Visualizing a vaccine breaking new ground, and chains, in Africa

Guest post by Katie Leach-Kemon, a policy translation specialist from the University of Washington’s Institute for Health Metrics and Evaluation.

One of the biggest obstacles to expanding immunization to the remotest regions on the planet has been that vaccines must be kept refrigerated at low temperatures.

Keeping vaccines cool during their entire trek – from the manufacturer to a ship or airplane to a refrigerated truck down to the guy riding a bicycle with a cooler – is known as the ‘cold chain.’

A new vaccine created by Seattle-based PATH, with help from the World Health Organization and other partners, now indicates it may be possible to break free from these chains.

The vaccine, known as MenAfriVac, was designed specifically for the ‘meningitis belt’ of central Africa – a region that had seen tens of thousands of annual deaths from this disease, not to mention the survivors left brain damaged, deaf or otherwise disabled.

map-meningitis-belt-engSince the new vaccine campaign began, more than 150 million people have been vaccinated and disease rates have fallen significantly. Africa’s so-called ‘meningitis belt’ may soon disappear.

In addition, a new study of the vaccine’s use in the field is being hailed by some as evidence the cold chain may also soon go the way of horse-and-buggy.

The study, done in Benin, showed the MenAfriVac vaccine maintains effectiveness at temperatures up to 104F (40C) for up to four days. Eliminating the need to keep these vaccines cold at all times in settings where refrigeration can be hard to come by can dramatically reduce costs in countries where every penny matters. In Chad, researchers estimated vaccination costs could be cut in half by reducing the need for refrigeration. And as The Guardian reported, scientists think this could be done for other vaccines such as against cholera or yellow fever.

Using Global Burden of Disease (GBD) visualization tools from the Institute for Health Metrics and Evaluation (IHME), you can see how many people were dying from meningitis infection as the vaccine was introduced in 2010. (When IHME updates the tools to show disease trends through 2013, in the GBD Study 2013, we will be able to see how the death rate from meningitis infection changes following the introduction of MenAfricVac.)

First, let’s look at a basic time plot that maps death rates from meningococcal infection in West Africa between 1990 and 2010. The majority of meningococcal infection deaths in this region are caused by meningitis A. The vertical lines represent the “uncertainty interval” that results from weaknesses in the data. In basic terms, this means the rate of meningitis deaths could be as small as 24 per 100,000 people or as big as 45 per 100,000 people. The snapshot indicates that death rates decreased between 1990 and 2005 but stagnated between 2005 and 2010. We hope GBD 2013 results will show more dramatic declines in meningitis infection deaths in more recent years.

Death rates from meningococcal infection in children under 5 years in West Africa, 2010

MeninVaxTime

Note: Deaths from meningococcal infection include deaths caused by meningitis A. Meningitis A is responsible for most deaths in West Africa.

In 2010, meningococcal infection killed about 19,000 children under age 5 in West Africa. The screen grab below shows how death rates from meningococcal infection are highest in some of the poorest countries in the world—Burkina Faso, Niger, Chad, and Mali.

Death rates from meningococcal infection in children under 5 years around the world, 2010 

MeningMapIHME

The next screen grab is a square pie chart, called a treemap, that shows all causes of death in children under 5 years in West Africa.  The size of each box represents the percentage of deaths caused by a particular disease or injury. Red shows communicable, maternal, nutritional, and newborn causes of death, blue represents non-communicable causes, and green indicates different types of injuries.

Meningococcal infection (abbreviated in the screen grab as Mng-Mening) accounted for 1.14% of total deaths in children under 5 in West Africa in 2010. To put this in perspective, meningococcal infection caused a greater percentage of deaths in this group than tetanus, measles, or typhoid. The number of deaths caused by meningococcal infection in West African children was similar to the number caused by whooping cough.

Deaths from all causes in children under 5 in West Africa, 2010

MeningTreetMap

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  • http://www.villagereach.org VillageReach

    At VillageReach we’ve been studying
    the cold chain for over a decade in sub-saharan Africa. MenAfriVac is a huge step
    forward, yet for most vaccines the cold chain remains a significant barrier to
    vaccination. We’ve recently published a paper documenting the challenges
    of the cold chain at the last mile of delivery with examples of new
    innovations and approaches to improve cold chain monitoring and maintenance. http://villagereach.org/vrsite/wp-content/uploads/2009/08/Village-Reach_Keeping-the-Cold-Chain-Cold.pdf