Infections among infants and young children are common and can result in serious untoward outcomes . In particular, newborns’ increased susceptibility to infection has made improving child survival a key priority for global development efforts. To address this, the United Nations (UN) Sustainable Development Goals aim to end preventable deaths of newborns and children younger than 5-years-old by 2030, and to reduce neonatal mortality from the current rate of 19 per 1000 live births to a maximum of 12 per 1000 live births . There has been substantial progress over the past several decades, with the total number of under-five deaths reduced by more than half from 12.6 million in 1990 to 5.4 million in 2017 . Progress in protecting newborns however, has been slower. According to the World Health Organization (WHO), 2.5 million newborns died globally in 2017—a staggering 46% of deaths in children under 5 years of age, with pneumonia and sepsis/meningitis responsible for 30% of these neonatal deaths . This lack of progress led to the United Nations Inter-Agency Group for Child Mortality Estimation (UN IGME) call for expanding effective preventive interventions targeting the main causes of mortality in this vulnerable group . Each year, vaccines prevent more than 2.5 million child deaths globally . Vaccines have an expansive reach and rapid impact, while at the same time saving lives and costs, making them an attractive intervention to target pregnant women against vaccine preventable disease. Maternal immunization is a preventive strategy that provides protection to the newborn and young infant through the antenatal transfer of maternally-derived pathogen specific immunoglobulin G (IgG) antibodies via the placenta  and is considered safe for the mother and infant, as assessed by the WHO Global Advisory Committee on Vaccine Safety (GACVS) . Vaccines such as tetanus toxoid, have been recommended for pregnant women worldwide since the 1960s, and influenza vaccine, which is recommended in certain settings and risk groups. Other vaccines such as pertussis-containing vaccines have been recommended in some middle and high-income countries since 2011. In general, inactivated vaccines that are safe and available for the general population, can be offered to pregnant women when they or their fetus are at risk from exposure to a vaccine preventable disease. Furthermore, promising vaccine candidates against Respiratory Syncytial Virus (RSV) and Group B Streptococcus (GBS) are currently under development, offering the potential to reduce a substantial burden of respiratory and bloodstream infections in the neonatal period (see Chapters 10 and 11). These vaccines hold promise to protect the mother, the newborn, or both, but their benefit will only be maximized if optimally implemented. To do this there are some key issues common to all vaccines, which need to be considered. These include: knowledge of disease burden, existing delivery platforms, education, training, communication, cost effectiveness and establishing the capacity for administration, including maintaining supply and cold chain requirements and following guidance on vaccination during routine antenatal care. There are also important differences in the vaccines that can be administered during pregnancy, which also need consideration, such as timing of administration, seasonality, number of doses and proportional benefit to the mother and/or newborn. Despite existing recommendations for vaccination during pregnancy, the implementation of maternal immunization programs is often challenging. Elimination goals for maternal and neonatal tetanus as of March 2019 still have not been reached in 13 countries , and despite global policy recommendations since 2012, only 81 of all 194 WHO Member States target pregnant women in their influenza immunization policy (most recent data from 2014) . The factors that affect this decision-making, and the successful implementation of maternal immunization programs, are not fully understood. To fill this information gap in relation to influenza, the WHO engaged in the Maternal Influenza Vaccine Introduction project (2013–2016) . Results from this project confirm that introduction of maternal influenza vaccines requires not only an assessment of the evidence available on disease and economic burden, introduction costs, and vaccine safety and efficacy; but also addressing information needs of implementation planners related to the operationalization of service delivery in different country settings (Fig. 1). Based on the information needs identified during the Influenza Vaccine Introduction project , WHO subsequently initiated the Maternal Immunization and Antenatal Care Situation Analysis (MIACSA) project, which is assessing Tetanus and other existing maternal vaccine service delivery strategies in low and middle-income countries (LMICs) . Ultimately the results of this project will inform discussions on barriers, facilitators, and gaps to the use of current and additional future maternal vaccines such as GBS or RSV vaccine in low resource settings [13,14].
|Title of host publication||Maternal Immunization|
|Editors||Elke E. Leuridan, Marta C. Nunes, Christine E. Jones|
|Place of Publication||London UK|
|Number of pages||25|
|Publication status||Published - 2020|