COLDPREV – A randomized, double-blind, placebo-controlled inoculation study

COLDPREV – A Randomized, Double-Blind, Placebo-Controlled Pilot Clinical Study on ColdZyme® Mouth Spray against Rhinovirus-Induced Common Cold.OJRD, 2017, 7, 125–135.

COLDPREV is a double-blind, placebo-controlled study of healthy volunteers who were inoculated (infected) with a cold virus. The results show a reduction of viral load (by over 99%), as well as a reduction in the number of days with common cold symptoms by over half (54%). Both results are statistically significant compared with placebo.


Primary endpoint:

Reduction in viral load in the upper respiratory tract

Outcome measure:

Total oropharyngeal viral load for day 3-10


The viral load in the ColdZyme group is reduced with more than -99% compared with placebo (p =0,023)

  • Sneezing
  • Rhinorrhoea
  • Nasal obstruction
  • Sore/scratchy throat
  • Cough
  • Headache
  • Malaise
  • Hoarseness
  • Chilliness

The severity of each symptom is rated on a 5-grade scale as:
  • 0: “absent”
  • 1: “mild”
  • 2: “moderate”
  • 3: “severe”
  • 4: “very severe”