Smallpox vaccination permanently protected the person being vaccinated.
The Joint Committee on Vaccination and Immunisation advises UK government departments on vaccination issues, and has a programme to vaccinate all children between the ages of two and 16, starting with the youngest.
The low incidence of vaccine-preventable disease was probably a result of successful vaccination.
One example is the HPV vaccination programme for cervical cancer in Rwanda, enabled by a donation from Merck.
For those who have been, we often do not have vaccination cards as they fled from burning villages," says the 27-year-old nurse.
In a single morning, they cover the ground – malaria prevention, the virtues of breastfeeding, malnutrition screening and vaccination.
It said it was increasing operations to help more families with heating, children's clothes and a vaccination programme to protect up to a million children against measles and other diseases.
Polio remains a serious threat in Somalia, particularly to the children, and we must continue our intensive vaccination campaigns".
Somalia suffered its first outbreak of polio in six years in May 2013, starting with a two-year-old girl in Mogadishu and sparking a nationwide vaccination campaign by the Somali authorities supported by the World Health Organisation and Unicef, the UN children's agency.
Steven Lauwerier, Unicef's representative in Somalia, said: "It is excellent news that Somalia has seen six months without a single polio case and credit must be given to all those involved in the huge vaccination effort.
Polio, a highly contagious viral disease that causes lifelong paralysis or even death, has been the target of massive education and child vaccination campaigns in several countries.
