Postdoctoral Fellow – Bacterial Diversity and Vaccine Coverage
- United States - New York - Pearl River
Use Your Power for Purpose
Clostridioides difficile infection (CDI) represents an urgent public health threat, causing severe morbidity and mortality worldwide. Despite antibiotic treatments, recurrence remains common due to disruption of the gut microbiota, highlighting a critical need for effective vaccines for primary prevention. Pfizer is committed to advancing vaccine strategies that address this unmet medical need. In this role, you will apply cutting-edge microbiology, genomics, and computational science to better understand bacterial virulence and Pfizer’s vaccine-induced protection, directly supporting efforts to reduce the global burden of CDI.
What You Will Achieve
As a Postdoctoral Fellow within Pfizer Vaccines, you will lead an interdisciplinary research project focused on understanding the variability of Clostridioides difficile toxins and its impact on virulence and vaccine-induced breadth of neutralization. You will be trained to operate with increasing scientific independence while collaborating across microbiology, immunology, bioinformatics, and data science disciplines. This work is expected to generate high-impact publications and provide a strong foundation for future scientific leadership in academia or industry.
How You Will Achieve It
Analyze a large, contemporary global collection of C. difficile clinical isolates using whole-genome sequencing to define tcdA and tcdB diversity.
Relate toxin genotypic variation to toxin production, potency, and cytotoxicity using functional and phenotypic assays.
Execute toxin neutralization assays to evaluate the breadth of protection conferred by Pfizer’s C. difficile vaccine candidates.
Collaborate with a multi-disciplinary team, apply AI/ML-based computational modeling approaches to integrate high-dimensional genotypic and phenotypic datasets.
Work with mentors to interpret complex datasets to identify toxin-centric biomarkers associated with disease severity and virulence.
Present findings through scientific manuscripts, internal reviews, and conference presentations.
Ensure all tasks and responsibilities are carried out according to scientific, ethical and regulatory standards.
Here Is What You Need (Minimum Requirements):
PhD in Microbiology, Molecular Biology, Immunology, or a related discipline (completed by start date).
Pre-doctoral or post-doctoral research investigating microbial pathogenesis, immunology, or molecular microbiology and demonstrating a broader technical expertise working in a biosafety level two (or higher) laboratory.
Demonstrated experience leading scientific investigations, including analysis and interpretation of complex biological datasets.
Excellent written and verbal communication skills with at least:
one accepted first-author publication and external conference oral presentation if pursuing a first postdoctoral post, or
two accepted first-author publications and external conference oral presentations if pursuing a second postdoctoral post.
Demonstrated experience participating in a collaborative, interdisciplinary scientific research effort.
Willingness to make a minimum 2-year commitment.
Less than 2 years post-doctoral experience.
Provide two letters of recommendation.
Bonus Points If You Have (Preferred Requirements):
Experience with whole-genome sequencing analysis, comparative genomics, or phylogenetics.
Hands-on experience with functional cell-based assays, cytotoxicity assays, or toxin neutralization models.
Familiarity with machine learning, multivariate statistics, or integrative data analysis approaches (e.g., R or Python).
Experience working with anaerobic or spore-forming bacteria.
PHYSICAL/MENTAL REQUIREMENTS
The position includes basic laboratory and office physical requirements, including standing, sitting, and routine laboratory work, and encompasses research activities as outlined in the posting and may include additional research efforts to support vaccine development beyond the scope described.
NON-STANDARD WORK SCHEDULE, TRAVEL OR ENVIRONMENT REQUIREMENTS
- Schedule: Occasional weekend and holiday work may be required to support experimental needs. Travel to scientific conferences and/or business meetings is expected approximately 5% of the time.
- Relocation: support available
- Work Location Assignment: On Premise
- Last date to apply May 4th, 2026
Relocation assistance may be available based on business needs and/or eligibility.

Candidates must be authorized to be employed in the U.S. by any employer.
U.S. work visa sponsorship (such as TN, O-1, H-1B, etc.) is not available for this role now or in the future.

Sunshine Act
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EEO & Employment Eligibility
Pfizer is committed to equal opportunity in the terms and conditions of employment for all employees and job applicants without regard to race, color, religion, sex, sexual orientation, age, gender identity or gender expression, national origin, disability or veteran status. Pfizer also complies with all applicable national, state and local laws governing nondiscrimination in employment as well as work authorization and employment eligibility verification requirements of the Immigration and Nationality Act and IRCA. Pfizer is an E-Verify employer. This position requires permanent work authorization in the United States.
