The Vaccine Design & Development Laboratory (DDL) Team

Meet the team

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Christopher L. Parks, Ph.D., Associate Vice President of Viral Vaccines and Head of the Vaccine Design & Development Laboratory

Christopher Parks, Ph.D., is a member of IAVI’s Senior Leadership Team and leads the DDL. He manages preclinical research and development activities at the DDL for IAVI’s emerging infectious diseases program. The DDL specializes in preclinical development of vaccines based on vesicular stomatitis virus vaccine delivery vectors, including work on vaccines for Lassa fever, Sudan Ebola virus, Marburg virus, HIV, and SARS-CoV-2. Parks has been a member of IAVI since 2007.


Christopher Cooper, Ph.D., Director, Viral Vaccines

Christopher Cooper, Ph.D., leads the DDL’s scientific teams’ strategy. He oversees the execution and direction of preclinical studies, setting scientific objectives, and making sure that collaborations and programs are aligned with IAVI’s mission and organizational goals.

Joanne De Stefano

Joanne De Stefano, Director, Preclinical Program & Laboratory Operations 

Joanne De Stefano has over 30 years of experience in the preclinical science field and viral vaccine discovery. Joanne has been with IAVI since 2006 and leads the Preclinical Program and oversees DDL Operations. She is also an adjunct professor at the City University of New York (CUNY) at LaGuardia Community College, where she teaches research veterinary technology courses. 

Meet The Team Filler

Anne Ercolini, Ph.D., Associate Director, Viral Vaccine Programs 

Anne Ercolini, Ph.D., has been with IAVI since 2019 and serves as the associate director of the Viral Vaccines Program.  In this role, she is responsible for managing several vaccine discovery and development programs for HIV and emerging infectious diseases such as Lassa fever, Marburg virus disease, and COVID.  

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Gavin Morrow, Ph.D., Associate Director, Preclinical Partnerships

Gavin Morrow, Ph.D., initially joined IAVI in 2007 as a research scientist working in IAVI’s immunobiology group, before taking on the role of associate director of vector immunobiology at the DDL, where he led a group of scientists responsible for implementing preclinical studies that help support IAVI’s replicating vector program. Now, as associate director of preclinical partnerships, Morrow is responsible for overseeing the important relationships IAVI has with its external preclinical partners.

Meet The Team Filler

Alexei Carpov, Analytical Scientist I, Vector Evaluation and Quality Control 

Alexei Carpov joined IAVI in 2007. He started working in the protein purification and analytics group to purify and characterize different protein immunogens in the HIV program as potential vaccine candidates for use in preclinical studies. Currently, Carpov is working on upstream and downstream processes, as well as characterization and analysis of Lassa fever, Marburg virus disease, Sudan Ebola virus, SARS-COV-2, and HIV vesicular stomatitis virus (VSV) vaccine candidates. Carpov has designed different VSV particle assays to characterize VSV-vaccine candidates. Additionally, he’s responsible for protein production regarding upstream, downstream, characterization, and final analysis of all protein constructs in DDL.

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Yesle T. Choi, Research Associate II, Vector Immunobiology 

YesleChoi joined IAVI in 2017 as a research associate in the DDL’s Immunobiology Team. She is working primarily on cell cultivation and counting, cell isolation, ELISA, and Luminex® assay. Choi runs experiments to assess immune responses to vesicular stomatitis virus vaccine vectors in preclinical studies.


Kezhi Dai, Ph.D., Analytical Scientist II, Vector Design 

Kezhi Dai, Ph.D., has been a member of the Vaccine Vector Design and Development Team since 2021. He is responsible for design and development of recombinant vesicular stomatitis virus (rVSV) vectors, mainly involving the design and cloning of rVSV vectors and production and characterization of rVSV-based vaccine candidates.

Megan Downey

Megan Downey, LVT, RLAT, Veterinary Technician I, Preclinical 

Megan Downey joined IAVI’s preclinical team in 2021.  As part of her role, she coordinates and conducts preclinical testing for the DDL and she works closely with the immunobiology team on various preclinical projects.  She is part of the IAVI Wellness Committee and also the co-chair of the DDL safety committee, where she helps oversee and manage the safety program. 

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Fuqiang Geng, Ph.D., Analytical Scientist I, Vector Evaluation and Quality Control  

Fuqiang (Frank) Geng, Ph.D., joined the DDL in 2023 as a member of the Vector Evaluation and Quality Control Team. His primary focus is to improve the vesicular stomatitis virus-based vaccine platform for various programs such as Lassa fever, Marburg virus disease, Sudan Ebola virus, SARS-COV-2, and HIV. Geng is currently developing innovative assays for a more comprehensive characterization of vaccine products.

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Cecelia Harold, Ph.D., Analytical Scientist I, Vector Evaluation and Quality Control 

Cecelia Harold, Ph.D., joined the DDL in 2023 and is a member of the Vector Evaluation & Quality Control Team. In her role as a scientist, she is responsible for multiple activities such as evaluating viral vectors produced at the DDL, developing new assays to detect live virus from tissues, and expanding sequencing capabilities.

