PROJECT SUMMARY/ABSTRACT In 2019, there were 2.4 million newborn deaths, most of which are preventable. At 36 per 1000 live births, Nigeria has one of the highest neonatal mortality rates in the world. The top two causes of neonatal mortality are intrapartum asphyxia or failure to breathe at birth and prematurity. Neonatal resuscitation training reduces asphyxia-related newborn mortality and morbidity and simple interventions such as warmth, warmth, hand washing, early and exclusive breastfeeding, umbilical cord care, eye care, vitamin K administration, and immunization decrease neonatal mortality. However, initial gains in health care worker knowledge and skills rapidly decay, sometimes in a matter of weeks after training. In-person refresher training and low-dose, high frequency (LDHF) practice using manikins are proven educational approaches, but require facility space, equipment and supervision, that are often unavailable in LMICs due to lack of infrastructure, staff shortages and high rates of staff turnover. On the other hand, the high penetration of mobile smartphones and cellular network connectivity in LMICs make innovative mobile virtual simulation training feasible in LMICs. Virtual simulations can be engaged at the learner?s convenience, on their own smartphone, with game-based automated feedback that is ideal for episodic learning. Virtual simulation refresher training provides an opportunity to support the retention of essential newborn care knowledge and skills over time and to encourage migration of these skills into actual clinical practice. We propose to use mobile virtual simulations to provide accessible, standardized refresher training. Our hypotheses are that virtual simulations will provide acceptable, effective refresher training; support the retention of newborn resuscitation and care knowledge and skills among healthcare workers in LMICs; and reduce neonatal mortality. To test these hypotheses we will: 1) Develop and evaluate the usability, feasibility, acceptability and educational efficacy of Virtual Essential Newborn Care (vENC) mobile virtual simulations on essential newborn care in healthcare workers who care for newborns in community and facility-based settings; 2) Conduct a stepped wedge cluster randomized controlled trial of vENC for refresher training vs. standard practice. This will evaluate the impact of vENC refresher training on 7-day neonatal mortality rates at participating healthcare facilities. We will also measure the impact of vENC training on neonatal care knowledge and skills in healthcare workers who provide newborn care in community and facility-based settings. In addition, we will work with our partner, Microsoft to strengthen local capacity for advanced mobile technologies and research in Nigeria. If proven effective, the vENC mobile simulations could provide an accessible tool to reduce newborn mortality and morbidity and support the delivery of essential newborn care in LMICs.