The outbreak of the new coronavirus SARS-CoV-2 (COVID-19) in China has rapidly progressed to pandemic status of global importance. The current lack of a proven anti-viral that is effective has meant the current management of severe respiratory coronaviruses remains supportive. The success achieved in treating bacterial infections is not paralleled in antivirals. The relative paucity lies in a lack of drugs that stop replication within a living cell, and that the peak rate of growth may occur prior to symptoms.

A randomised controlled trial of lopinavir/ritonavir (an antiviral treatment commonly used to treat HIV) compared to standard of care in patients with severe COVID-19 demonstrated no clinical benefit and in 13.8% treatment had to be stopped early due to adverse events . Prophylactic use of hydroxychloroquine continues worldwide both within and outside of clinical trials but concern remains with prescribing an unproven drug with well-known adverse neurological and cardiac effects .'RECOVERY' is a large United Kingdom (UK) randomised controlled trial established to test a range of potential treatments for COVID-19 in hospitalised patients, including lopinavir/ritonavir and hydroxychloroquine. Over 12,000 patients have been enrolled from 176 National Health Service (NHS) hospitals. It showed no benefit of hydroxychloroquine nor lopinavir/ritonavir in this population, and by contrast, that low-dose dexamethasone reduces the risk of death by about one-third among patients receiving ventilation and by one-fifth in those requiring oxygen alone. However, no benefit was demonstrated amongst those not requiring respiratory support. Pharmacognosy is the study of medicines derived from natural sources. Plant extracts have been widely used to treat a number of medical conditions, with some of the best-known examples including, quinine isolated from Cinchona pubescens (cinchona tree) used to treat malaria, Papaver somniferum to make morphine and Digitalis purpurea for treating atrial fibrillation. A number of plant constituents have demonstrated anti-viral activity. Hippocrates, 'Father of Medicine' referred to Elderberry as 'natures medicine chest'.

In vitro Sambucus Formosana Nakai extract showed potent antiviral activity against human coronavirus Netherlands 63 ( NL63) in terms of decreased cytopathic effect and sub-G1 arrest in coronavirus infected cells. It produces a significant reduction in viral yield, plaque formation and virus attachment. The authors conclude that like Sambucus nigra L., Sambucus FormosanaNakai might possess antiviral features against the broad spectrum of human respiratory coronaviruses . This supports the previously published data of Sambucus spp., and Sambucus nigra L. providing the antiviral properties against influenza A and B viruses and herpes simplex type 1 . In 1995 it was demonstrated a significant improvement in symptoms in 93.3% of patients treated with standardised elderberry extract within 2 days compared to within 6 days in the control arm (p\<0.001).

Complete cure occurred in 90% of those receiving the extract in 2 to 3 days . Subsequent randomised double -blind studies demonstrated no adverse events and significant improvement in clinical symptoms and higher antibody titres in those receiving Sambuci fructus .Chen at al 2014 demonstrated with in vitro testing of coronavirus Infectious Bronchitis Virus (IBV) with Sambucus.nigra a reduction in virus titres by four orders of magnitude, compromised envelopes and membrane vesicles. This virion disruption likely renders it non-infectious . Of further interest was that complete inhibition occurred when pre-treatment of virus in combination with post- infection treatment.

SARS-CoV-2 (COVID-19) is a readily transmissible virus that has a wide-ranging incubation period of 2-14 days (US Centers for Disease Control and Prevention). The symptoms are often non-specific and include fever, cough, fatigue, diarrhoea and loss of sense of taste and smell. Clinical features range from mild to severe. Varying transmission patterns and mild symptoms are of concern as they facilitate rapid spread. Pre-existing potential drug therapies are under investigation, and only started once the patient has symptoms, but do have well established side effect profiles. Prophylaxis and prevention are currently dependent on social distancing and isolating with vaccines remaining in development, potentially not for mass use in the near future.

Sambucus extract has well documented anti-viral properties and no known drug interactions were identified in the literature. Hence, Sambucus maybe well suited for limited prophylaxis or treatment of mild/ moderate COVID-19. There is clear in Vitro evidence of activity against coronavirus and in human trials of influenza. The aim of this study is to see if Sambucol® Black Elderberry Original Liquid (Sambucus nigra) at a dose of 15ml, 4 times a day, reduces the duration or severity of symptoms of COVID-19. Symptomatic patients presenting to drive through testing (i.e. non-hospitalised) who test positive and who consent will be randomised to placebo or Sambucol® and blinded to treatment allocation. Study staff/investigators responsible for assessing outcomes and data analysis will also be blinded to treatment allocation. Data will be collected to determine resolution of symptoms and the two groups compared.