Services
We provide comprehensive clinical research services for biotechnology and pharmaceutical companies developing preventive and therapeutic vaccines.
By combining early-phase clinical expertise with a deep understanding of EU regulatory requirements, we help sponsors generate reliable, globally accepted clinical trial data.
Convex brings CRO and clinical site services together in one integrated model, giving sponsors a single, experienced team throughout the study lifecycle. This approach simplifies operations, improves efficiency, and ensures consistent quality from study design to final reporting.
We work with both innovative biotech and established pharmaceutical vaccine programs, adapting our approach to the specific development stage and risk profile of each product.
Convex is internationally recognized for its expertise in Phase I and First-in-Human vaccine clinical trials. Early-phase vaccine studies are critical decision points, and our Phase I unit is designed to generate clear, decision-ready data while maintaining the highest safety standards.
Phase I vaccine studies conducted at Convex clinical research site focus on:
Our dedicated Phase I clinical research unit in Europe supports both inpatient and outpatient vaccine studies, enabling intensive post-vaccination monitoring and rapid medical response when required. All studies are conducted by experienced investigators, emergency medicine specialists, and highly trained study nurses with deep expertise in biologics and vaccines.
Convex supports EU vaccine clinical trials from Phase I through Phase III, combining early-phase expertise with the operational discipline required for late-stage development. Our teams provide continuity, deep institutional knowledge, and consistent quality across all stages—allowing sponsors to advance vaccine programs with confidence and control.
From Phase II dose optimization and immunogenicity confirmation to large-scale Phase III execution, Convex delivers the scientific rigor, operational oversight, and regulatory alignment needed to generate decision-ready, globally acceptable clinical data.
Convex has supported clinical development programs across a wide range of vaccine modalities, including traditional and next-generation technologies. Our teams understand that each platform carries unique safety considerations, immune response dynamics, and regulatory expectations.
We adapt study designs, safety monitoring strategies, and immunogenicity endpoints to the specific characteristics of each vaccine technology, ensuring scientifically meaningful and regulator-ready outcomes.ired. All studies are conducted by experienced investigators, emergency medicine specialists, and highly trained study nurses with deep expertise in biologics and vaccines.
Safety and immunogenicity are the cornerstones of vaccine clinical research. At Convex, both are embedded into every operational and clinical decision.
Participant safety is ensured through continuous medical oversight, real-time adverse event detection, and robust pharmacovigilance processes aligned with EU and global regulatory requirements. Our teams are trained to identify, assess, and report safety events with speed, accuracy, and transparency.
Immunogenicity assessments are performed through structured clinical and laboratory processes, supported by standardized sampling and close collaboration with qualified bioanalytical laboratory. This ensures high-quality, traceable immune response data suitable for global regulatory submissions.
Running vaccine clinical trials in Europe requires a strong understanding of local regulatory requirements and close interaction with the relevant authorities. Convex works in full compliance with the EU Clinical Trials Regulation (CTR 536/2014) and ICH-GCP E6, ensuring that all study data is suitable for EMA, FDA, and other global regulatory submissions.
Our regulatory teams support sponsors at every stage of the trial lifecycle—from initial submissions and protocol amendments to inspection readiness and post-study documentation—helping programs move forward smoothly and with confidence
At Convex, our teams work as one—clinical operations, site staff, safety, and data specialists are closely aligned throughout the study. This approach simplifies collaboration, reduces risk, and helps keep projects on track.
With CRO services and clinical site execution under one roof, sponsors benefit from a higher level of visibility, control, and predictability, especially in complex vaccine trials
When biotechnology and pharmaceutical sponsors consider where to conduct a vaccine clinical trial in Europe, they are not simply choosing a country. They are selecting a regulatory environment, a clinical research culture, medical expertise, access to study participants, and a way of working.
Over time, Bulgaria has steadily established itself as one of the most attractive locations within the European Union for vaccine clinical trials, particularly for Phase I–III studies. This is not driven by “low cost,” but by a balanced combination of EU regulatory certainty, high-quality clinical execution, operational efficiency, and predictability.
Full Alignment with the European Union Regulatory Framework
One of Bulgaria’s strongest advantages is its status as a full member of the European Union. As a result, all clinical trials—including vaccine studies—are conducted under the same regulatory standards that apply in Germany, France, the Netherlands, and other leading EU countries.
