09 September 2015
The CoMO Scientific Advisory Group:
Professor Robert Booy, Dr Priscilla Robinson, Dr Ron Gold,
Dr James Stuart and Professor Catherine Weil-Olivier
The new meningococcal B vaccine has been licensed in many jurisdictions in the past 2 years. Since 2014, national health authorities have implemented regionally focused campaigns to respond to either outbreaks of Men B invasive disease (e.g. In 2 American Universities) or durable high incidence of Men B disease in some countries (e.g. Quebec hyper-endemic regions). As of September 2015, more than 100,000 doses of the Men B vaccine have been administered - surveillance has confirmed the safety profile and vaccine acceptance in targeted populations has been high. The control of the outbreaks, with large reductions in the incidence of Men B disease, suggests the vaccine is effective against Men B. It is too early to know the duration of protection afforded for those vaccinated.
We also would like to know more about the impact of the Men B vaccine on the nasopharyngeal carriage of the bacteria and thus whether there is an impact on transmission of the germ. We would like to know if the vaccine reduces circulation of the Men B germ so that there is protection of unvaccinated people (this indirect impact is called herd immunity). Finally, we also need to confirm that the immune impact of this vaccine is sufficient to cover the wide variety of Men B clones found in different countries.
As yet only one national government has decided to recommend and begin universal use of the vaccine for its infants - the UK. What makes the UK so very different? Put another way, will other countries follow suit and introduce the 'Men B' vaccine, and if so, why?
Men B’s incidence, and concomitant death or disability, may have become too infrequent to justify in economic terms (cost-benefit analysis) implementing a Men B vaccine program for all children. Curiously, despite the lack of a routinely used vaccine, the incidence of Men B disease has been on a downward trajectory over the past 5-15 years in almost all developed countries, without exception. It is debatable what the principal drivers of this are, but likely factors are rising population immunity to Men B and reduced smoking rates - because of these factors the colonisation rate of Men B in the throat (harmless carriage) has declined, which in turn has probably led to reduced transmission of the Men B germ within populations.
When the Hib vaccine was introduced, a quarter of a century ago, the risk for a child aged <5 years of developing life-threatening Hib disease was about 1 in 500 children in developed countries like UK, US and Australia. Back then Hib and the meningococcus (Men B accounting for over half of meningococcal disease) were neck and neck in causing serious infections in children. The risk today for children of life-threatening Men B disease is <1 in 5,000 by the age of 5 years in developed countries. However, when cases do occur, the fatality rate is about 5% and can reach 25% in cases of severe shock, while another 25% are left with major debilitating long-term complications like deafness, amputation, severe scarring, or intellectual and behavioural difficulties.
The UK decided to implement the Men B vaccine following negotiation with the vaccine supplier, GSK that may well have produced a much lower, favourable (‘loss-leading’) price. We urgently need a better handle on the true long-term costs of Men B disease in children to adequately inform deliberations of government agencies on the cost-effectiveness of the Men B vaccine. Sequelae, i.e. the complications of disease, may even worsen over time or may not become apparent until years after disease in an infant. Some children require many operations over decades to address the damaging after-effects of this potentially disastrous disease.
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The CoMO Scientific Advisory Group (CSAG) are a group of medical experts and clinicians that advise CoMO's Governing Council on meningitis issues and immunisation projects across CoMO's three regions- Americas, Asia Pacific and Europe Africa. To find out more about its members please click here.