There is no cure for cold or flu, most people recover in about within two weeks. Paracetamol may be used to reduce aches or treat fever, headache, or body aches. Antiviral solutions ranging from simple universal saline solutions to novel compounds have been proposed to provide a temporary barrier to prevent viral infection and propagation.

The nasal spray "Humer Stop Virus" is indicated in patients presented with early symptoms of viral respiratory infection. This spray forms a protective barrier in the nasal mucosa which is the main entry of the upper air respiratory system viruses. The spray traps the viruses and helps the organism to eliminate them before they multiply themselves.

This clinical investigation is conducted to assess the performance, clinical benefit and safety of this nasal spray in patients with early symptoms of acute respiratory disease whether or not infection is related to common cold, flu or COVID virus. Indeed, presence of early symptoms of acute respiratory infection does not always imply viral infectionAntigen self-tests are available to confirm viral infection with flu viruses or severe acute respiratory syndrome (SARS-CoV-2). However, influenza and other winter viruses are not systematically searched for in general population, because this is of neither collective nor individual interest. To be as pragmatic as possible, we chose to assess performance and safety of the nasal spray on intended users in real conditions. Patients with early symptoms of cold, flu or COVID, are enrolled regardless their PCR test positivity confirming viral infection at the time of enrollment. For study needs, the primary endpoint, which aims to assess the performance of the nasal spray in terms of stopping the viral infection, is assessed in a subgroup of patients with a positive PCR test with flu, COVID or common cold virus in the nasal sample collected at enrollment.

Patients are recruited at the study site by the principal investigator, who gives a brief presentation of the study. Eligible, informed patients who sign a consent form are included and randomized.

All patients undergo three nasal swabs: at the time of enrolment, then 24 hours and 84 hours later, and complete a daily questionnaire on a secure mobile application dedicated to patient reported outcomes to assess their symptoms and provide information on any analgesic or antipyretic medication they may have been taking.

Patients randomized to the intervention group are asked to use the nasal spray as recommended and to report any difficulties with the device.

A final visit is organized on day 8 at the investigation center under the supervision of the investigator.

Inclusion Criteria:

• With early symptoms of respiratory infection (onset less than 48 hours before inclusion) of mild to moderate intensity (TSS ≥ 2 and < 9).
• Having a mobile phone allowing using the patient reported outcome App. (NursTrial®).
• Patient able to understand and comply with protocol requirements and instructions, including answering a questionnaire on a mobile phone, as required by protocol.
• Signed informed consent.
• Affiliated to a French Health insurance scheme.

Exclusion Criteria:

• Concomitant disease or infection that could interfere with participation in the study: acute ear, nose, and throat and respiratory tract disease other than the common cold, flu or COVID (e.g., tonsillitis, otitis, bronchitis) and chronic sinusitis or allergic rhinitis, or other reasons for nasal obstruction and other past or present conditions and treatments that could influence symptom scores.
• Severe nasal septum deviation or other conditions that could cause nasal obstruction such as the presence of nasal polyps.
• Known or suspected intolerance or hypersensitivity, including history of allergies, to any component investigational device material, any history of drug hypersensitivity.
• Concomitant treatment that might impair the trial results (i.e., decongestants, local anesthetics, topical corticosteroids, saline solution) during the seven days prior to inclusion.
• Smokers.
• Have a condition or is taking a medication that the Investigator and/or designee believes could jeopardize the safety of the subject, would interfere with the evaluation, or confound the interpretation of the study results.
• Non-compliant or may not respect the constraints imposed by the protocol.
• Enrolled in another clinical trial or being in a period of exclusion from a previous clinical trial;
• Woman of childbearing age (except menopausal, hysterectomised, sterilized) not using effective contraception (oral contraceptives, intra-uterine device, contraceptive implant, or condoms).
• Person belonging to a population referred to in articles 64 (incapacitated subjects), 65 (minors), 66 (pregnant or breastfeeding women), 67 (persons performing mandatory military service, persons deprived of liberty, persons who, due to a judicial decision) and 68 (patients in emergency) of the Medical Device Regulation.

Blinded assessment of viral load analyses