Across 142 infectious disease Phase 3 trials authorised in 2024–2026, the EU/EEA footprint totals 2,387 site entries and 53,144 planned participants. France is the clear operational hub with 950 sites and 18,214 planned participants, while Assistance Publique Hopitaux De Paris is the leading recorded site/institution name with 43 distinct trial participations. Small molecules dominate the portfolio, appearing in 92 of 142 trials (64.8%), but vaccines carry a disproportionately large patient footprint with 17,009 planned EU/EEA participants.
The top 10 recorded site/institution names account for 230 of 2,080 identifiable site-trial participations (11.1%). Assistance Publique Hopitaux De Paris leads with 43 trial participations, equivalent to 30.3% of all 142 trials in the cohort.
The leading infectious disease Phase 3 site network is highly concentrated in French academic hospital systems: 9 of the top 10 recorded site/institution names are in France, with Hospital Universitari Vall D Hebron as the only non-French site in the top 10.
France contributes 950 of 2,387 EU/EEA sites (39.8%) and 18,214 of 53,144 planned EU/EEA participants (34.3%). The four largest site countries — France, Spain, Germany and Italy — together account for 1,684 sites (70.5%).
| Country | Sites | Site share | Patients | Trials |
|---|---|---|---|---|
| France | 950 | 39.8% | 18,214 | 66 |
| Spain | 329 | 13.8% | 4,166 | 36 |
| Germany | 213 | 8.9% | 3,470 | 35 |
| Italy | 192 | 8.0% | 3,298 | 26 |
| Poland | 110 | 4.6% | 3,336 | 16 |
| Belgium | 99 | 4.1% | 2,455 | 25 |
| Finland | 68 | 2.8% | 2,111 | 12 |
| Bulgaria | 63 | 2.6% | 884 | 9 |
| Netherlands | 48 | 2.0% | 5,551 | 17 |
| Greece | 46 | 1.9% | 661 | 8 |
France is both the site-density and patient-volume anchor. The Netherlands is operationally different: it ranks ninth by sites with 48 sites, but second by participants with 5,551 planned participants, indicating fewer but larger country-level allocations.
HIV infection is the largest site-demand cluster with 344 EU/EEA sites across 19 trials. COVID-19/SARS-CoV-2 follows with 210 sites across 12 trials, while RSV has the highest planned patient load among the leading clusters with 8,066 participants across 5 trials.
The operational market is split between chronic antiviral programs, acute hospital infection studies, and vaccine/prevention trials. HIV drives the broadest site footprint, whereas RSV and COVID-19/SARS-CoV-2 create larger patient-volume requirements per site network.
Small molecules appear in 92 of 142 trials (64.8%) and account for 1,580 EU/EEA sites (66.2%). Vaccines appear in 25 trials (17.6%) but account for 17,009 planned EU/EEA participants (32.0%), reflecting larger prevention-study populations.
Infectious disease Phase 3 remains predominantly a small-molecule and vaccine market. Vaccines require fewer trial programs than small molecules, but their population-scale prevention designs make them disproportionately important for recruitment planning and country allocation.
CROs or outsourced clinical vendors are present in 42 of 142 trials (29.6%). CRO use rises with network size: 8 of 44 trials with 1–5 EU/EEA sites use CROs (18.2%), compared with 19 of 43 trials with 21–50 sites (44.2%) and 4 of 4 trials with 51+ sites (100.0%).
The inflection point for outsourcing appears above 20 EU/EEA sites. Smaller infectious disease Phase 3 trials are often sponsor- or academic-network driven, while large multicountry prevention or antiviral trials show much heavier CRO/vendor reliance.
Hospital, clinic and healthcare-facility sponsors lead 64 of 142 trials (45.1%), narrowly ahead of pharmaceutical companies at 57 trials (40.1%). Among named CRO/vendor records, Icon Clinical Research Limited and PPD Development LP each appear in 7 trials, followed by Parexel International Corp., PPD Global Central Labs and IQVIA Limited at 6 trials each.
| Hospital/clinic/healthcare facility | 64 | 45.1% |
| Pharmaceutical company | 57 | 40.1% |
| Educational institution | 10 | 7.0% |
| Laboratory/research/testing facility | 9 | 6.3% |
| Patient organisation/association | 2 | 1.4% |
| Icon Clinical Research Limited | 7 |
| PPD Development LP | 7 |
| Parexel International Corp. | 6 |
| PPD Global Central Labs | 6 |
| IQVIA Limited | 6 |
| Syneos Health Inc. | 5 |
Infectious disease Phase 3 is not purely pharma-led: academic and healthcare systems sponsor a larger share of trials than pharmaceutical companies. For CRO targeting, the strongest commercial signal is not the overall trial count, but the subset of larger site networks where CRO presence rises above 44%.
EU/EEA refers to EU Member States plus EEA countries present in CTIS country entries. Site count refers to country-level CTIS site totals. Site/institution participation refers to a distinct recorded site or institution name appearing in a distinct trial. Planned participants refer to CTIS country-level participant allocations. CRO means contract research organisation or named outsourced clinical vendor in the sponsor section.