Respiratory syncytial virus does have a vaccine; however, the cost limits the distribution to the highest income countries, and a more cost-effective preventative strategy is needed.
As the most commonly detected virus in infants under 3 months of age, respiratory syncytial virus (RSV) is a worldwide concern for children from birth to 2 years of age. However, the accurate measure of that burden is still unknown. There is a need for a safe and affordable prevention strategy. In one of the largest prospective studies to date, investigators studied the disease burden of RSV lower respiratory tract infections (LRTIs) across varied global settings.
The study, “Incidence of respiratory syncytial virus lower respiratory tract infections during the first 2 years of life: A prospective study across diverse global settings,” recently published in The Journal of Infectious Diseases, covered sites from 8 countries with particularly high incidence rates in the birth cohorts from Honduras, Bangladesh, and Argentina.
“The results of our study highlight the high burden of RSV-associated illness in infants and the urgent need for global prevention strategies targeting young children,” the investigators noted in the study. “Palivizumab, a humanized monoclonal antibody (mAb), has been shown to reduce RSV severity and RSV-associated hospitalizations when administered monthly to infants born prematurely, or with congenital heart disease and chronic lung disease. However, its administration is limited to the highest-risk subgroups of those infants, and the associated high cost further restricts its availability and use to high-income settings.”
The investigators followed 2,401 children from birth to 2 years to determine the frequency of LRTIs and hospitalizations due to RSV; of these, 206 (8.6%) children had these infections. Approximately 7 out of 100 children had an RSV-LRTI in the first 6 months of life, and more often than children older than 6 months, the youngest children had more serious symptoms and were hospitalized.
The countries’ income influenced the results as well, the investigators found. “While RSV-LRTI incidence and hospitalization rates varied among countries, they were higher in low- or middle-income countries or regions than in high-income countries. We found that approximately 1 in 3 children with RSV-LRTIs also had other viruses which could cause respiratory illness. These results show that children younger than 2 years are greatly affected by RSV, especially in low- and middle-income countries. Programs to prevent RSV infections in young children around the world would likely bring health benefits.”
The prospective, observational cohort study was conducted at study sites located in 8 countries: Argentina, Bangladesh, Canada, Finland, Honduras, South Africa, Thailand, and the United States.
“The significant burden of RSV during infancy and up to 2 years of age underscores the global imperative to prioritize the development and implementation of safe and effective RSV preventive strategies” the investigators wrote.
Of 2402 children enrolled in the study, 2401 were included in the analyses and 2148 (89.5%) completed the study. Characteristics of the children and mothers varied slightly by country. More than half (55.2%) of the mothers were between 28 and 37 years of age at delivery; 49.5% of them had higher education (university or postsecondary school).
“Our results support true regional variations in disease burden. RSV-LRTIs, severe RSV-LRTIs, and RSV hospitalizations were detected in all 8 countries, but incidence rates varied largely from one country to another. In most countries, RSV-LRTI incidence was consistently highest in infants less than 6 months of age with an observed stepwise decline among those aged 6–11 and 12–23 months.”
The present study indicates RSV disease is a global concern from 6 months up to 2 years of age, which could be addressed by infant immunization, the investigators wrote.