What is Respiratory Syncytial Virus (RSV)?Respiratory Syncytial Virus (RSV) is a very common RNA virus that causes cold-like symptoms and breathing problems, especially in young children. It is one of the leading causes of bronchiolitis (inflammation and blockage in the tiny airways of the lungs) in babies and children under 5 years old.1-4By the time they turn 2, almost all children will have had RSV at least once.5 It can affect both the upper airways (nose and throat) and the lower airways (lungs).1-3 In South Africa, RSV circulates throughout the year but usually peaks between February and May.3How Serious is RSV?Worldwide, RSV causes more than 3.6 million hospital admissions and around 100,000 deaths in children under 5 years every year. Most of these deaths (97%) occur in low- and middle income countries where hospital care is often limited.5
Image for illustration only
LRTI: Lower Resiratory Tract Infection
Image source: Adapted from Mazur N. et al.7How Does RSV Spread?RSV spreads easily from person to person through droplets in the air when someone coughs, sneezes, or talks.3,6A person can be contagious even before symptoms appear and usually remains contagious for 3 to 8 days after symptoms start.3Young children often catch it at crèches, daycare, or from older siblings at school.3The virus can also survive on hard surfaces (like countertops) for up to 30 hours and on softer items like tissues for < 1 hour.6Simple Ways to Protect Your Family:3
Cover your mouth and nose when coughing or sneezing (use a tissue or your elbow)
Wear a mask if you have symptoms to protect others
Wash hands frequently with soap and water (or use hand sanitiser)
Stay home when you or your child are unwell
Who is at Higher Risk of Severe RSV?
Premature babies6,7
Babies younger than 6 months6,7
Babies or children with lung problems, heart conditions, neurological conditions, Down syndrome, or weakened immune systems (including HIV)6,7
Babies whose mothers smoked during pregnancy8
Children living in households with tobacco smoke or biomass fuel exposure8
Families with two or more children under 5 years old8
Older adults (over 65) and adults with chronic conditions such as asthma, COPD, diabetes, or heart disease3
Common Signs and Symptoms of RSV:9Upper Respiratory Symptoms (Nose and Throat)
Runny or stuffy nose
Sore throat
Lower Respiratory Symptoms (Breathing and
Chest)
Cough (dry or with mucus)
Shortness of breath or trouble breathing
Fast breathing
Wheezing
Rattling or noisy breathing
Crackling sounds in the chest
Coughing up blood
Chest pain
General Body Symptoms
Fever
Feeling unwell or sick
Muscle aches
Headache
Weakness
Extreme tiredness
Changes in Behaviour
Poor feeding or feeding difficulties
Disturbed or restless sleep
How RSV Affects Children of Different Ages?Severe RSV can present differently depending on age:7
Newborns may appear very ill with sepsis-like symptoms or may have periods where they stop breathing for short times (called apnoea).
Babies and toddlers under 2 years most commonly develop bronchiolitis - inflammation of the small airways in the lungs.
Older children may also develop pneumonia.
