A prospective observational study was performed in 75 patients with typical symptoms of COVID-19 who tested positive to IgM/IgG rapid test. Patients were isolated and treated at home using remote systems, reviewed twice a day for 10 days, and followed up to 1 month. A liposomal bovine lactoferrin (LLF) nutritional syrup food supplement (32 mg of LF/10 ml plus 12 mg of vitamin C) was administered orally in 4 to 6 doses per day for 10 days. In addition, a zinc solution was administered at the dose of 10 mg/10 ml twice or three times a day. A control group of 12 patients who took only LLF was included. All family members in contact with patients (256 persons) were also treated with half of this dose. The treatment allowed a complete and fast recovery in all patients (100%) within the first 4-5 days. Same treatment at lower dose prevented the disease in healthy persons directly related with the affected patients. Weakness (95%) followed by a dysfunction in the perception of smelling and tasting (88%), cough (83%), muscular pain (67%) were the most frequent complains. LF possess antiviral, immunomodulatory and anti-inflammatory effects which might be important for the treatment of COVID-19 infection. We conclude that LLF potentially prevent and cure COVID 19 infection.