Paediatrics.info

Respiratory Syncytial Virus (RSV) is the organism responsible for the majority of cases of bronchiolitis. Parainfluenza Virus (PIV) Type 3 typically causes bronchiolitis or croup. These respiratory tract infections are responsible for a large number of paediatric admissions during the winter months in temperate countries. A passive immunisation (Palivizumab) is available to protect against RSV but is very expensive and requires repeated doses to offer protection over the winter months. Therefore, it is only offered to high risk infants such as those with chronic lung disease. The development of an effective vaccine that could be offered universally to infants would have a dramatic effect on admissions to paediatric units.

A trial of a live recombinant vaccine for RSV and Parainfluenza Virus Type 3 is, therefore, an important development. The vaccine uses a bovine virus as an "entry vehicle" but includes RSV and PIV 3 genes engineered into its genome. As a "genetically modified organism" special approval was required from the Department for Environment, Food and Rural Affairs (DEFRA) before it could be "released" into the environment at 9 specially selected sites.