Proper treatment and early diagnosis of primary immunodeficiencies is a worldwide public heath priority and therefore the tenth volume of Pharmaceuticals Policy and Law: Focus on Immunodeficiencies focuses on awareness about this issue for the sake of many patients in need. Primary immunodeficiencies in particular are a major public health issue and are still nowadays too often ignored. However, ignoring them is an extremely costly way to handle the issue. Not treating these patients can be an additional burden to the economy or just result in poverty and increased ill-health. Unfortunately, because symptoms of primary immunodeficiencies often manifest as common affections such as pneumonia, bronchitis, or gastroenteritis, without proper knowledge about what causes these symptoms, many doctors focus on treating the symptoms rather than the cause. This leads to a huge waste of healthcare resources as the infections keep coming back and costly and prolonged hospital stays are needed. Proper treatment through immunoglobulin replacement therapy has been shown to significantly reduce episodes of infection, hospital stays and enable affected people to lead normal active professional lives. In order to put an end to this tendency, this volume strives to facilitate the increase of awareness of the issue.