In some infants, breathing difficulties can become severe and lead to respiratory failure, requiring hospital care. In rare cases, it can be life-threatening.7Are There Long-Term Complications?Many children who have a severe RSV infection in infancy (especially bronchiolitis) later develop recurrent wheezing. Around 30% to 50% of children who were hospitalised with RSV experience repeated wheezing episodes. For most children, these episodes become milder as they grow older. However, some may continue to have wheezing into their teenage years or even as adults. It is still not fully clear whether RSV directly causes these long-term breathing issues or whether some children are simply more prone to them.6How is RSV Treated?There is no specific medicine that cures RSV. Treatment focuses on supportive care to help your child breathe easier and stay comfortable while their immune system fights the virus. This may include:5
Gentle nose suctioning to clear mucus
Fluids (sometimes via a drip) to prevent dehydration
Supplemental oxygen if breathing is difficult
Note: Antibiotics do not work because RSV is a virus, not a bacterial infection.1
Maternal ImmunizationWith a new family member on the way, you are probably thinking about how you can help keep them healthy. Getting vaccinated while pregnant, also called maternal immunisation, gives you the ability to pass your antibodies to your baby through the placenta. And therefore, helps protect your baby from getting sick from the moment they are born.10-15What is maternal immunisation?During pregnancy your body naturally passes on antibodies that help protect your baby against bacteria and viruses in the first few months of life. Maternal immunisation helps you give your baby additional antibodies that help protect against a specific disease without them needing to get an injection themselves immediately after birth.10Maternal immunisations boost your immune system, and your body passes that natural protection to your baby in the womb. This strategy is used to protect infants from tetanus, pertussis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV) and influenza.10,13,16Maternal immunisation helps protect your baby in the first few months of life until your baby is old enough to develop their own antibodies through natural exposure to viruses and bacteria or through childhood vaccination.10,14How does it work?Vaccine-induced maternal antibodies are passed to your baby in 3 simple steps:10,13
You receive a vaccine during your second or third trimester
Your immune system produces antibodies that are passed through the placenta to your baby
Your baby is born with natural maternal antibodies, helping to protect them from geing sick
Is maternal immunisation right for you?
Is it safe for my baby if I get vaccinated while pregnant?
Is it safe for me?
How much protection can my baby get if I receive a vaccine while pregnant?
What vaccination options should I know about?
When during my pregnancy should I receive a vaccine?
References
Oppenlander K.E, et al. Respiratory Syncytial Virus Bronchiolitis: Rapid Evidence Review. Am Fam Physician.2023;108(1):52-57.
Li Y,et al. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet.2022;28;399(10340):2047–2064.
Joseph N, et al. Society for Maternal-Fetal Medicine Statement: Clinical considerations for the prevention of respiratory syncytial virus disease in infants. American Journal of Obstetrics & Gynecology.2023;230:B41-B49.
Walsh EE, Hall CB. Respiratory Syncytial Virus (RSV). Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases.2015:1948–1960.
Mazur N, et al. Severe respiratory syncytial virus infection in children: burden, management, and emerging therapies.Lancet.2024;404(10458):1143-1156.
Wang X,et al. Global disease burden of and risk factors for acute lower respiratory infections caused by respiratory syncytial virus in preterm infants and young children in 2019: a systematic review and meta-analysis of aggregated and individual participant data. Lancet.2024;403:1241–53.
Colosia A, et al. Systematic literature review of the signs and symptoms or respiratory syncytial virus. Influenza Other Respi Viruses.2023;17:e13100.
Simionescu AA, Streinu-Cercel A, Popescu, FD,et al. Comprehensive Overview of Vaccination during Pregnancy in Europe. J Pers Med. 2021;11:1196.
Benowitz I, Esposito DB, Gracey KD, et al. Influenza vaccine given to pregnant women reduces hospitalization due to influenza in their infants. Clin Infect Dis. 2010;15;51(12):1355-61.
Baxter R, Bartlett J, Fireman B, et al. Effectiveness of Vaccination During Pregnancy to Prevent Infant Pertussis. Pediatrics. 2017;139(5).
Kampmann B, Madhi SA, Munjal I, et al. Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants. N Engl J Med. 2023;20;388(16):1451-1464.
Cinicola B, Conti MG, Terrin G, et al. The Protective Role of Maternal Immunization in Early Life. Front Pediatr. 2021; 9:638871.
CDC. Tdap Vaccination for Pregnant Women. Published October 2024. https://tinyurl.com/bdf7p7dy Accessed July 2026.
Simões EAF, Pahud BA, Madhi SA, et al. Efficacy, Safety, and Immunogenicity of the MATISSE (Maternal Immunization Study for Safety and Efficacy) Maternal Respiratory Syncytial Virus Prefusion F Protein Vaccine Trial. Obstet Gynecol. 2025;1;145(2):157-167.