Vaccines

Partner with a global industry leader

During the COVID-19 pandemic the Parexel Infectious Diseases and Vaccines team had deep involvement in multiple mRNA vaccine programs – the largest study enrolling more than 23,000 subjects and successfully completing within three months. During the 2024 – 2025 influenza season, Parexel enrolled more than 70,000 participants in different Phase III influenza vaccine clinical trials.

As an award-winning CRO and recognized global industry leader in vaccines, Parexel is uniquely qualified to drive these advances forward. Parexel was named “Best Contract Research Organization” at the 17th annual Vaccine Industry Excellence (ViE) awards in 2024, which celebrate the industry’s most outstanding achievements in the global vaccine industry. Parexel was also recognized by the Society for Clinical Research in 2023 and 2024, earning the Eagle Award for outstanding leadership in advancing the clinical research profession. 

We are a trusted and inspired partner, renowned for our expertise in cutting-edge research and innovative strategies to combat infectious diseases and develop effective vaccines. Our commitment to global health is evident through our extensive experience in pathogen-driven infectious diseases studies and our ability to accelerate vaccine trials to meet program endpoints efficiently. Our proficiency spans early- and late-phase preventive and therapeutic programs, with extensive experience in feasibility and trial design with data-driven management of recruitment, enrollment, and retention. For improved site management and quality delivery, we incorporate ongoing knowledge exchange and best practices into mandatory training. AI-enabled automation through the Parexel Precision Pathway accelerates delivery of trials and programs. 

Our expertise encompasses both preventative and therapeutic vaccines across all target populations – maternal, pediatric, adolescent, and adults – each requiring a different approach. We have worked extensively on both seasonal and non-seasonal trials. This is important because, while respiratory virus infections are predictable, every year presents different strains. Further, we have a crucial understanding of the period in each region and country when populations are acutely susceptible to specific respiratory viruses.

In these trials, timeliness is paramount to capture case events on time; many protocols require 72 hours from first symptoms. We have long-term relationships with key opinion leaders and global vaccine site networks, enabling quick provision of study documents and execution of clinical site agreements. We leverage their successful strategies, speed, and commitment to quickly start enrolling patients, often comprising a large group within a short time. This requires highly specialized expertise to meet endpoints and maintain quality encompassing safety, tolerability, dose selection, immunogenicity, and inspection readiness. For data surveillance, we use CluePoints technology to ensure quality and track trends across the study and sites. 

Our multi-disciplinary team comprises dedicated infectious disease physicians and subject matter experts in biostatistics, early clinical development, feasibility, and operational strategy. Contributing their expertise are former regulators from the FDA and EMA on our staff, with localized knowledge covering 70 countries. Parexel has the largest regulatory consulting team in the industry. Together, they apply broad experience in combatting infectious diseases of many types on a global scale. 

Indications

Our work has contributed to vaccine development for COVID-19, influenza, dengue, hepatitis, herpes simplex and zoster, and respiratory syncytial virus infections (RSV); HIV/AIDS and polio infection; and many more. We also have considerable experience in antibacterial indications such as antimicrobial resistance, tuberculosis, and bacterial infections.