Continued Progress in the Development of Safe and Effective RSV Immunizations

This editorial reviews pivotal progress in RSV vaccine development, culminating in 2023 with approval of two vaccines for older adults (one also approved for pregnant persons) and nirsevimab monoclonal antibody for infants. These achievements follow six decades of setbacks, including the failure of the formalin-inactivated RSV vaccine. Success hinged on identifying the prefusion F glycoprotein as a stabilized antigen. The featured Wilson et al. trial reports 83.7% efficacy against lower respiratory tract RSV disease with ≥2 symptoms and 82.4% efficacy with ≥3 symptoms. Reactogenicity was higher among vaccine recipients but serious adverse events were comparable to placebo. Efficacy against RSV subtype B was lower. The mRNA vaccine platform draws from RSV research and underpinned rapid Covid-19 vaccine development, highlighting its potential for future pandemics. The trial enrolled participants from 22 countries, but the population skewed toward "fit" older adults, limiting generalizability. Global RSV disease burden remains highest in infants in low- and middle-income countries. Current access to RSV immunizations favors high-income nations, though efforts (e.g. Gates Foundation) aim to expand availability. Phase 1 trials for pregnant persons and children are ongoing. Authors advocate for durable immunity studies, boosting strategies, and wider clinical trial inclusion.

This editorial reviews pivotal progress in RSV vaccine development, culminating in 2023 with approval of two vaccines for older adults (one also approved for pregnant persons) and nirsevimab monoclonal antibody for infants. These achievements follow six decades of setbacks, including the failure of the formalin-inactivated RSV vaccine. Success hinged on identifying the prefusion F glycoprotein as a stabilized antigen. The featured Wilson et al. trial reports 83.7% efficacy against lower respiratory tract RSV disease with ≥2 symptoms and 82.4% efficacy with ≥3 symptoms. Reactogenicity was higher among vaccine recipients but serious adverse events were comparable to placebo. Efficacy against RSV subtype B was lower. The mRNA vaccine platform draws from RSV research and underpinned rapid Covid-19 vaccine development, highlighting its potential for future pandemics. The trial enrolled participants from 22 countries, but the population skewed toward "fit" older adults, limiting generalizability. Global RSV disease burden remains highest in infants in low- and middle-income countries. Current access to RSV immunizations favors high-income nations, though efforts (e.g. Gates Foundation) aim to expand availability. Phase 1 trials for pregnant persons and children are ongoing. Authors advocate for durable immunity studies, boosting strategies, and wider clinical trial inclusion.