Other ID delivery devices are under advanced preclinical study. Solid coated microneedles have been the subject of numerous vaccination studies in mice and larger animals to administer influenza and other vaccines (see Sect. 5.2), and have been used in a Phase II clinical trial of a drug, parathyroid hormone (Cosman et al. 2009 ). Likewise, skin electroporation, in some cases in combination with microneedles, has been studied in animals for skin vaccination. As evidence for clinical feasibility, electroporation of skin for targeted delivery of chemotherapeutic agents to skin tumors is approved and used in Europe (Gehl 2008) . Tattooing is of course in widespread human use, and its application to vaccination has been studied preclinically. Other methods to increase skin permeability, such as ultrasound, chemical enhancers and heat, are also in clinical use or trials for transdermal drug delivery applications (Prausnitz and Langer 2008) , which compliment preclinical studies of their use for vaccination. Given the large number of technologies for ID vaccination under development, and the advanced clinical status of many of them, the future outlook for bringing ID vaccination into more widespread clinical practice appears encouraging. The optimal delivery method will depend on the specific application and other factors, such as immunologic response, logistical needs, and financial constraints. Recurrent Recruitment Manoeuvres Improve Lung Mechanics and Minimize Lung Injury during Mechanical Ventilation of Healthy Mice INTRODUCTION: Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. METHODS: Mice were ventilated at low tidal volume V(T) = 8 mL/kg or high tidal volume V(T) = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cmH(2)O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. RESULTS: MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. CONCLUSIONS: Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and reduce the development of pulmonary inflammation. Mechanical ventilation (MV) of mice is increasingly used in biomedical research. While the mechanisms of ventilator-induced lung injury (VILI) have been explored intensively [1] , experimental conditions required to keep physiological parameters stable in mice during ventilation for several hours are not well defined. Major reasons for this are the focus on the mechanisms of VILI and the lack of comprehensive monitoring of pulmonary and cardiovascular key parameters in most studies.