Pfizer endeavors to make www.pfizer.com/careers accessible to all users. If you would like to contact us regarding the accessibility of our website or need assistance completing the application process and/or interviewing, please email disabilityrecruitment@pfizer.com. This is to be used solely for accommodation requests with respect to the accessibility of our website, online application process and/or interviewing. Requests for any other reason will not be returned.
Breakthroughs that change patients’ lives
Research confirms what intuition tells us: that purpose-driven companies perform better, are more innovative, attract and retain the best people, and know how to unleash the power of those people. Pfizer’s purpose—Breakthroughs that change patients' lives—fuels everything we do and reflects our passion for building on our legacy as one of the greatest contributors of good to the world.
Each word in our purpose has meaning and reflects the value we strive to bring to patients and society:
“Breakthroughs” - These are the innovations, scientific and commercial, that we seek to deliver every day. All colleagues, regardless of role, level or location, strive for breakthroughs every day.
“Change” - We want to do more than simply improve patients’ medical conditions; we want to dramatically change their lives for the better.
“Patients’ lives” - We consider not only patients, but everyone they touch—including their families, caregivers, and friends—and everything they love to do. It’s an intentionally holistic view.
Our purpose ensures that patients remain at the center of all we do. We live our purpose by sourcing the best science in the world; partnering with others in the healthcare system to improve access to our medicines; using digital technologies to enhance our drug discovery and development, as well as patient outcomes; and leading the conversation to advocate for pro-innovation/pro-patient policies.
Every decision we make and every action we take is done with the patient in mind—and to nurture an environment where breakthroughs can thrive.
Our Values
To fully realize Pfizer’s purpose, we have established a clear set of expectations regarding “what” we need to achieve for patients and “how” we will go about achieving those goals.
The “how” is represented by four simple, powerful values—courage, excellence, equity, and joy—that define our company and our culture.
Courage: Breakthroughs start by challenging convention, especially in the face of uncertainty or adversity. This happens when we think big, speak up, and are decisive.
Excellence: We can only change patients’ lives when we perform at our best together. This happens when we focus on what matters, agree who does what, and measure our outcomes.
Equity: We believe that every person deserves to be seen, heard, and cared for. This happens when we are inclusive, act with integrity, and reduce healthcare disparities.
Joy: We give ourselves to our work, but it also gives to us. We find joy when we take pride, recognize one another, and have fun.
Pfizer Research & Development
Pfizer Research & Development serves as the beating heart of Pfizer's trailblazing product pipeline, the essence of our mission to bring life-changing medicines to the world.
With an unwavering commitment to innovation, we use a multidisciplinary approach that blends scientific expertise, cutting-edge technologies, and strategic collaborations, igniting a powerful engine that propels groundbreaking discoveries into life-saving treatments for patients in need.
Through our relentless pursuit of progress, we envision a future where cutting-edge medicines pave the way to healthier, happier lives worldwide.
Benefits at Pfizer
Pfizer offers competitive compensation and benefits programs designed to meet the diverse needs of our colleagues. Our Pay for Performance Philosophy and Practices reward colleagues based on the contributions they make to our business.
Our Competitive Benefits Programs help our colleagues by:
- Promoting Health and Wellness to help colleagues maintain and improve their physical and mental wellbeing. Pfizer offerings include health and disability insurance, preventative health programs, medical screenings, free or reduced-cost vaccinations, discounts on Pfizer products, mental health support, nutrition and fitness counseling and more.
- Strengthening Colleagues’ Financial Security by providing company contributions to retirement plans, life insurance and financial planning education to help colleagues achieve their financial goals.
- Providing Benefits and Time off for the Moments that Matter to ensure Pfizer colleagues have the time away from the office to recharge, recover and return to work as the best version of themselves. Vacation, Holiday time and Sick time are just the beginning, with a 12 week parental leave policy for both parents of a new born, 10 day of caregiver leave for those times when your family needs you whether it’s a child, spouse or parent, bereavement leave, and additional country-specific programs.
- And so much more, depending on your country and site, Pfizer offers childcare facilities or discount programs, on-site health and/or fitness centers, movement and mindfulness solutions, “Log in for your Day” work flexibility and so much more.
For U.S. based jobs, view an overview of Pfizer’s U.S. benefits program (opens in a new window)