An investigation is underway into an outbreak of hepatitis A in the Caerphilly area.
Public Health Wales says four cases have been identified all of whom are associated with Glyn-Gaer Primary School at Hengoed.
As a precaution vaccination is being offered to pupils and staff who may be at risk through socialising and playing together in the school.
Public Health Wales says due to the long incubation period of hepatitis A more cases are expected.
People are advised to contact their own GP if they have any concerns about their health or their child’s health.