Vaccine clinical trials in Bulgaria are conducted in full compliance with:
Clinical data generated in Bulgaria is fully acceptable to the EMA and is routinely used for FDA and other global regulatory submissions. For sponsors, this provides confidence and peace of mind—there is no need for additional validation, repeat studies, or regulatory compromises.
A Long-Standing Track Record in Clinical Research
Bulgaria is not new to clinical research. The country has more than 40 years of experience conducting international clinical trials across a wide range of therapeutic areas, including infectious diseases and vaccines.
Many physicians and principal investigators in Bulgaria have participated in dozens of international clinical trials by working regularly with global sponsors and CROs and in the same time have a strong understanding of EMA and FDA expectations. This depth of experience has created a well-established clinical research culture focused on protocol discipline, patient safety, and data quality—key elements for successful vaccine development.
Highly Qualified Medical Professionals and Clear Communication
Bulgarian Clinical study investigators, study nurses, and clinical research teams are highly trained and well prepared. Medical education meets EU standards, and many professionals have additional international training or experience in global research collaborations.
Another important advantage is the high level of communication in English. It is clear and efficient. Documentation is maintained accurately and professionally. Also the risk of misunderstandings or delays is minimized. For international sponsors, this significantly improves day-to-day collaboration and overall study efficiency.
Faster Study Start-Up Without Compromising Quality
Vaccine development programs are often time-sensitive. Bulgaria offers efficient and predictable timelines for: ethics committee approvals/ regulatory submissions and study initiation
Importantly, this efficiency does not come at the expense of quality or oversight. Bulgarian regulatory authorities and ethics committees are known for their balanced and professional approach, ensuring patient protection and scientific integrity while avoiding unnecessary administrative burden.
For sponsors, this translates into earlier study start-up and smoother execution, without regulatory surprises later in the program.
Strong Access to Healthy Volunteers and Patient Populations
The success of vaccine clinical trials depends heavily on reliable recruitment and retention.
Bulgaria offers several key advantages:
For Phase I vaccine studies, Bulgaria benefits from well-organized databases of healthy volunteers. For Phase II–III trials, sponsors have access to diverse and representative patient populations.
All recruitment activities are conducted ethically, transparently, and in full compliance with EU regulations and informed consent requirements.
Cost Efficiency with High Scientific Value
While cost should never be the primary driver of clinical research decisions, Bulgaria offers an excellent cost-to-quality ratio.
This allows sponsors to optimize development budgets. In practical terms, sponsors can often achieve greater scientific value with the same budget, without compromising regulatory or ethical standards.
An Excellent Environment for Phase I and First-in-Human Vaccine Studies
Bulgaria has become an increasingly attractive location for Phase I and First-in-Human (FIH) vaccine trials, supported by:
Together, these factors provide a controlled, safe, and professional environment for early-stage vaccine development, including novel and next-generation platforms.
Strong Focus on Data Quality and Data Integrity
Clinical research centers in Bulgaria are accustomed to working under: sponsor audits, CRO audits and regulatory inspections
Seamless Integration into Global Clinical Development Programs
Clinical trials conducted in Bulgaria integrate smoothly into global development strategies. Data generated locally can be pooled with data from Western Europe or the United States without regulatory concerns.
This makes Bulgaria a flexible option for EU-only vaccine trials and global multi-country development programs
A Collaborative and Practical Working Style
Many sponsors highlight the pragmatic and partnership-oriented approach of Bulgarian clinical research teams. Communication is open, challenges are addressed early, and the focus remains on finding practical solutions.This collaborative working style is particularly valuable in complex vaccine programs, where close coordination and rapid decision-making are essential.
As a member of the European Union, Bulgaria offers political and regulatory stability, which is especially important for long-term clinical programs, including post-authorization and lifecycle management studies.
Sponsors can plan with confidence, knowing that the regulatory environment will remain aligned with EU standards throughout the duration of the program.
From early discovery programs to post-authorization commitments, Convex acts as a trusted long-term partner for vaccine developers. We support sponsors with scientific insight, regulatory confidence, and operational excellence—helping transform innovative vaccine concepts into approved, real-world solutions.
