A pupil from Tiverton High School is recovering in hospital after contracting meningitis.
The teenager was admitted to the intensive care unit at the Royal Devon and Exeter Hospital earlier this week, but he is now said to be responding well to treatment.
Parents of all pupils at the school have been sent letters warning them of the symptoms.
A second, younger, boy who lives just a few miles away was also admitted to the same hospital this week with symptoms of meningitis, but has now been transferred to Bristol.
Schoolgirl victim
Public health officials have ruled out any link between the cases.
Dr Mark Keeley, a Devon consultant in communicable diseases, said: "Single cases are not uncommon. We have taken the appropriate action in giving antibiotics to household contacts and kissing contacts.
"We feel that now we have warned parents about the symptoms of meningitis that we have followed national guidance."
On Tuesday a 15-year-old pupil at Fowey Community College in Cornwall died of meningitis.
Isis Clemo, of St Blazey, was admitted to the Royal Cornwall Hospital, Truro, on Monday in what was described as "a very serious condition".
She was diagnosed as suffering from bacterial meningitis and died on Tuesday afternoon.