The decision to introduce a new vaccine into a programme is never straightforward, and there are several groups involved prior to the decision.

One of these is the pharmaceutical industry. There’s a fair bit of ill-feeling expressed towards “big pharma” – perceived by some as rapacious organisations, out to make a profit from poor sick people. But when it comes to vaccination the margins for manufacturers are generally small, and the development and manufacturing costs high – a number of vaccine manufacturers have gone under in recent years because it’s so hard to make a profit. Those manufacturers who do succeed in getting a new vaccine to market will naturally want to make a return on the huge sums it will have cost them to do so.

Other groups are the patient support groups for the diseases the vaccine is designed to prevent, and the professionals who treat these diseases.

Finally there are the governments who will have to pay for the vaccines if they are introduced into a national, public-funded vaccinated programme; and their public health advisors. If the vaccination programme will clearly save more money (by preventing illness) than it costs, the decision is not too difficult; but otherwise it is harder to justify the cost of the programme.

Meningococcal disease causes meningitis and septicaemia, particularly in babies and young children. About one in ten of those who get septicaemia will die.

Expert paediatricians from big hospitals see most of the cases from a large population. For them, it is a common and distressing disease; and anything that could prevent cases of this disease must be a good thing.

From a public health perspective, however, it is far less obvious. Despite the paediatricians’ impressions, in population terms the illness is not that common (roughly 2 cases for every 100,000 population per year) and, if anything, seems to have become a little less common recently.1-3. Most cases are not ill for very long: those that survive soon recover. Compared to the costs of many other conditions with a longer duration of illness, meningococcal disease does not – from a cold, financial point of view – cost the taxpayer all that much. Even if you put a high value on life the number of deaths (and therefore the value of preventing these deaths), is not so very large.

Most meningococcal disease cases in developed countries – nearly 90% of them in England and Wales – have disease caused by a particular subset of the germ known as “serogroup B”.4 Developing a vaccine that works against this serogroup has proven highly problematic but, soon, one or more vaccines may be available.5-7

Studying the impact of a new vaccine for something as uncommon as meningococcal disease is tricky. You can measure the proportion of vaccine recipients who have laboratory markers that suggest they’re immune; but until a vaccine for has been used for some time it is hard to assess how effective it will be in the real world. With a disease this uncommon, you’d have to vaccinate an awful lot of people to prevent a noticeable number of cases. And even if the vaccines are effective against currently circulating strains of serogroup B meningitis germs, it is possible that strains of the disease that aren’t prevented by the vaccine will replace them, so that in a few years’ time the vaccines will be a lot less effective.

Even assuming that the vaccine is and will remain effective, it is unlikely to be cheap, having taken so many expensive years to develop. Skeptical public health practitioners know that money spent on vaccination can’t be spent on anything else, so the health gain has to be greater than you could achieve elsewhere.

A recent study may help to unblock this impasse.8 It looked at the long term sequelae of meningococcal group B disease. I dismissed these above, as they have been so hard to quantify; but the disease damages the brain and other organs. The damage it does can reduce patients’ subsequent ability to contribute to society, or mean that they have additional medical or social needs that have to be met. According to the study, about a tenth of survivors had major sequelae including major amputations, very low IQ, seizures, or deafness; as many as a third of survivors had minor deficits; and most had a poorer IQ than controls. This damage – and the costs associated with it – should be considered when weighing the benefits against the costs of vaccination.

I’m not clever enough to them do myself; but these data will help the boffins who do economic analyses to provide some more realistic answers to the public health practitioners’ and politicians’ question: vaccinating people with these new vaccines – is it worth it?

References

1. Comparison of meningococcal disease surveillance systems – United States, 2005-2008. MMWR Morb Mortal Wkly Rep 2012;61:306-8 PMID: 22552207. (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6117a3.htm?s_cid=mm6117a3_e).

2. Health Protection Agency. Meningococcal disease: Epidemiological Data: Meningococcal Reference Unit isolates of Neisseria menengitidis: England and Wales, by serogroup & epidemiological year, 1998/99-2009/10* 2011; Updated 29 July 2011; Accessed: 2012 (August 6): (http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1234859711901).

3. Health Protection Agency. Meningococcal disease: Epidemiological Data: Laboratory Confirmed Cases of Meningococcal Disease England & Wales Five Weekly Moving Averages: 1999 to 2009. 2011; Updated 29 April 2010; Accessed: 2012 (August 6): (http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1235119129097).

4. Ladhani SN, Flood JS, Ramsay ME, Campbell H, Gray SJ, Kaczmarski EB, et al. Invasive meningococcal disease in England and Wales: implications for the introduction of new vaccines. Vaccine 2012;30(24):3710-6 PMID: 22429756. (http://www.sciencedirect.com/science/article/pii/S0264410X12003593).

5. Gossger N, Snape MD, Yu LM, Finn A, Bona G, Esposito S, et al. Immunogenicity and tolerability of recombinant serogroup B meningococcal vaccine administered with or without routine infant vaccinations according to different immunization schedules: a randomized controlled trial. JAMA 2012;307(6):573-82 PMID: 22318278. (http://jama.jamanetwork.com/article.aspx?articleid=1104956).

6. Richmond PC, Nissen MD, Marshall HS, Lambert SB, Roberton D, Gruber WC, et al. A bivalent Neisseria meningitidis recombinant lipidated factor H binding protein vaccine in young adults: Results of a randomised, controlled, dose-escalation phase 1 trial. Vaccine 2012 (in press)(0). (http://www.sciencedirect.com/science/article/pii/S0264410X12010900).

7. Sadarangani M, Pollard AJ. Serogroup B meningococcal vaccines–an unfinished story. The Lancet Infectious Diseases 2010;10(2):112-124. (http://www.sciencedirect.com/science/article/B6W8X-4Y7MPXW-R/2/3887c2bb3cbc542121a424761cb2e821).

8. Viner RM, Booy R, Johnson H, Edmunds WJ, Hudson L, Bedford H, et al. Outcomes of invasive meningococcal serogroup B disease in children and adolescents (MOSAIC): a case-control study. The Lancet Neurology 2012. (http://linkinghub.elsevier.com/retrieve/pii/S1474442212701801).