Proper hand hygiene is thought to reduce community transmission of some viral infections including rhinoviruses and RSV [10] , but the specific effect of hand hygiene on influenza has not been quantified. Again there are few apparent risks of proper hand hygiene, perhaps the greatest being the detrimental effects on skin of frequent hand washing, particularly with alcohol-based products although most of these contain emollients to buffer against excessive drying. To try to mitigate these effects as much as possible we will only supply an alcohol-based hand cleanser which includes emollients, and encourage study participants to be wary of skin irritation. The other very rare potential adverse consequence, as with all topical applications, is allergic reaction. We will use a hypoallergenic product and exclude participants who have a known allergy to alcohol or additive components of the alcohol handrub deployed.