Immunogenicity and Safety of Respiratory Syncytial Virus Vaccine in Lung Transplant Recipients

Inclusion Criteria (for lung transplant recipient) : * Adults aged 19 years or older who voluntarily provide written informed consent to participate in the study * Recipients of a lung transplant who are receiving immunosuppressive therapy to prevent allograft rejection. Inclusion Criteria (for control) : * Adults aged 60 years or older who voluntarily provide written informed consent to participate in the study. * Individuals who do not have medical conditions associated with immunocompromise (e.g., malignancy, bone marrow transplantation, solid organ transplantation, HIV infection, or dialysis) and have not received ongoing chemotherapy, radiation therapy, immunosuppressive therapy, or immunomodulatory therapy within 6 months before vaccination. Exclusion Criteria: Participants will be excluded if they meet any of the following criteria * Previous receipt of any RSV vaccine. * RSV infection diagnosed within the past 12 months. * History of a severe allergic reaction to any component of the RSV vaccine. * Moderate or severe acute illness at the time of screening. * Pregnancy, planned pregnancy, or breastfeeding. * Any underlying medical condition for which intramuscular injection is contraindicated. * Any other condition that, in the investigator's judgment, may make the participant unsuitable for evaluation of immune responses.