Eradicating Viruses — Lessons from the Campaign Against Polio in India and Nigeria
Coronavirus (COVID-19) has reached pandemic levels across the world, with over half a million cases worldwide. There are early reports that vaccines are being developed, but these are unlikely to be ready for distribution for at least a year. While we do not yet know how this disease will spread over the coming months and years, it is timely to look back at efforts to eliminate other viruses to understand what makes an immunization campaign effective.
A recent review article from the International Journal of Translation Medial Research and Public Health studied polio eradication efforts in Nigeria and India. Polio is an infectious disease caused by a virus, which can lead to permanent muscle damage and disability. The original vaccine was developed in the 1950’s by Jonas Salk. While the vaccine led to a dramatic reduction in the rates of polio, public health officials have not been able to entirely eradicate the disease. Today, a handful of cases of polio reported world-wide remain, mainly in impoverished countries with limited health infrastructure.
The review article focuses on comparing the eradication of polio in India and Nigeria. Nigeria has not had any cases of wild polio since 2017, while India was declared polio-free in 2012. These two countries are useful comparisons since India is viewed as a success story, while Nigeria had more difficulty fighting the disease. The authors of the review screened over 3,000 research papers to find articles that most directly addressed the eradication of polio in Nigeria and India. From the papers that remained, the reviewers distilled the most important themes in an attempt to address why India performed better than Nigeria.
One of the clearest findings was the importance of vaccine choice. There are several formulations of the polio vaccine, though some are more effective than others. The vaccine used in Nigeria was shown to be less effective, particularly in communities that are struggling with malnutrition or poor sanitation. In comparison, India began using a more effective vaccine earlier, leading to better rates of immunization. Nigeria eventually switched to the more effective vaccine, but this delay represents lost time and resources.
