In today's update, the UKHSA confirmed 18 laboratory cases and 11 notifications under investigation.

Meera Chand, strategic response director, said: ‘The latest laboratory analysis by UKHSA confirms that the vaccine being offered to students and other eligible groups should cover this circulating strain of MenB, with further analysis ongoing to understand more about the strain.'

As of 5pm on Thursday 19 March, 2,360 vaccinations have been given and 9,840 doses of antibiotics have been administered.

An expansion of the vaccination programme was announced by the UKHSA yesterday to everyone who has been offered preventative antibiotic treatment as part of the outbreak.

Preventative antibiotics – and vaccination – will also now be offered to the 6th form students (years 12 and 13) in schools and colleges in Kent where confirmed or probable cases are identified.

Students are being advised to continue to attend schools and colleges as normal. 

Around 20,000 vaccination doses are also being released to meet private demand to up to 2,000 pharmacies.

Professor Susan Hopkins, chief executive of the UK Health Security Agency, said: ‘By extending the vaccination programme to everyone who has been offered preventative antibiotics, we are taking an important additional step to protect those most likely to have been exposed. The message is simple: if you have had the antibiotic, you are also eligible for the vaccination.'

Speaking on Wednesday, health and social care secretary, Wes Streeting, said the emergency was ‘not currently a national incident'.