In this figure, the horizontal axis is labelled days and is marked from zero, which is the time of infection, up to 10 days at one-day intervals. There are three horizontal bars, labelled virus, symptoms and antibodies, and the depth of each bar corresponds to the amount of virus or antibody or the severity of symptoms respectively. Antibody production is maximal by day 5 and the virus is reduced to a very low level by day 6. Symptoms of infection disappear by day 9.