Intranasal Heparin Treatment to Reduce Transmission Among Household Contacts of COVID 19 Positive Adults and Children

Multi-centre, prospective, randomised, placebo-controlled two-arm cluster randomised superiority clinical trial. Individual households with at least one person with Polymerase chain reaction assay(PCR) or Rapid Antigen test (RAT) confirmed SARS-CoV-2 infection will be randomised so that all consenting people in that household receive intranasal heparin or placebo. The rate of subsequent PCR confirmed SARS-CoV-2 infections in exposed households will be measured to determine the effect of intranasal heparin on reducing transmission to close contacts. The rate of symptom development in all participants will be used to determine effect of treatment in preventing symptomatic disease The rate of hospitalisation of all participants will be measured to determine the effect of treatment on development of severe disease. The presence of clinical neurological long COVID symptoms will be assessed at 6 and 12 months to determine the effect of treatment on long COVID. Objectives Primary • To test the efficacy of early treatment and post exposure prophylaxis to reduce transmission to household contacts on SARS-CoV-2 PCR assay by day 10. Secondary * To test the efficacy of intranasal heparin to reduce SARS-CoV-2 viral shedding: over 10 days from day of positive swab (health professional collected nasopharyngeal swab Day 3 and 5, and Day 10: self-administered anterior nasal swab swab days 1,2,3,4,5 and 10). * To test the safety of intranasal heparin for treatment of adult and children outpatients with SARS CoV-2 infection * To test whether intranasal heparin administration reduces symptomatic disease in index cases and household contacts * To test the impact of intranasal heparin on peak severity of illness. * Quantification of replication-competent virus. * To assess the impact of intranasal heparin on long COVID neurological symptoms