Back to cover page

Why can't all students be vaccinated against meningitis?
After recent deaths among students, Robert Booy looks at the inflammatory issue of preventing meningococcal disease

Meningitis provokes considerable alarm in both the public and the medical profession. Bacterial meningitis is the most deadly form and the meningococcus is, far and away, the most common cause of bacterial meningitis in children and young adults. From middle age onwards, the pneumococcus is the principal culprit. This year in England and Wales there are likely to be in excess of 2500 notifications of meningococcal disease and 250 deaths, one quarter in the 15-24 year age group. An important fact is that the most deadly form with which meningococcal disease presents is septicaemia where the patient has fever, malaise, myalgia, cold peripheries, and a haemorrhagic rash, but no evidence of meningism. Septicaemia accounts for more than 80% of the deaths from meningitis but this is still not widely known. There are two peaks of meningococcal disease, the larger in infancy, after transplacentally acquired maternal antibody protection has waned, and another in the later teenage years. Cases peak in late autumn and winter, and there is no doubt that first year students living in halls of residence are at greater risk, perhaps twice that of their counterparts living at home. This naturally leads to the question: why can't students be vaccinated?

Peak ages for outbreaks
In focusing on recent outbreaks in colleges and universities, however, the media has failed to appreciate that teenage cases actually peak in the two years before university entry: earlier in females than in males. In fact, the population at increased risk extends from 2 months to 20 years of age, so were an effective vaccine available it would need to be offered to about 14000000 children and young adults in England and Wales alone, a daunting­ and very expensive­though not impossible task.

Neisseria meningitidis­a potential killerA student receives the meningitis vaccination at Southampton University after the outbreak this year

Different types of meningococcus
There are other important issues to consider. The meningococcus is not a single foe but many. Until recently, approximately 70% of cases were caused by the group B organism, for which there is as yet no licensed vaccine. In 1997 the proportion of group B cases in the United Kingdom is likely to be between 50% and 60%. In North America groups Y and C have both recently become much more common. One strain (clone) of group C (serotype 2a) has been responsible for most of the recent outbreaks in schools and universities in Britain. There is a licensed vaccine for group C but it is effective only in children from 2 years of age onwards. A reasonable question at this point might be: Why can't all school and university students be vaccinated against meningococcal disease?

The vaccine
The current vaccine consists of purified polysaccharides from the group C capsule. It elicits T cell independent immune responses and no memory.

Protection lasts only two to three years. It might be reasonable to consider giving widespread group C vaccination to children over 2 years of age, as in Canada in 1993 when a substantial outbreak occurred in Quebec, except that an improved vaccine should soon be on the market, hopefully in the next couple of years. It is known as a conjugate vaccine since the polysaccharides of group C is chemically linked (conjugated) to a carrier protein. Phase II trials in the United Kingdom and elsewhere suggest that the vaccine is safe and immunogenic and will provide longer lasting protection not only to children and young adults but also to infants.

A student receives the meningits vaccination at Southampton University after the outbreak this year

There is evidence that prior receipt of the plain group C vaccine may produce tolerance and so lessen the response to a subsequent dose of group C conjugate vaccine. This is another reason why it may be better to wait for the new vaccine.

Risk factors for students
What can be done in the meantime? Understanding risk factors may help some students to lessen their risk. There are probably several reasons why older teenagers are at greater risk. The onset of "adult" behaviour like kissing on the mouth, smoking, illicit drug use, and going to smoky crowded rooms, bars, and parties may aid transmission or invasion of the meninogococcus from the nasopharynx into the bloodstream. In most people the meninogococcus usually remains as a harmless commensal in the throat. Viral respiratory infection (for example influenza, Epstein Barr virus), psychological and physical stress, and human genetic factors may also contribute to the development of meningitis. A national study is beginning early next year to try and untangle the relative contributions of these risk factors.

Early detection saves lives
Until routine vaccination is introduced there are a few vital points to remember. Early recognition of the non-blanching haemorrhagic (petecial or purpuric) rash by a student or a friend should prompt an urgent appointment with the general practitioner, who can give intravenous penicillin, a life saving intervention. Although meningitis has typical symptoms such as headache, stiff neck, fever, and photophobia, the early symptoms of septicaemia may be subtle; at onset the rash may fade under pressure, and a student may easily interpret the malaise and myalgia as a flu or a hangover. Frequent checks on an ill friend can increase the chance of an earlier diagnosis.

Conclusion
Where there are outbreaks (two or more cases of probable or definite infection caused by the same strain) the usual practice is to try and identify a group in which the organism is most likely to be circulating (for instance, a hall of residence), then offer immediate antibiotic prophylaxis with Rifampicin or Ciprofloxacillin to clear nasopharyngeal carriage and prevent transmission, as well as group C vaccine if the cause of the outbreak is that serogroup.

Contact addresses

	Meningitis Research Foundation 13 High StreetThornbury, Bristol BS12 2AE Tel: 01454 413344 (24 hour helpline)
	National Meningitis Trust Fern HouseBath Road, Stroud Gloucestershire GL5 3TJ Tel: 01453 751738