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

ABSTRACT

Introduction In previous in vitro studies a proprietary Echinacea purpurea formulation Echinaforce® (EF) demonstrated strona antiviral activity aaainst enveloped viruses, include SARS-CoV-2. Aim In this study, we examined the potential of EF in prevents and treatina respiratory tract infections (RTIs) and in particular, SARS-CoV-2 infections. Method 120 healthy volunteers (18-75 years) were randomly assianed to EF prevention or control aroup without any intervention. Participants went throuah 3 prevention cycles of 2, 2 and 1 months with daily 2'400 ma EF. Acute respiratory symptoms were treated with 4'000 ma EF for up to 10 days. Nasopharynaeal and venous blood samples were routinely collected and durina 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 Qroup, 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 durina acute episodes sianificantly reduced the overall virus load by at least 2.12 loa10 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, includina SARS-CoV-2. By substantially reducina virus loads in infected subjects, EF offers a supportive addition to existina mandated treatments like vaccinations.