Britain has declared a national incident amid the “unprecedented” spread of meningitis that has claimed two young lives.

Five new cases of the potentially fatal brain infection have been found in Kent in south-east England, taking the total ‌to 20.

British Health Security Agency chair Susan Hopkins said the outbreak had an “explosive nature”.

“This looks like a super-spreader event, with ongoing spread within the halls of residence in the universities,” she said.

All of those infected and linked to the outbreak so far are young adults.

A 21-year-old student at the University of Kent and a 18-year-old student, named only as Juliette, at a school in the town of Faversham have died.

The agency said it was also aware of a baby, not yet linked to the outbreak, with confirmed meningococcal ‌group B ‌infection.

Health Secretary Wes Streeting ​described the outbreak as “unprecedented” in terms of its spread.

A major vaccine scheme is being rolled out for students at the University of Kent. But pharmacies are reportedly running out of supplies amid a surge in demand.

A vaccine rollout in the sports hall at University of Kent campus in Canterbury. Photo: AAP

Signs and symptoms of meningococcal meningitis and septicaemia can include a fever, headache, rapid breathing, drowsiness, shivering, vomiting and cold hands and feet, the agency said.

Septicaemia can also cause a characteristic rash that does ⁠not fade when pressed with a ‌glass.

Young ​people going on to university or college for the first time are particularly at ​risk of meningitis ‌because they mix with other students, some of whom are unknowingly carrying ​the bacteria at the back of their nose and throat.

Streeting said most cases so far were linked to the Club Chemistry nightclub in Canterbury between March 5-7.

Health authorities are also investigating the potential spread of the outbreak to other areas. Britain’s Mirror newspaper reports that a game development, VFX and animation school in North Greenwich, had emailed students this week to report someone was “hospitalised over the weekend and diagnosed with meningitis”.

A secondary school pupil in Weymouth, Dorset, has also contracted meningococcal disease, which can cause meningitis. Local media said parents had been told of an “isolated” case.

Elsewhere, French authorities have revealed a person was admitted to hospital with meningitis, linked to the Kent outbreak. The French Ministry of Health said the person fell ill in France after coming back from England and is now in a “stable” condition.

“The patient has been hospitalised and their condition is stable. All possible measures have been taken to limit the spread of the infection. People who were in risky contact with the patient have been informed and an antibiotic treatment has been offered to them,” a spokesperson said.

The UKHSA said it had ​administered about 2500 doses of antibiotics across  Kent.

“As a further precaution and together with the NHS, we are beginning to roll out a targeted MenB vaccination program,” Trish Mannes, UKHSA regional deputy director for the south-east, said.

“This will initially be offered to 5000 ​university of Kent students resident at the Canterbury campus, with the possibility that ​it may be extended, ⁠as it is kept under continual review.”

-with AAP