Across 101 European CTIS-authorised vaccine phase 1 - 3 trials, 28 trials used at least one CRO or CRO-like outsourced operating partner, equal to 27.7% of the cohort. CRO use concentrates in larger execution models: 16 of 19 trials with 4+ countries used CROs, 14 of 22 trials with 20+ sites used CROs, and 5 of 7 trials with 1,000+ participants used CROs. ICON/PRA was the most active named provider with 9 supported trials, followed by PPD / Thermo Fisher Scientific with 8 and IQVIA with 6.
ICON/PRA supported 9 of 28 CRO-supported vaccine trials, equal to 32.1% of CRO-supported trials. PPD / Thermo Fisher Scientific supported 8 of 28 trials, IQVIA supported 6 of 28, and Almac supported 4 of 28.
The most active CROs are global operational providers rather than vaccine-only specialists. ICON/PRA, PPD / Thermo Fisher Scientific, and IQVIA together appeared in 23 trial-provider relationships across the 28 CRO-supported trials, indicating that sponsors mainly outsource execution scale, country operations, and specialist infrastructure rather than only therapeutic expertise.
CRO demand rises sharply with operating scale. CRO-supported trials averaged 5.1 countries, 32.1 sites, and 810.1 participants, compared with 1.4 countries, 8.2 sites, and 203.5 participants for trials without CROs.
| Capacity level | CRO-supported | Share |
|---|---|---|
| 4+ countries | 16 / 19 | 84.2% |
| 1,000+ participants | 5 / 7 | 71.4% |
| 20+ sites | 14 / 22 | 63.6% |
| 2 - 3 countries | 9 / 21 | 42.9% |
| 1 country | 3 / 61 | 4.9% |
The clearest CRO trigger is multi-country CTIS execution. Once vaccine trials expand beyond three European countries, CRO use becomes the dominant model. Single-country vaccine trials are mostly sponsor- or institution-run, with only 3 of 61 using CROs.
CRO support is concentrated in later-stage vaccine development. Phase 3 trials had the highest absolute CRO use, with 16 of 37 phase 3 trials supported by CROs, equal to 43.2%. Pure phase 1 trials had 0 of 23 CRO-supported trials.
Vaccine CRO demand appears to be driven less by early safety work and more by late-stage operational load: site networks, country coordination, paediatric recruitment, safety reporting, clinical supplies, and EU/CTIS submission execution.
Infectious disease had the largest absolute CRO need, with 18 of 52 infectious disease vaccine trials using CROs. By grouped disease, RSV had the largest absolute CRO-supported footprint with 5 of 10 trials using CROs, while group B streptococcus and influenza each had 3 CRO-supported trials.
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