Impact of breastfeeding on the incidence and severity of respiratory syncytial virus (RSV)-associated acute lower respiratory infections in infants: a systematic review highlighting the global relevance of primary prevention

Abstract

BackgroundRespiratory syncytial virus (RSV) is the principal cause of acute lower respiratory infections (ALRI) among infants worldwide, and an important cause of morbidity, hospitalisation and mortality. While infants are universally exposed to RSV, most mortality occurs among normal term infants from low-income and middle-income countries. Breastfeeding has been suggested to have a protective effect against RSV infection. This study aims to determine the association of breastfeeding on the frequency and severity of RSV-associated ALRI among infants.MethodsA systematic review was conducted using keywords and Medical Subject Headings on MEDLINE, PubMed, Google Scholar, EMBASE, MedRxiv and Cochrane Central Register of Controlled Trials. Full-text articles published in English from 2000 to 2021 that studied exclusively or partially breastfed infants who developed RSV-associated ALRI <12 months of age were included. Covidence software-based evidence extraction and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines were followed. Quality of evidence was analysed using UK National Service Framework grading and the risk-of-bias assessment using Robvis.ResultsAmong 1368 studies screened, 217 qualified full-text review and 198 were excluded based on pre-agreed criteria. Nineteen articles published from 12 countries that included 16 787 infants from 31 countries (of which 8 middle-income) were retained for analysis. Results indicate that non-breastfeeding practices pose a significant risk for severe RSV-associated ALRI and hospitalisation. Exclusive breastfeeding for >4–6 months significantly lowered hospitalisation, length of stay, supplemental oxygen demand and admission to intensive care units.ConclusionIn the context of no effective or standardised treatment for established RSV-associated ALRI, available evidence suggest that breastfeeding is associated with lower frequency and severity of RSV-associated ALRI, based on observational studies of variable grades of evidence and risk-of-bias. With both exclusive and partial breastfeeding benefiting infants who develop RSV-associated ALRI, breastfeeding should be promoted globally as an adjunct primary prevention; in addition to emerging immunoprophylaxis and maternal immunisation strategies.

Maternal awareness, acceptability and willingness towards respiratory syncytial virus (RSV) vaccination during pregnancy in Ireland

“…There were over 3600 cases of RSV reported in Ireland in winter 2018/2019, which was the highest number of notifications recorded before COVID‐19 pandemic, since RSV became a notifiable illness in Ireland in 2012 16 . While during the COVID‐19 pandemic and lockdowns RSV infection declined drastically, there has been a resurgence with even higher RSV rates once the stringent public health mitigation measures against COVID‐19 were discontinued 17,18 . Globally, in 2019, 33 million episodes of RSV‐associated ALRI, 3.6 million RSV‐associated hospital admissions, 26 300 RSV‐associated ALRI related in‐hospital deaths, and 101,400 RSV‐attributable overall deaths occurred in infants and children aged 0–60 months, with almost half of these occurring in infants under 6 months 19 .…”

Human Milk Oligosaccharides and Respiratory Syncytial Virus Infection in Infants

“…Although nirsevimab and palivizumab have acceptable effectiveness, these monoclonal antibodies are expensive and mostly available to high-income countries [ [19] , [20] , [21] ]. In contrast, breastfeeding, a universal primary prevention strategy to reduce infectious diseases in infants, consistently confers benefits against both the incidence and severity of RSV bronchiolitis in infants [ 22 ]. A systematic review of 19 studies comprising 16,787 infants from 31 countries concluded that not being breastfed poses a significant risk of severe RSV disease and hospitalization [ 22 ].…”

“…In contrast, breastfeeding, a universal primary prevention strategy to reduce infectious diseases in infants, consistently confers benefits against both the incidence and severity of RSV bronchiolitis in infants [ 22 ]. A systematic review of 19 studies comprising 16,787 infants from 31 countries concluded that not being breastfed poses a significant risk of severe RSV disease and hospitalization [ 22 ]. Conversely, exclusive breastfeeding for 4–6 mo significantly reduces hospitalization, length of stay, supplemental oxygen therapy, and admission to intensive care units [ 22 ].…”

“…A systematic review of 19 studies comprising 16,787 infants from 31 countries concluded that not being breastfed poses a significant risk of severe RSV disease and hospitalization [ 22 ]. Conversely, exclusive breastfeeding for 4–6 mo significantly reduces hospitalization, length of stay, supplemental oxygen therapy, and admission to intensive care units [ 22 ].…”

P-Wave Axis of Schoolchildren Who Were Once Breastfed

“…It is a recognized fact that breastfeeding contributes to children's cardiovascular and respiratory health in the short, medium, and long term. Regarding the respiratory tract, a 2018 meta-analysis reported that donor milk protects against bronchopulmonary dysplasia [1]; former and current research has found that infants who were breastfed had subsequently fewer lower tract respiratory hospitalizations than formula-fed infants [2]; a systematic review that summarizes the research on the link between breastfeeding and bronchiolitis from 2000 to 2021 shows that both exclusive and partial breastfeeding lower the severity of bronchiolitis [3]; and a 2021 meta-analysis restricted to cohort or randomized studies found that both any breastfeeding and exclusive breastfeeding are linked to a lower risk of getting childhood asthma [4]. In addition, emerging research suggests that more prolonged breastfeeding benefits lung function in later childhood, with the most consistent effect on increased lung growth and vital capacity [5].…”