The World Health Organization (WHO) announced that Africa's largest polio immunization campaign since 2020 will begin on Friday in Cameroon, Chad, and Niger, before expanding to the Central African Republic the following week to reach a total of 21 million children.

"Africa’s largest polio vaccination campaign since 2020 kicks off today in three West and Central African countries, in a combined effort by national health authorities to immunize a total 21 million children under the age of five," WHO said in a statement.  

The initiative is powered by WHO and the Global Polio Eradication Initiative (GPEI), and it is being implemented by national health authorities in four countries in a coordinated effort to stop disease transmission.

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According to WHO, the conflict-torn Lake Chad Basin region has one of the highest proportions of unvaccinated or under-vaccinated children in the world, and despite the best efforts of local health authorities, poliovirus type 2 continues to circulate in the population.

"This is a crucial undertaking to close vaccination gaps in the wake of the COVID-19 pandemic and will provide millions of children with vital protection from the risk of irreversible polio paralysis," Matshidiso Moeti, WHO Regional Director for Africa, was quoted as saying in the statement.  

According to the statement, the new campaign aims to strengthen immunization activities by equipping community health workers to administer vaccines in homes and organizing immunization booths in schools, markets, and religious centers.

Polio is a highly contagious disease that primarily affects children under the age of five and results in paralysis or death. According to WHO, circulating poliovirus type 2 is the most common form of polio in Africa, with over 400 cases reported in 14 African countries.