Application of LiveSpo Navax in Treatment of Acute Respiratory Disease in Children Infected With Influenza Virus

Influenza virus types A and B is the common virus that causes Acute Respiratory Tract Infections (ARTIs) with a high risk of bronchiolitis for young children and infants. Influenza-infection symptoms range from mild fever, cough, runny nose, and wheezing to severe symptoms such as fast pulse, fast breathing, and respiratory failure. In a systematic review and meta-analysis of the global burden of seasonal influenza respiratory infections in young children, they estimated that 28.000 - 111.500 children under the age of 5 die as a result of influenza infections in 2008, of which 99% of these deaths occurred in developing countries. Influenza vaccination requires annual injections, which made it difficult for young children to get effectively immunized. Moreover, antiviral nucleotide drugs including Tamiflu (oseltamivir) are unsafe for young children and are recommended only for high-risk patients. Probiotics have emerged as promising safe candidates for supportive treatment of ARTIs and reduction of antibiotic dependence in recent years. However, the use of oral administrative probiotics as functional foods is effective only for mild symptoms and not applicable for Acute RTIs (ARTIs). Here, investigators propose that direct spraying of probiotics into the nose can be a fast and effective symptomatic treatment for ARTIs.

The objective was to investigate the symptomatic treatment effects of probiotic product LiveSpo Navax, as a liquid-suspension form containing Bacillus spores of safe B. subtilis ANA4 and B. clausii ANA39 strains, in children having acute respiratory diseases caused by influenza virus, investigators evaluation of improved efficacy and reduced treatment time of LiveSpo Navax in influenza-infected children; and measurement of changes in influenza viral load, co-infectious bacterial concentrations, and major cytokine indicators in the nasopharyngeal samples before and after 2 days using LiveSpo Navax.

Methods: A randomized, blind, and controlled clinical trial is conducted. The patient's parents are required to provide the following information about their children: full name, sex, age, obstetric history, vaccination history, and antibiotic use history... After informed consent, 70 patients with ARTIs due to influenza virus will be randomized into 2 groups (n = 35/group): the control group (named "Control" group) uses 0.9% NaCl physiological saline and an experimental group (named the "Navax" group) use the probiotics LiveSpo Navax. The patient is given a coded spray in the form of a blind sample to ensure the objectivity of the study. The clinical follow-up will be 5 days, nasopharyngeal samples will be collected at day 0 and day 2 to evaluate potential reductions in viral load and co-infection bacteria, as well as modulation of overreacted cytokine release and the presence of probiotic spores in the patient's nasal mucosa.

Real-time PCR for detection of microorganism in nasopharyngeal samples: semi-quantitative assays for measuring changes in influenza viral load and co-infection bacterial concentrations is conducted by the real-time RT-PCR/PCR routine protocol which has been standardized under ISO 15189:2012 criteria and used in Vietnam National Children's Hospital. Detection of B. subtilis ANA4 and B. clausii ANA39 are also conducted by real-time PCR SYBR Green that has been standardized under ISO 17025: 2017 standard and routinely in the Key Laboratory of Enzyme and Protein Technology, VNU University of Science.

ELISA assays for cytokine levels: pro-inflammatory cytokines levels (pg/mL) including interleukin (IL-6, IL-8) and TNF-alpha are quantified using an enzyme-linked immunosorbent assay kit (ELISA) according to the manufacturer's instructions.