While I was at acupuncture today my acupuncturist told me about an iodine nasal spray that supposedly helps to block viral infections. Most infections are transmitted through the nose. I'd heard of nasal vaccines before, but hadn't heard of an iodine spray. It's Povidone Iodine Nasal Spray and available at some drug stores or online from epothex.com. It's preventative, not therapeutic.