Evaluation of the efficacy of ascorbic acid in prophylaxis of induced rhinovirus 44 infection in man.

Twenty-one healthy, susceptible adult male volunteers were enrolled in a doubleblind study designed for evaluation of the prophylactic efficacy of ascorbic acid (3 g daily) in induced rhinovirus 44 infection of the upper respiratory tract. While in continuous isolation, 11 men received 1 g of ascorbic acid three times daily, and 10 men received a placebo for two weeks, after which an intranasal inoculum containing 100 TCID50 of rhinovirus 44 was administered. Each man continued to receive the same dose of medication for one week after the viral challenge. All participants subsequently developed typical illness due to rhinovirus. Similar levels of antibody in serum, nasal washings, and sputum developed in all subjects. Nasal shedding of virus and the flow of the nasal mucociliary blanket were unaffected by the ingestion of ascorbic acid. No prophylactic benefit was demonstrated from the daily ingestion of 3 g of ascorbic acid in induced rhinovirus 44 infection in man.