There is no data available to determine whether the etiologies of pneumonia are dependent on a child´s zinc status. In general, bronchiolitis and upper respiratory tract infections are likely to be viral, whereas most cases of severe pneumonia and pneumonia-related deaths are more likely to be bacterial [1]. Recently, one in vitro study found that zinc mediates antiviral activity on respiratory syncytial virus (RSV), an etiological agent of pneumonia in children, by altering the ability of the cell to support RSV replication [11]. If zinc status has an influence on the etiology of pneumonia, this suggests that zinc deficiency might be associated with a "selective acquired immunodeficiency".