Hey there bathhousers,
Wow, haven’t done one of these for a while but I just learnt something and feel the urge to share. I’ve been reading about how vaccines work and also about the geographical variation of disease.
This brings me to today’s post which as sciency as it gets round here so hold on to your autoclaves and let’s get stuck in.
Invasive pneumococcal disease kills over 1.5 million children each year according to the World Health Organization (WHO), Ninety percent of these deaths occur in the developing world. 
You might think that if a vaccine is available in Europe and the US then it should be made available in the developing world too. One of the main vaccines for Pneumococcal disease is called Prenvar. Prevnar is among Wyeth’s top revenue producers, with sales in 2005 of $1.5 billion. 
So on the face of it there is an effective vaccine used in Europe and the US that should be rolled out across Africa, seems like a straight forward case where the drugs exist, Pharma has recouped their investment from Western consumers, so there is a moral imperative to bring this drug to the people that need it. Perhaps, within our current system of IP as long as the rich world needs the same drugs then they can pay for the R&D costs and everyone can get the benefit, assuming the minefield of international IP law can be negotiated.
Unfortunately it’s not as simple as that. There are around 90 different bacteria (serotypes) which cause pneumococcal disease. Prenvar is formulated to prevent 7 of those strains. Unfortunately the prevalence of different strains varies geographically. The table below shows the results of a study to determine the relative prevalence in descending order for the developed and developing world . Bear in mind that ‘developed’ and ‘developing’ represent huge areas so there is likely to be a large amount of additional variation between regions. (the number represents serotype number)
The table below shows the 7 serotypes present in Prenvar and a new GSK drug Synflorix.
You’ll notice that the Prenvar vaccine is designed to prevent the most common strains in the developed world, as you might expect. Unfortunately the 3rd, 4th and 5th most common forms of the disease in the developing world are not covered by this vaccine.
This example illustrates why even if access to drugs developed for the developed world could be assured, in some cases, the efficacy wouldn’t be the same. Furthermore, If you’re going to go to the trouble to run a mass vaccination for a disease that kills millions, you’d at least want a drug that treated most of the common strains in your country, otherwise it could be expensive and ineffective.
Also in the table you can see another drug developed by GSK. Synflorix, which as you can see covers two of the missing serotypes and is therefore likely to add to the overall effectiveness significantly in the developing world. But if the missing serotypes aren’t prevalent in the developed world why did GSK develop this drug?
It was possible because of an advanced market commitment from Gavi  (the Global Alliance for Vaccines and Immunisation). This means that Gavi have committed to buying up to 300 million doses over 10 years and in return for this GSK have developed the drug.
In conclusion, in some cases the developing world will need drugs developed specifically for their own needs. Where there aren’t rich consumers with insurance companies and government funded healthcare, innovative financing mechanisms like advanced market commitments or perhaps publicly developed and owned IP will be needed to ensure that drugs get developed.
[ 4] (Pediatric Infectious Disease Journal
Volume 14, Issue 6 http://www.scopus.com/record/display.url?eid=2-s2.0-0029057617&origin=inward&txGid=z2jb5-sWfwbAl6CATF7Gvif%3a2)