Perfluoroalkyl substances (PFAS) are a diverse group of highly stable synthetic chemicals that have been extensively used since the 1960s and can be found almost everywhere in the environment. According to recent studies, PFAS concentration in blood is estimated at 95-100% of the U.S. population, due to their widespread occurrence and long half-lives in the human body. Biomonitoring studies from other countries have also underscored that PFAS is a global health concern.1,2 One of the communities facing higher risks from PFAS in their drinking water is Pittsboro, NC. PFAS levels measured in both the blood and drinking water of Pittsboro were found to be 2 to 4 times higher than those in the general U.S. population.3 Human exposure to PFAS has been linked to various adverse health effects, including immune system dysfunction, endocrine disruption, kidney toxicity, pregnancy-related hypertension, and reduced fertility.4 Environmental PFAS exposure to PFAS is linked to various long-term health issues, but there is a gap in literature on the effects of exposure to emerging PFAS chemicals like PFBS, PFHxS, GenX, or mixtures of PFAS, particularly regarding their immunotoxicity during early life, including pregnancy and breastfeeding. Therefore, this study aims to investigate maternal PFAS exposure and its effects on the immune response to (Tdap) vaccine (tetanus, diphtheria, pertussis) and placental transfer of IgG (Immunoglobulin G) to fetal compartment. Using animal models, to established causal relationship between environmental PFAS exposure and vaccine effectiveness and potential adverse health outcomes that may take years to manifest at the population level.