18 July 2006 - The second of three planned National Immunization Days (NIDs) starts in Namibia today, following an outbreak of poliovirus affecting mostly adults. All the country's 2 million people will be vaccinated to protect them from any further spread of polio.

Report from a health centre dispensing polio vaccine during the first vaccination round, held in June.
Background of Namibia outbreak

Some of those waiting their turn practice receiving drops. (Credit: Tony Figueira/UNICEF)

Background*

Namibia had not had cases of polio since 1996. Currently, 185  suspect cases with sudden paralysis are under investigation, of which 17  have been reported to be  wild poliovirus. What is thought to be the first case is a 39-year old man with onset of paralysis on 8 May, later confirmed as infected with wild poliovirus type-1. Three-quarters of the  suspect cases are over 15 years old;  21 of the individuals have died. 

Genetic sequencing confirms that the virus is of Indian origin and consistent with an importation from Angola, which  was re-infected last year by a virus from India after 4 polio-free years.

The Government's immunization response consists of three NIDs, using 2.8 million doses of monovalent oral polio vaccine type 1 (mOPV1). Both the first and second NIDs are meant for the entire population of the country, rather than the usual under-five year population. 

Namibia began routine immunization for polio in 1990. While the cause of the largely adult outbreak is yet to be determined, it is likely that those who fell ill did not receive immunization as children. Routine immunization coverage within Namibia today varies by region from 60% to 80%.

* Data as of 18 July 2006, according to Ministry of Health and Social Services of Namibia.