New Initiative Helps Researchers Enroll Healthy Volunteers In High Impact Trials

A conversation with 1Day Sooner Director of Clinical Trials Circe McDonald

Patient recruitment is tough enough, but throw in factors like a trial budget of less than $1 million, fewer than 50 participants, and feeble participant recruitment resources, and outside help can be a lifeline. This is especially true for academic researchers.

To help sponsors in dire recruitment straits, 1Day Sooner has launched its Cooperative Participant Organization (CPO) to support early-phase, high-impact infectious disease trials and controlled human infection studies. And while it aims to assist the sponsors, the CPO emphasizes the role of the patient, ensuring their involvement means that studies are designed with them, not just for them.

In this Q&A, Circe McDonald, 1Day Sooner’s director of clinical trials, talks about the CPO, the gaps it hopes to fill, and the importance of incorporating participant input. As a bonus, they’re highlighting the unique perspective of some of the CPO staff who are both trial volunteers and scientists.

Clinical Leader: Can you briefly describe the CPO and the impetus for forming it?

Circe McDonald: 1Day Sooner’s Cooperative Participant Organization (CPO) partners with study teams to meaningfully involve healthy volunteers in the design and execution of clinical trials. Our goal is to help researchers conduct studies with participants, not on them. This collaborative approach strengthens recruitment and retention, accelerates study timelines, and helps bring new therapies to patients sooner. We work knowing that every day a trial is accelerated represents lives improved or saved.

How might the CPO address the challenges academic researchers face when conducting studies under limited budgets and resources?

Academic investigators frequently design and lead only a handful of trials over their careers, often with less funding and without the dedicated clinical operations and recruitment teams from which their peers in industry and at CROs benefit. The CPO helps bridge this gap by offering both practical trial operations expertise and a deep understanding of participant experience. As a non-profit funded by philanthropic grants, we partner with high-impact academic teams at or below cost, providing tailored assistance that enhances study design, recruitment, and execution. Importantly, the CPO also strengthens the broader research ecosystem by facilitating connections among regulators, global academic networks, and philanthropic funders to align scientific innovation with participant advocacy and real-world feasibility.

You’re focusing on collaborators in Europe, North America, and Africa. Why are these regions your greatest focus? And how did you engage and ultimately select your first collaborators? What were their reasons for joining?

We began by focusing on North America and Europe, where most clinical trials are conducted, where most of our staff was located, and where several of our early partners already had established research programs. At the same time, our commitment to infectious disease research and global equity made it essential to engage collaborators in Africa, a region where innovative studies can have a disproportionate public health impact.

1Day Sooner emerged during the COVID-19 pandemic to advocate for people who participate and want to participate in high-impact medical studies, particularly human challenge trials, where healthy volunteers are infected with a disease to test a vaccine or treatment or to learn other important information. Over the past two years, our pilot collaborations have centered on study teams eager to advance vaccine and therapeutic development using controlled human infection models, particularly in hepatitis C and malaria. We selected partners with strong scientific programs that faced clear operational or engagement gaps our model could help fill.

These partnerships allowed the CPO to demonstrate how structured participant collaboration can streamline trial design, improve feasibility, and strengthen stakeholder alignment. They also built the foundation for our broader network, linking academic investigators, regulators, and philanthropic funders to support ethically robust, globally connected, and participant-informed research.

How does the CPO help incorporate study participants into the trial design process, and why is that important?

Since our founding in 2020, over 40,000 people have signed up with us, expressing interest in early-phase medical research, including human challenge studies and other vaccine trials. This network helps to bring authentic participant perspectives into trial design. Through targeted surveys, focus groups, and workshops, we identify participant priorities, such as burden of participation, trial length, acceptable risk, compensation, and other equity, and translate these insights into actionable recommendations for study teams.

