PRA Health Sciences
PRA Health Sciences

In vaccine clinical trials, time is often of the essence. There is little room for delay in enrolling patients and meeting tight timelines.

With multiple countries and regulatory agencies as well as populations that may already be well-vaccinated, much of Europe can pose feasibility challenges. To keep vaccine studies moving ahead quickly, what are some key steps to ensuring rapid enrollment in this part of the world?

Starting with the best sites -- those with a proper network and databases as well as proven success -- is essential. The next step is to engage with them early on by inquiring how many subjects each site can realistically enroll; getting this part right requires a lot of planning and risk management.

Because vaccine studies can be conducted in several or more European countries at the same time, it can be a challenge finding countries where the investigational vaccine would not interfere with regular vaccine schedules, which can vary. Finding the right countries and the right sites where a new study would not conflict with the vaccine program can make a significant difference.

Early engagement should also give each site an opportunity to review and comment on the protocol, if possible, and for appropriate suggestions to be implemented. The goal for every site, of course, is to achieve enrollment targets on time and to meet the trial’s needs and expectations.

One key enrollment strategy is to do site overreach during the Clinical Trial Application (CTA); that is, to identify back-up sites that could be opened for enrollment if needed and/or to expand country-specific enrollment targets beyond what may be anticipated at the start. This process can save time later if a site is able to enroll more patients than projected; no need to request approval from the regulatory agency – or to update the patient insurance certificate for the number of patients the insurance covers -- for those additional subjects. This step can help compensate if other sites find they are not able to meet targets.

Using Europe’s centralized regulatory submission strategy, the VHP (Voluntary Harmonization Procedure), streamlines the application process and can help achieve harmonized and quick approvals for CTAs in many EU member states. This step does not eliminate the need to submit to each country’s own regulatory agency, but after VHP approval country approvals can be obtained significantly faster.

By establishing excellent communication with sites from the beginning -- and maintaining close communication throughout enrollment -- everyone on the project can understand and engage with the common goals. Communication, and staying both involved and available at multiple levels of management, greatly contributes to success.

When the entire project team is committed to recruitment deadlines, and team members are kept up to date on enrollment figures and targets, regular reminders – plus persistence from the project management team – contribute to meeting tight timelines and making a vaccine trial in Europe a success.

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