Meningitis B outbreak was severe because bacteria borrowed DNA, scientists say

Scientists have found why an outbreak of meningitis B in Kent earlier this year was so serious. The UK Health Security Agency and Oxford University say the bacteria picked up genetic material from other bacteria that normally live harmlessly in people's throats. The process is called horizontal gene transfer. It created a new, more dangerous variant that caused more severe illness and was harder for the immune system to fight. The outbreak was the largest and fastest growing in modern times. It was linked to a nightclub in Canterbury and spread through close social mixing among students, including kissing and sharing drinks and vapes.

More than 20 people were infected. Twenty-one were treated in hospital, nine needed intensive care, and two young people died. Scientists sequenced the bacteria and compared it with meningococcal genomes from international databases. They concluded the outbreak strain had borrowed DNA from other bugs. The new variant was more effective at causing severe disease, partly because people had not encountered it before. It was more severe but not more transmissible. Experts think that because patients became very unwell very quickly, they mixed less and did not pass it on as widely. Similar intense clusters have been seen before, including an outbreak at the University of Southampton in 1997. Outbreaks remain rare but unpredictable, so vigilance is still needed.

The current meningitis B vaccine works against this strain. An emergency vaccination programme was launched for students in Kent at the time of the outbreak. A wider programme is now offering vaccines to students going to university this autumn. For the first time, the NHS is offering the vaccine to young people who finish school year 13 this summer, as well as under 25s starting university. Students are being offered two doses over the next couple of months. The first dose is available until the end of the year. The meningitis B vaccine was not part of the UK routine schedule until 2015, so many people now leaving school missed it. Freshers are around seven times more at risk of meningitis than other young people of the same age. Two meningitis vaccines are offered in the UK: ACWY at school and B for babies.

Students are being urged to know the symptoms and seek medical help quickly. These include fever, a stiff neck, a rash that does not fade under pressure, sensitivity to light, severe headache and confusion. They are also being asked to check on friends who feel unwell, especially during freshers week. Personal accounts from students who fell ill show how quickly the disease can develop. Tiff O'Connor, a first-year student in Bristol, was found convulsing in bed after her cat alerted her mother. She was put into a medically induced coma and her family were told to say goodbye. She woke up paralysed from the neck down and was told she might never walk again, but took her first steps three and a half months later. Ella, a first-year at Bath Spa University, spent nine days in hospital and has lasting hearing damage. She said the vaccine was not available to her before university but is now free this summer.