees and anticipates continued, significant growth. Following equity offerings in October 2022 and April 2023, which generated over $1.1 billion in net proceeds, the Company’s balance sheet is further strengthened to advance its pipeline of novel vaccines, including VAX-24. These financings followed positive data readouts from Vaxcyte’s Phase 1/2 proof-of-concept study evaluating VAX-24 in adults aged 18-64 and Phase 2 study in adults 65 and older. The Company believes these results support a best-in-class potential for VAX-24, which was designed to replace the current standard-of-care in adults and children. VAX-24 is being investigated for the prevention of IPD, which can be most serious for infants, young children, older adults and those with immune deficiencies or certain chronic health conditions. Given the global impact of pneumococcal disease remains significant, the public health community continues to advocate for vaccines that can offer broader protection to prevent IPD. Vaxcyte’s PCV franchise, consisting of VAX-24 and VAX-31, is designed specifically to address this need and has the potential to deliver the broadest protection for this very serious disease. We believe that our PCVs could receive regulatory approval based on successful completion of clinical studies utilizing well-defined surrogate immune endpoints, consistent with how other PCVs have obtained regulatory approval in the past, rather than requiring clinical field efficacy studies.
Vaxcyte is looking for a Senior Scientist, Conjugation Development. For the next 1-2 years the candidate’s primary responsibility will be to contribute to process characterization efforts for the company’s pneumococcal conjugate vaccine program; after that, the candidate will work on conjugation process development for Vaxcyte’s pipeline programs. Specifically, this will include preparation, purification, and analytical characterization of chemically modified polysaccharides and polysaccharide-protein conjugates. The ideal candidate will have significant laboratory experience and an excellent understanding of analytical chemistry principles. The successful candidate will be expected to design, execute, and troubleshoot experiments with minimal guidance. The candidate will also contribute when needed to a range of related areas such as analytical development and stability studies. Responsibilities will additionally include record management, data presentation at group meetings, authorship of laboratory protocols and development reports, communication with external organizations during tech transfer, and assumption of a leadership role in collaborative studies with other members of the conjugation group.

Essential Functions:

  • Optimize and troubleshoot multi-step syntheses of protein-polysaccharide conjugates.
  • Purify polysaccharides and conjugates using a variety of methods including dialysis, size-exclusion chromatography, and tangential flow filtration (TFF).
  • Analyze polysaccharides and conjugates with a variety of analytical methods. Develop new laboratory workflows and analyses beyond established procedures when appropriate.
  • Advise team members on experimental design, interpretation of results, and troubleshooting.
  • Model and train team members on best practices for adherence to protocols and data management.
  • Serve as a subject matter expert during tech transfer of conjugation processes to contract manufacturing organizations.
  • Maintain highly organized records to enable optimization and assessment of reproducibility.
  • Attend team meetings ready to provide updates on conjugation development progress.


  • PhD in Chemistry, Biochemistry, or related field with 5+ years of industry experience, MS with 8+ years, or BS with 10+ years of experience.
  • Strong biochemistry and organic chemistry knowledge base underpinning several years’ experience preparing bioconjugates.
  • Subject matter expertise with small- and large-scale techniques for purification of bioconjugates, including tangential flow filtration.
  • Subject matter expertise with techniques for bioconjugate analysis such as colorimetric assays, HPLC, and SEC-MALS.
  • Sufficient knowledge of analytical principles to develop fit-for-purpose analytical methods as needed and provide cross-functional feedback on draft analytical methods.
  • Experience with Design of Experiments is desirable.
  • Experience with chemical modification of polysaccharides is desirable.
  • Experience implementing and/or using electronic notebooks is desirable.
  • Attention to detail and excellent organizational skills.
  • Strong interpersonal skills: ability to communicate effectively both verbally and in written formats.
  • Self-starter: ability to work in a fast-paced, cross-functional environment and collaborate effectively with other team members.
  • Enthusiasm to learn the new skills and techniques necessary to tackle problems outside of current area of expertise.
  • All Vaxcyte employees require vaccination against COVID-19.
Reports to: Group Leader, Conjugation Development
Location: San Carlos, CA
The compensation package will be competitive and includes comprehensive benefits and an equity component.
Salary Range: $145,000 – $162,000
Send resumes to:
Vaxcyte, Inc.
825 Industrial Road, Suite 300
San Carlos, CA 94070
We are an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability or veteran status.