Brief overview There is currently insufficient evidence to recommend quercetin supplementation as a therapy for the treatment or prevention of COVID-19. Three human clinical trials with low risk of bias suggest that oral quercetin may have a beneficial effect on the incidence and duration of respiratory tract infections in certain populations; however, further research is needed. Verdict Current evidence on the efficacy of quercetin supplementation in the treatment and prevention of COVID-19 is insufficient for its clinical recommendation at this time. Quercetin exhibits both immunomodulatory and antimicrobial effects in preclinical studies; however, only three human clinical trials, each with a low risk of bias rating, were identified in this rapid review. One study reported a decrease in incidence of upper respiratory tract infections following a competitive athletic event. A larger community clinical trial reported a benefit in older, athletic adults only.

Brief overview Current evidence suggests that Echinacea supplementation may decrease the duration and severity of acute respiratory tract infections; however, no studies using Echinacea in the prevention or treatment of conditions similar to COVID-19 have been identified. Few adverse events were reported, suggesting that this herbal therapy is reasonably safe. Because Echinacea can increase immune function, there is a concern that it could worsen over-activation of the immune system in cytokine storm; however, clinical trials show that Echinacea decreases levels of immune molecules involved in cytokine storm. Verdict Echinacea supplementation may assist with the symptoms of acute respiratory infections (ARI) and the common cold, particularly when administered at the first sign of infection; however, no studies using Echinacea in the prevention or treatment of conditions similar to COVID-19 have been identified. Previous studies have reported that Echinacea may decrease the severity and/or duration of ARI when taken at the onset of symptoms. The studies reporting benefit used E. purpurea or a combination of E. purpurea and E. angustifolia containing standardized amounts of active constituents. Few adverse events from the use of Echinacea were reported, suggesting that this herbal therapy is reasonably safe. No human trials could be located reporting evidence of cytokine storm when Echinacea was used for up to 4 months. When assessing all human trials which reported changes in cytokine levels in response to Echinacea supplementation, the results were largely consistent with a decrease in the pro-inflammatory cytokines that play a role in the progression of cytokine storm and Acute Respiratory Distress Syndrome (ARDS), factors that play a significant role in the death of COVID-19 patients. While there is currently no research on the therapeutic effects of Echinacea in the management of cytokine storm, this evidence suggests that further research is warranted.

Objectives: The incidence and the prevalence of eosinophilic esophagitis (EoE) are increasing, and healthcare utilization among children with EoE is high. This study provides novel insights into the health services and the treatments, including complementary medicines (CMs), used by carers to manage their children's EoE as well as the carers' beliefs and attitudes toward these treatments. Methods: A national cross-sectional online survey was conducted in Australia between September 2018 and February 2019. The survey included questions about health service and treatment utilization, health insurance and government support, health-related quality of life of children with EoE and their carers, views and attitudes toward CM use, and perceived efficacy of treatment. Results: The survey was completed by 181 carers (96.6% of whom were mothers) of EoE children. Most children (91.2%, n = 165) had seen a medical doctor for their EoE, and almost half had consulted with a CM practitioner (40.3%, n = 73). Pharmaceuticals (n = 156, 86.2%) were the most commonly used treatment option, followed by dietary changes (n = 142, 78.5%), CM products (n = 109, 60.2%), and CM therapies (n = 42, 23.2%). Most children received care from numerous practitioners on multiple occasions, indicating a substantial financial and treatment-related burden. Conclusions: A variety of practitioners are involved in the care of children with EoE, and a high rate of CM use warrants further attention to ensure that appropriate treatment is provided. Carer involvement and guidance, combined with individual practitioner expertise, referrals, and collaboration between providers, is essential to successfully navigate this complex disease and provide adequate care for these patients.

Brief Overview Seven human clinical trials with some risk of bias suggest that multivitamins may be a safe and effective intervention to relieve some symptoms of respiratory tract infections, increase micronutrient status and immune function; however, further research is needed. There is currently insufficient evidence to recommend multivitamins as a therapy for the treatment or prevention of COVID-19. Verdict The overall quality of research examining the effect of prophylactic multivitamin supplementation on the effects of the acute respiratory tract infections (ARTI) is weak. Most of the available research included adults aged 50 years or over recruited through either the community or institutional settings (i.e. hospital facility, residential care facility). The multivitamin supplements used contained at least five vitamins and minerals and were administered between three months and two years (median: 15 months). Based on the available evidence, multivitamin supplementation does not appear to reduce the incidence of ARTI or mortality (both ARTI-related and all-cause). The effect of multivitamins taken before infection on the duration of ARTI is unclear due to conflicting results across studies. Multivitamins may, however, reduce the symptoms associated with ARTI such as headache, conjunctivitis, and activity restriction but not the overall symptom scores. No differences in health service visits, inclusive of primary and tertiary care, has been identified for individuals taking a multivitamin prior to an ARTI.

Brief overview Current evidence from published systematic reviews indicate that oral intake of vitamin C may assist with symptoms of acute viral respiratory infections (ARI) by reducing fever and chills, relieving chest pain and assist in reducing symptoms of common cold-induced asthma. Intravenous (IV) vitamin C administration may reduce the need for vasopressor support and the duration of mechanical ventilations in critically ill patients in hospital. COVID-19 has similar signs and symptoms of ARI. Further studies involving patients with COVID-19, either through administration of oral vitamin C in mild cases or IV vitamin C in critical cases, would be advantageous to examine if it is safe and efficacious. Verdict Oral vitamin C may assist with the symptoms of acute respiratory viral infections (ARI) and common cold-induced asthma but no studies have been identified justifying oral vitamin C for the prevention or treatment of coronavirus infections including COVID-19. When taken at onset of ARI, oral vitamin C may reduce the duration of symptoms including fever, chest pain, chills and bodily aches and pains. It may also reduce the incidence of hospital admission and duration of hospital stays. For individuals admitted to hospital with community-acquired pneumonia, vitamin C may improve respiratory function in more severe cases. No major adverse events nor interactions were reported by either method of administration. However, there is an absence of high quality, contemporary clinical research examining this topic. Current evidence suggests further studies are needed to better understand the value of both oral and IV vitamin C for ARI, including COVID-19.