Efficacy and Advantages of Nasopharyngeal and Oropharyngeal Treatments for Early Intervention and Prophylaxis in Respiratory Viral Infections: A Systematic Review and Meta-Analysis (2025)
Abstract: Nasopharyngeal and oropharyngeal (NP/OP) treatments targeting the upper respiratory tract demonstrate significant efficacy in reducing the risk of progression and transmission of respiratory viral infections, including SARS-CoV-2. This systematic review synthesizes data from 66 clinical studies and multiple meta-analyses, evaluating compounds such as povidone-iodine, iota-carrageenan, nitric oxide, and others with established safety profiles. Early treatment or prophylaxis yields a lower risk profile, with efficacy rates of 38% [25-49%] for oral application, 56% [48-63%] for nasal application, and 91% [74-97%] for combined nasal and oral administration. Targeted delivery to the primary site of infection offers direct action, rapid onset, higher local drug concentrations, and reduced systemic side effects. Despite regulatory challenges, evidence supports the potential of NP/OP treatments as safe, cost-effective interventions, with polytherapy enhancing efficacy (68% [57-77%] r...