While impressive and clearly sufficient to warrant further research, the findings for CVT-E002/COLD-fX noted above may be viewed as tentative and incomplete by some medical authorities. This is due not only to a longstanding and perhaps misguided suspicion of herbal therapies, but to several valid scientific concerns regarding these therapies. One concern is the long history of herbal interventions initially supported by positive evidence, and later proved ineffective or minimally effective. Following this rationale, most physicians and health scientists require at least 2 independent high quality RCTs before evidence is deemed sufficient to justify recommending an herbal preparation to patients. The benchmark for accepting natural, chemically-complex therapies appears to be rising as the sophistication of evidence-based medicine increases.
All of the CVT-E002/COLD-fX trials described above are manufacturer-sponsored. Although methodology and outcomes are in general portrayed according to accepted scientific standards, these reports do tend to highlight positive findings rather than limitations. It should also be noted that several of the studies mentioned have not been published, and may be revised when subjected to the peer-review process. Finally, aside from the Predy trial,16 none of the studies cited here can be considered confirmatory Phase 3 trials. Even the Predy trial is limited by sample size and drop-out rate, as well as by lack of identification of specific viruses involved. Hence, while intriguing and promising, further development and corroboration may be required by some health organizations before the evidence on CVT-E002 could be interpreted as sufficiently robust for incorporation into health policy and practice.