When a rumour surfaced in 2003 that Nigeria's polio vaccine was possibly being contaminated with anti-fertility agents a boycott of the vaccine ensued and the country's polio immunisation campaign was dealt a heavy blow.
The boycott lasted for nearly 15 months - from February 2003 to July 2004 - and it had devastating consequences. The polio caseload shot up. And by 2008, Nigeria alone accounted for 86% of all the polio cases on the continent. Since the boycott the country has struggled to be declared polio free.
The country's polio immunisation campaign, and its entire routine immunisation programme, face another possible setback. A round of rumours has been circulating that people dressed in Army uniforms were forcefully vaccinating primary and secondary school children and injecting them with unknown diseases. Social media was flooded with rumours that the campaign is a ploy to infect the children of the region with the Monkey Pox Virus aimed to wipe out the people of the region. The rumours caused massive panic and even led to the closure of schools in the south east and north east of Nigeria as parents have rushed to take their children home.
The military exercise was started in September last year and the rumours came at a time when the Nigerian Army was conducting Special Security and Training Exercise, code-named Crocodile Smile 2' for the South-South and South West zones of Nigeria.
The Nigerian government dismissed the social media reports, declaring that only the federal, state and local government health agencies are authorised to administer vaccines to pupils nationwide.
Nigeria is still not polio free. In 2014, it came close, after being removed from the list of polio endemic countries in the world. But new cases have since emerged and it remains the only country in Africa and one of three in the world (the others being Afghanistan and Pakistan) that has not eradicated polio.
Worringly the boycott may have led to a transmission of the virus to other countries. Cases of the virus genetically linked to those originating in Nigeria have been found in Yemen and Indonesia which had already eliminated the disease.
Nigerian health authorities are concerned that in addition to affecting the polio campaign, the rumours could affect routine immunisation in general. The worst case scenario would be that diseases that should have been eliminated could continue to be transmitted.
Why the rumours stuck
The rumours that caused the 2003 polio vaccine boycott in northern Nigeria were fuelled and festered by a combination of factors and circumstances.