RSV (short for respiratory syncytial virus; “syncytial” is pronounced syn·cy·tial [sin-sish-uhl]) is a common virus that can cause chest infection in babies, children and adults.1,2 RSV is highly contagious and activity tends to start around April to May, with the peak occurring during the winter months, although the timing may vary depending on where you live in Australia.2,3 The RSV season is usually a few weeks before the influenza season; however, the timing has been less predictable following the COVID-19 pandemic.3 RSV outbreaks can be serious, causing a range of lung and airway illnesses that can vary from mild to severe, sometimes leading to hospitalisations.2 RSV causes thousands of hospitalisations among children each year.2