Viral respiratory infections (VRIs) like the common cold, viral pharyngitis, acute bronchitis, and influenza (flu) are among the most common human illnesses. Annual vaccines for flu lack acceptance and have variable efficacy. There are no vaccines for other VRIs, and the flu vaccine cannot prevent them. Conventional treatments for VRIs are generally lacking; even neuraminidase inhibitors (e.g., oseltamivir, zanamivir) are only marginally effective, with substantial adverse effects (AEs). Antibiotics do not affect viruses; nonetheless, lacking effective conventional medicines, patient demand for antibiotics continues, contributing to bacterial resistance. Many herbal medicines are used to prevent and treat VRIs. Some are backed by research; others, by traditional use; some, by both. Generally, no one herb can resolve VRIs. Multi-herb treatments tailored to the patient are most effective. Yarnell discusses a range of herbs useful for treating and/or preventing VRIs, adding his insights as a clinician.

Many herbs act directly against the viruses…