Why immunization and its challenges?

Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by administration of a vaccine. Vaccines stimulate the body's own immune system to protect the person against subsequent infection or disease (1). Immunization saves 2 to 3 million people every year against contagious and life-threatening vaccine-preventable diseases (1, 2). We have to say that the knowledge of immunization is a gift to humankind for that we have safe, effective and affordable preventive measure. However, there are various issues that still remain as challenges to health system at every level. 

As a health professional having years of first hand knowledge or experiences of conducting mass vaccination and surveillance of vaccine preventable diseases (VPDs), let me throw light so as to understand the public health landscape that may be similar in most of the low income countries (LIC). First, there is an increasing divide between rich and poor in terms of socio - politico - economic opportunities. This divide exists in both high income to low income countries across all continent although this may be more pronounced in Asia, Africa and South America. Now, there are also other differences that are visible between urban and rural population. The most remarkable would be the growing number of slums, which have resulted from poverty due to unequal distribution of wealth, population explosion, unemployment and destruction of habitat. In this population, thousand and thousands children as well as adults / old people get sick and die as result of preventable illness or diseases related with poor water supply / sanitation, food scarcity leading to malnutrition and crowding exposing people to various respiratory illness. This means many children miss the opportunity to get vaccinated or even if they get vaccinated, they may not complete the doses, so why does this happen? This brings us to another level of daily challenges that a family has to go through. I will not come to this discussion right now. Another problem, we see most of the time in low income countries are issues related with access and utilization of immunization services. The challenges that we face the most is cold chain maintenance of the vaccines, which can either freeze or heat sensitive. So maintaining cold chain and providing vaccine in safe and potent vaccine is one challenge that requires high priority and importance. Another common problem that we see is inadequate human resource in hard to reach communities. Many of times, parents miss their children get vaccinated just because there are no vaccinator in their village. Is this fair?

Reference:
1. http://www.who.int/topics/immunization/en/
2. http://www.cdc.gov/globalhealth/immunization/