Echinacea purpurea for the long-term prevention of viral respiratory tract infections during COVID-19 pandemic: A randomized, open, controlled clinical study

Introduction In previous in vitro studies a proprietary Echinacea purpurea formulation Echinaforce^®​ (EF) demonstrated strong antiviral activity against enveloped viruses, including SARS-CoV-2.

Aim In this study, we examined the potential of EF in preventing and treating respiratory tract infections (RTIs) and in particular, SARS-CoV-2 infections.

Method 120 healthy volunteers (18–75 years) were randomly assigned to EF prevention or control group without any intervention. Participants went through 3 prevention cycles of 2, 2 and 1 months with daily 2’400 mg EF. Acute respiratory symptoms were treated with 4’000 mg EF for up to 10 days. Nasopharyngeal and venous blood samples were routinely collected and during acute illnesses for detection and identification of respiratory viruses.

Results Summarized over all phases of prevention, 21 and 29 samples tested positive for any virus in the EF and control group, of which 5 and 14 samples tested SARS-CoV-2 positive (RR=0.37, p=0.03). 11 and 20 samples indicated presence of enveloped viruses, of which 10 and 20 were Coronaviruses (p=0.046). EF treatment when applied during acute episodes significantly reduced the overall virus load by at least 2.12 log10 or approx. 99% (p<0.05), the time to virus clearance by 8.0 days for all viruses (p=0.02) and by 4.8 days for SARS-CoV-2 (p>0.05) in comparison to control.

Conclusion EF exhibited antiviral effects and reduced the risk of viral RTIs, including SARS-CoV-2. By substantially reducing virus loads in infected subjects, EF offers a supportive addition to existing mandated treatments like vaccinations.

Publication History

Article published online:
13 June 2022