The UK Health Security Agency (UKHSA) has issued warning letters to parents regarding an increase in whooping cough cases in Lincolnshire and the East Midlands. Symptoms include prolonged coughing, retching, a ‘whoop’ sound on breathing in, and rib pain. Parents are advised to seek medical attention if their child experiences these symptoms. Vaccination is emphasized as the most effective protection against whooping cough, and children should receive vaccinations at specific intervals. Those affected are asked to self-isolate until antibiotic treatment is complete or three weeks after coughing bouts start.