A new vaccine could end polio in Nigeria

A team from Imperial College, London - writing in the New England Journal of Medicine have found that an improved version of the polio vaccine is up to four times more effective at protecting children against the disease.

Nigeria is one of only four countries in which polio still has to be eliminated and accounts for more than 80% of global cases of the disease.

The monovalent oral poliovirus vaccine, known as mOPV1, has been used in Nigeria since February 2006 and the number of reported cases of polio in the country fell by 75% between 2006 and 2007. The latest study shows that just one dose of mOPV1 gives a child in Nigeria a 67% chance of being protected, compared with a 16% chance after receiving the standard trivalent vaccine.

However, the researchers warn that although the monovalent vaccine is proving very effective, many more children need to be immunised if the polio virus is to be eliminated in Nigeria.

In the north west zone of the country, where the majority of new cases are found, 21% of children report never having received a single dose of the vaccine and a further 55% have received fewer than the recommended four doses.

The World Health Organisation says that operational problems need to be overcome in order to eradicate polio in Nigeria.

India is the other country that carries most of the global burden of polio.