**2.7 Sourcing of vaccines**

The developing countries vaccine manufacturers' network (DCVMN) is a public health driven, international alliance of manufacturers trying to strengthen vaccine supply through information and professional training programs, technology improvements, innovative vaccine research and development, encouraging transfer initiatives, to improve availability of safe, effective and affordable vaccines. Three goals were proposed for vaccines. First, to ensure uninterrupted supply of affordable and suitable vaccines for GAVI. Second, improve market dynamics information and expertise to solve vaccine access challenges. Third, strengthening global health and manufacturers' partnerships to enable better alignment of goals, alignment with global strategy and coordination of internal investments [43].

### **2.8 Negative impact of population explosion**

Civil unrest is common in developing countries and this has led to migration of millions of people. There is increased movement by land, air and sea. In Northern Nigeria, activities of Boko Haram terrorist have caused several families to abandon their homelands and converge on Internally Displaced Peoples camps where health care services are poor and even non-existent in some cases. Many children are born in these camps, but vaccination activities may not be sustained at the desired national vaccination level. Wars and famines or other natural disasters increase mortality due to measles. In 2000, measles was responsible for 22% of deaths in children less than 5 years of age and 17% of deaths in children aged 5–14 years in Ethiopia [44]. Increased air travel by people within some regions in developing countries has been reported. For local flights, cabin air flow may not be as reliable a barrier to the spread of measles virus. Several measles reports, including index cases and apparent secondary cases on flights, have been reported in which transmission on board the aircraft appeared likely and which included seating information for both index (primary) and secondary case [45].
