Far too many newborns continue to die in early life, particularly in low-and middle income countries (LMIC). Many die from infections, some of which could be prevented. During the late stages of pregnancy, antibody is transferred across the placenta from mother to child, providing protection to the infant in the early weeks of life. However, if the mother has insufficient protection against certain infections, the infant will also not be protected. Vaccinating women in pregnancy can enhance the level of antibody in the mother, thereby protecting the mother, and increasing the amount of antibody transferred across the placenta - protecting the infant from birth too. This concept has already been successfully established for the prevention of tetanus, influenza and pertussis (whooping cough). Many investigators and stakeholders are interested in using this strategy to protect infants from other serious infections, for example group B streptococcus or respiratory syncytial virus (RSV), and vaccines against these infections are in development. Some fundamental gaps in our understanding remain about the immune response to vaccines in pregnancy and in newborn infants which are essential for us to address in order to accelerate development of new vaccines. It is also very important that the scientific community tackles how best to implement such vaccine programmes in both high-income countries and LMIC. Our unique inter-disciplinary network represents stakeholders from basic science, immunology, vaccinology, social sciences, industry, public health and national and international policy makers who have come together in order to tackle the key challenges in the best use of vaccines in pregnancy and in newborns, and in the long term, improve maternal and newborn health. Specifically, the IMPRINT network is implementing collaborative research projects to answer fundamental biological questions about antibody transfer of antibody across the placenta, how to induce the "best" antibody, and its effect on the maturing newborn immune system. We are investigating if maternal vaccines could potentially interfere with the way in which the baby responds to vaccines later in infancy and childhood, to ensure that protection is not compromised at any stage. Co-factors such as nutrition or other infections might also change the way in which mothers and infants are protected by vaccines. Hence we need to take them into consideration if we are to ensure optimal protection of vaccines in pregnancy and early life. We are also finding out why women decide to receive or not to accept vaccines in different countries in order to optimise the uptake of current and new vaccines. We will endeavour to work out how vaccine safety and effectiveness can be best monitored, given the different health care systems in different countries. Addressing these implementation challenges will enable us to better understand the issues and site-preparedness in the many geographical areas and populations in which IMPRINT investigators already work. IMPRINT is a multi-disciplinary network linking investigators in Europe, Africa and Asia and can therefore address these questions comprehensively. We are uniquely set up to investigate these challenges through the diversity of expertise, availability of samples and datasets already available through our collaboration, which the members are happy to share. Through our network, we are training researchers in LMIC to take forward these important questions, and we will be the forum to provide the best evidence for the safe and efficient use of vaccines in pregnancy and newborns for the ultimate goal of lowering maternal and newborn deaths from infections.