Abstract Respiratory syncytial virus (RSV) infection in adults has been reported to impose a disease burden comparable to that of influenza. Although often mild, it can cause severe disease or exacerbate underlying conditions such as asthma, particularly in elderly patients. With the increasing use of real-time PCR testing, the clinical significance of RSV infection in adults has become better recognized. Arexvy, an adjuvanted RSV vaccine, has demonstrated efficacy in preventing RSV-associated lower respiratory tract disease. We report an 82-year-old woman with uncontrolled asthma who experienced several exacerbations annually despite appropriate therapy at another hospital. In July of year X-1, she was admitted to our hospital for an asthma exacerbation requiring intensive care. After discharge, she continued long-term management at our outpatient clinic with high-dose ICS/LABA/LAMA and a leukotriene receptor antagonist, and dupilumab was added in September. Although her asthma remained relatively stable until early year X, she experienced frequent infection-triggered exacerbations from late March, including one hospitalization in April and repeated systemic corticosteroid use until late May. In June, she received the RSV vaccine Arexvy. No significant changes in type 2 inflammation markers or pulmonary function were observed before and after vaccination. However, despite mild cold symptoms in December, she did not experience any exacerbations requiring systemic corticosteroids. Her Asthma Control Test (ACT) score improved from 17 in May to 24 in October, and the annual exacerbation frequency markedly decreased from three to four times per year to none, indicating excellent control. In severe asthma, dendritic cell interferon (IFN) responses to viral infection are known to be impaired, leading to increased vulnerability to virus-induced exacerbations. Arexvy consists of a recombinant RSV prefusion F protein antigen (PreF3) and the AS01E adjuvant system, composed of monophosphoryl lipid A (MPL) and QS-21. These components act synergistically to activate macrophages and dendritic cells, inducing cytokine cascades and promoting IFN production. Therefore, in addition to preventing RSV infection, Arexvy may have enhanced innate antiviral immunity through IFN-mediated pathways, contributing to improved asthma control. This case suggests that adjuvanted RSV vaccination might offer potential benefits beyond infection prevention in elderly patients with severe asthma, warranting further investigation into its immunomodulatory effects and clinical relevance. This abstract is funded by: None
Tanaka et al. (Fri,) studied this question.