Like most people who have grown up in the UK, I used to think of polio as more or less eradicated. I do remember one boy in my school with a leg in a brace but he still played games. And that was a long while ago. In the Central African Republic (CAR) I found proof that polio is frighteningly common.
This is why Merlin is aiming to vaccinate nearly half a million children. In Africa's forgotten country, there are villages where 94% of children have never received a vaccination. The consequences are clear and poignant. In Bawi, a small village in the north west of the country, it is still possible to find children with twisted limbs. In the next village, there are another six cases of polio - young children's lives blighted by a disease which can easily be vaccinated against.
Thanks to global efforts, cases of polio have fallen by 99% since 1988 and the disease is now only endemic in three countries - Pakistan, Afghanistan and Nigeria. Although a further 14 countries, including CAR, still carry the virus or are at high risk of importation, polio is now confined to a smaller geographic area than any at point in history.
World Polio Day in 2012 should be an occasion for celebration. However, a funding shortfall of almost $1 billion for 2012/13 currently threatens the milestone position we are in. This could expose countries like CAR to the risk of re-emergence, leaving more children vulnerable to contracting polio.
In a country where I have personally seen how years of war have all but destroyed healthcare services - to the extent that three quarters of the population live over 10 km away from a clinic - this would be devastating. The situation in other high-risk countries such as Chad and the Democratic Republic of the Congo is all too similar, which is why Merlin's work to provide children with vaccinations is so vital.
Our aim over the next three years is to provide 480,000 infants worldwide with three doses of vaccine by their first birthday to protect them from diseases such as diphtheria, tetanus and polio. We are under no illusions about this challenge; for example, some mothers, having seen their children vaccinated once for tuberculosis don't always understand that full protection against polio requires them to come back two more times. Fewer children receive each subsequent injection in CAR, with a drop in figures from 80% to 68% and then just 43%.
We responded by expanding health education in CAR. I am convinced that there are few obstacles which cannot be overcome with sufficient will. Merlin has delivered vaccines in seemingly impossible circumstances - from conflict zones in Afghanistan and Pakistan to remote areas of CAR which are accessible only by air.
World Polio Day gives us the chance to celebrate the fact that we might see this debilitating disease eradicated in our lifetime. That is my hope.
To find out more about Merlin's work in CAR, visit www.merlin.org.uk
Follow Carolyn Miller on Twitter: www.twitter.com/MerlinChiefExec