Editorial- RSV Vaccine
Introduction
Respiratory syncytial virus (RSV) is a significant cause of morbidity and mortality in infants worldwide, with over 33 million cases of lower respiratory tract illness, 3.6 million hospitalizations, and more than 100,000 deaths each year. RSV also causes severe lower respiratory tract illness in older adults. A substantial research-and-development pipeline of prophylactic products against RSV includes vaccines and long-acting monoclonal antibodies.
RSVpreF Vaccine
RSVpreF, a bivalent vaccine containing RSV F from subtype A and B viruses, has been evaluated in older adults and infants of women who received it. The vaccine showed vaccine efficacy against RSV-associated lower respiratory tract illness, meeting both primary endpoints in older adults, and 51.3% vaccine efficacy against medically attended RSV-associated lower respiratory tract illness within 180 days after birth in infants. However, the vaccine did not prevent medically attended lower respiratory tract illness of any cause.
Safety Concerns
The vaccine's safety and side-effect profiles were acceptable, with an exception of one case of Guillain-Barré syndrome and one case of Miller-Fisher syndrome reported within a week of vaccination.
Future Research
Additional data is required regarding protection through a second RSV season, concomitant administration of other vaccines, and postmarketing evaluations to assess the incidence of serious neurologic outcomes. Policy decisions are required for offering maternal immunization with RSVpreF vaccine or a long-acting RSV monoclonal antibody in infants, and enhanced communication between obstetrical and pediatric care providers is necessary to ensure appropriate use of each product. Additional research is also required for the use of RSVpreF vaccine in low-resource settings, including its effect on lower respiratory tract illness of any cause. The development of other vaccines inducing humoral and cellular immune responses in populations that have not been previously infected with RSV is necessary for protecting older infants and children.
Conclusion
The RSVpreF vaccine has shown promising results in preventing RSV-associated lower respiratory tract illness in older adults and infants. However, additional research is required to evaluate the vaccine's safety and efficacy against severe RSV-associated lower respiratory tract illness and determine its use in low-resource settings. Critical scientific and programmatic questions remain unanswered, and substantial work is required to guide decision-making and implementation for successful prevention of RSV illness in both young and old populations.