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Fuxiang Hou, Analytical Scientist I, Vector Design 

Fuxiang Hou joined the DDL in 2017. As a member of Vaccine Vector Design team, she is responsible for multiple activities such as developing assays to evaluate the potency and immunogenicity of vaccine candidates. Hou also works to construct, propagate, purify, and characterize viral vectors.

Meet The Team Filler

Michelle Lam, M.Sc., Graduate Research Associate 

Michelle is a Ph.D. candidate in the Department of Molecular and Cellular Biology at SUNY Downstate Health Sciences University. Her thesis work, conducted at the DDL, investigates mucosal immune responses after intranasal vaccination. 

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Shui Li, Research Associate II, Vector Design

Shui Li is a member of the Vaccine Vector Design Team at the DDL. After starting as an intern, he transitioned into a full-time position with the group. Li optimizes vaccine candidates to work in IAVI’s vesicular stomatitis virus platform and develops and characterizes them to move on to the next phases of a program.  


Charlie Liu, Research Associate I, Vector Immunobiology 

Charlie Liu is a member of the Immunobiology Team at the DDL. He joined the DDL in 2022 and is responsible for performing assays such as ELISAs, Meso Scale discovery, and enzyme-linked immunospot (ELISPOT) assays.

Silvana Martinez

Silvana Martinez, Laboratory Operations Specialist

Silvana is a member of the operations team at the DDL. She joined the DDL in 2020 as an intern in the vectors design team and then transitioned to a full-time position at the lab. In her role, she is responsible for supporting the continuous and safe operations of the lab.

Jennifer Martinez

Jennifer Martinez, LVT, RLATG, Senior Manager, Pre-clinical  

Jennifer Martinez is the Manager of the Pre-clinical Team and oversees all of IAVI’s in-house projects. She has been part of the DDL team for over 13 years. She has extensive experience in pre-clinical work and works closely with IAVI’s Immunobiology Team on a variety of pre-clinical projects. 

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Karina Peregrina, Sr. Research Associate I, Vector Immunobiology 

Karina Peregrina became a member of the Immunobiology Team at the DDL in 2023. In her role, she is responsible for being a pinch hitter for the various immunoassays run by the immunology team such as ELISA and Meso Scale discovery. 

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Thomas Postler, Ph.D., Principal Scientist, Vector Immunobiology

Thomas Postler, Ph.D., has been a principal scientist and lead of the Immunobiology Team at the DDL since 2023. Before joining IAVI, Thomas conducted basic research in physiology, virology, and immunology at the University of Pennsylvania, Harvard University, and Columbia University. His expertise includes transcriptional regulation of immune cells, long non-coding RNAs, transcriptomics, macrophage and T-cell biology, and viral taxonomy.

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Suzane Ramos da Silva, Ph.D., Principal Scientist, Vector evaluation and Quality Control

Suzane Ramos da Silva obtained her Ph.D. in pathology and dedicated her career to studying oncogenic viruses and infectious diseases. She joined IAVI in 2021 as the team lead of the Vector Evaluation and Quality Control Team. She coordinates efforts in the selection, production, and evaluation of preclinical vesicular stomatitis virus-based vaccine candidates for multiple programs, including Lassa fever, Marburg virus disease, Sudan Ebola virus, HIV, and SARS-CoV-2.

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Lucia Reiserova, Analytical Scientist I, Vector Design

Lucia Reiserova joined the Vaccine Vector Design and Early Development Lab Team in 2017. In her role as an analytical scientist, she is involved in developing vaccine candidates against various infectious diseases, as well as constructing, propagating, purifying, and characterizing vesicular stomatitis virus vectors, and in the production of lead vaccine candidates under controlled laboratory conditions in the Early Development Lab.

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Judy Santana, LVT, RLAT, Veterinary Technician I, Preclinical 

Judy Santana is a member of the Preclinical Team and is part of the cross-team collaboration with the Immunology Team. She is involved in the preclinical testing of IAVI’s novel vaccine designs and has been with IAVI since 2021. She also serves on the DDL’s safety committee and on IAVI’s Wellness committee. 

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Talibah Stephenson, Laboratory Coordinator 

Talibah Stephenson Joined IAVI in 2024 as the Lab Coordinator in the DDL. She works as a part of the operations team, supporting the scientists’ everyday tasks as well as coordinating procurement and instrument maintenance 

Aaron Wilson

Aaron Wilson, Analytical Scientist II, Vector Immunobiology 

Aaron Wilson joined the DDL in 2005 and is a member of the Immunobiology and Candidate Evaluation Team. In his role as a researcher, he is responsible for multiple activities such as managing and operating an advanced flow cytometry core facility, as well as laboratory data management and the application of advanced analytics and data science.  

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Xin Yao, Ph.D., Research Associate II, Vector Design

Xin Yao, Ph.D., joined the Vaccine Vector Design Team in 2024. He is responsible for multiple activities, including vector cloning, sequencing, and protein expression verification.