The only useful ways to reduce the spread of cold viruses are physical and engineering measures such as using correct hand washing technique and face masks; in the healthcare environment, gowns and disposable gloves are also used. Droplet precautions cannot reliably protect against inhalation of common-cold-laden aerosols. Instead, airborne precautions such as respirators, ventilation, and HEPA/high MERV filters, are likely the only reliable protection against cold-laden aerosols. Isolation or quarantine is not used as the disease is so widespread and symptoms are non-specific. There is no vaccine to protect against the common cold. Vaccination has proven difficult as there are many viruses involved and they mutate rapidly. Creation of a broadly effective vaccine is, therefore, highly improbable.