Our embedded CPO staff, who combine scientific training with first-hand trial experience, work alongside investigators to refine protocols, improve participant materials, and anticipate retention challenges before studies launch. We also conduct structured debriefs with investigators and participants to capture lessons learned. By embedding participant input early in the trial life cycle, the CPO helps study teams design more feasible, ethical, and efficient trials that recruit and retain participants while improving the experience of the participants themselves.

For example, for one inpatient study, participants emphasized that continuous, reliable internet access was essential to maintain work and study commitments during their stay. In response, the study team implemented redundant internet connections, enabling participants to have confidence in their ability to continue professional and academic activities. This low-cost change significantly improved recruitment rates and retention.

In another case, a potential participant focus group expressed a preference for a study design that involved a slightly higher level of risk in exchange for a shorter overall study duration. Incorporating this feedback allowed investigators to shorten the expected study timelines by more than a year. The change both accelerated trial completion and reflected participants’ informed risk–benefit preferences.

What can we learn about the motivations of healthy volunteers you’ve engaged with the CPO?

Research on healthy participant experience, including work by 1Day Sooner, shows that most healthy volunteers are motivated to participate in clinical trials by a roughly equal mix of altruism, compensation, and curiosity about their health and medical research generally. Most are not driven by financial desperation, novelty-seeking, or risk-taking. Volunteers consistently value clear communication, trust in institutions and the study investigator, and information about both study results and their own health. While participants want their contributions to make a real impact, they are sensitive to excessive demands or perceptions of exploitation, futility, or obfuscation. Practical factors such as time commitment, ease of enrollment, and clarity of communication typically weigh more heavily in participation decisions than the risks of the studies themselves. In fact, many participants demonstrate greater risk tolerance than ethics boards often assume.

CPO members include previous trial volunteers with professional expertise in infectious diseases, volunteer engagement, data management and analysis, and early-phase clinical trial operations. How did you engage these people, and why is it important that some trial volunteers also have clinical research expertise?

The CPO intentionally recruits team members who combine firsthand experience as clinical trial participants with professional expertise in related research. Many scientists serve as healthy trial participants, driven by their significant curiosity in the area, a higher level of comfort with trial participation, and an increased awareness of ongoing clinical trials that might be recruiting. This dual background is essential for translating between the priorities of participants and the technical needs of investigators.

Having staff who can “speak both languages,” the operational and scientific factors which inform the design of clinical trials and the lived experience of participation, ensures that studies are not only scientifically robust but also ethically and logistically feasible. This integration of participant representatives parallels the integration of patient advocacy groups, an approach that has proved to strengthen trial design, improve recruitment and retention, and build trust among participants, investigators, and oversight bodies alike.

Here at 1Day Sooner, our staff has taken part. I previously worked for over six years in the pharmaceutical industry as a bioinformatician and data scientist, focusing on clinical trials for emerging viral diseases and hepatitis B. I’ve also participated as a healthy volunteer in Phase 1 vaccine trials for HIV, Ebola, and Zika.

Similarly, research lead Paul Zimmer-Harwood, Ph.D., participated in a malaria challenge trial as well as a COVID-19 challenge trial before working for 1Day Sooner and now contributes to hepatitis C vaccine research through publications, conference presentations, and economic analyses of vaccine development pipelines. He also provides scientific guidance to prospective volunteers, helping them make informed participation decisions.

When embedded within study teams, CPO staff contribute to the design and review of informed consent forms to ensure clarity and accessibility without compromising regulatory precision. They help investigators anticipate participant burdens, such as visit frequency or sample collection demands, while understanding how these constraints affect data quality and retention. In some projects, our team has supported communications with regulators, provided structured feedback on challenge model development, and co-facilitated workshops with academic and industry collaborators on ethical participant engagement in pathogen research.

About The Expert:

Circe MacDonald is 1Day Sooner’s director of clinical trials. She coordinates 1Day Sooner’s work on the hepatitis C controlled human infection model studies. Prior to joining 1Day Sooner, Circe researched neglected tropical and viral diseases first as a bench scientist and then as a bioinformatician. They hold master’s degrees in public health and computer science.