Date Time Research shows nasal spray that protects against COVID-19 is also effective against common cold Research into a new drug which primes the immune system in the respiratory tract and is in development for COVID-19 shows it is also effective against rhinovirus. Rhinovirus is the most common respiratory virus, the main cause of the common cold and is responsible for exacerbations of chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease. In a study recently published in the European Respiratory Journal, the drug, known as INNA-X, is shown to be effective in a pre-clinical infection model and in human airway cells.