The 2026 respiratory syncytial virus (RSV) season has ended.
RSV is a leading cause of bronchiolitis and lower respiratory tract infections (LRTI) in young children and can cause severe illness in infants. It is highly contagious, spreads primarily through respiratory droplets, and reinfections can occur. Risk factors for severe RSV-associated disease include prematurity, congenital heart disease, chronic lung disease of prematurity, neurological conditions, immunodeficiency, lack of breastfeeding, HIV infection or exposure, and age under 6 months.
Over the past decade, excluding the COVID-19 pandemic years 2020 and 2021, the RSV season in South Africa has typically begun around mid-February, with onset ranging from late January to late February. During the past 2 years, the start of the season was delayed compared to previous seasons. The 2026 season began in week 11 (week starting 9 March 2026), when the RSV detection rate among children aged <5 years enrolled in inpatient pneumonia surveillance at public hospitals exceeded the seasonal threshold and was sustained above the threshold for two consecutive weeks (Figure 1). RSV activity subsequently increased and peaked in week 25 (week starting 15 June 2026) at the moderate activity level, with the season ending in week 34 (week starting 17 August 2026).
Message to clinicians
Although the 2026 RSV season has ended, sporadic RSV infections may continue to occur outside the defined seasonal period. Clinicians should therefore continue to consider RSV in the differential diagnosis of patients presenting with respiratory illness, particularly young infants and children at increased risk of severe disease.
Prevention of RSV
Measures to reduce the spread of RSV and other respiratory viruses remain important throughout the year, even after the defined RSV season has ended. These include avoiding close contact with people who are ill, regular handwashing, avoiding touching the mouth, eyes and nose, and covering coughs and sneezes appropriately. Individuals experiencing respiratory symptoms should stay at home where possible to reduce transmission to others.
During the RSV season, additional RSV-specific preventive options are available for groups at increased risk of severe disease. Palivizumab, which requires monthly administration during the RSV season, has been available in South Africa for some time, although its high cost may limit its use. Long-acting monoclonal antibodies are also available in the private sector for infant protection, while maternal RSV vaccination is available in the private sector to protect infants. Introduction of maternal RSV vaccination into the public sector is being considered but is not currently available. As these interventions are targeted to specific groups and, in some instances, timed in relation to the RSV season, general measures to reduce respiratory virus transmission remain important throughout the year.
Where to find updated data
Weekly reports documenting respiratory pathogen circulation in South Africa, including influenza, RSV, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Bordetella pertussis, are available here.
