• To ensure that the children are adequately protected and sustain our polio-free status, polio routine immunisation will continue.
• The last case of wild poliovirus in the WHO African region was detected in Nigeria in 2016.
Kenyan children will continue to be immunised against wild polio although the highly contagious disease has been eradicated from Africa.
The decision is informed by a World Health Organisation advisory that stopping the vaccination would create a population of people susceptible to the virus, which still circulates in Pakistan and Afghanistan.
"The fact that WHO Afro region has met the threshold and is certified polio-free does not rule out re-emergence via importation of the virus in future considering that Afghanistan and Pakistan are still endemic for wild polio viruses," Health ministry head of Disease Surveillance and Epidemic Response Dr Daniel Langat told the Star.
"To ensure that the children are adequately protected and sustain our polio-free status, polio routine immunisation will continue," Langat said.
Polio, also known as poliomyelitis, is caused by a virus that attacks the nervous system.
WHO Kenya representative Rudi Eggers said the routine immunisation should be intensified.
"Kenya's immunization levels are approximately 85 per cent; however, there is need to scale this up to reach all children. Mopping up campaigns will also continue in areas with very low routine coverage or where suspected polio cases are suspected," he told the Star.
The WHO recommends an immunisation coverage of more than 95 per cent.
While no indigenous case of wild type polio has been detected in Kenya for more than a decade, vaccine derived polio viruses have been found in the country as late as 2018.
However, Kenya remained at the risk of the wild type disease importation because it was still being reported in some parts of Africa.
The continent was declared free from all the three strains of wild polio on Tuesday evening.
The certification was given by the Africa Regional Certification Commission (ARCC), an independent body comprising public health and scientific experts.
The wild poliovirus occurs naturally in three strains – type 1, type 2 and type 3.
Type 2 was declared eradicated globally in 2015, and type 3 in 2019. Only type one remains in Afghanistan and Pakistan.
The last case of wild poliovirus in the WHO African region was detected in 2016 in Nigeria.
The ARCC said its decision comes after an exhaustive, decades-long process of documentation and analysis of polio surveillance, immunisation and laboratory capacity of the region’s 47 member states, which included conducting field verification visits to each country.
The polio-free certification applies to the WHO's Africa region, which excludes North Africa. However, North Africa has not reported any case since 2004. As such, the entire continent is considered free of wild poliovirus.
“However, we must stay vigilant and keep up vaccination rates to avert a resurgence of the wild poliovirus and address the continued threat of vaccine-derived polio,” WHO regional director for Africa Matshidiso Moeti said in a statement.
Before 1996, polio paralysed an estimated 75,000 children in Africa annually.
Despite the eradication of the naturally-occurring wild virus, hundreds of people across Africa are still at risk of vaccine-derived poliovirus.
Such virus was found in sewage water during routine surveillance in Eastleigh, Nairobi, in May 2018.
It comes from the oral poliovirus vaccine (OPV), which contains weakened polioviruses.
On extremely rare occasions, the weakened virus in OPV can revert to a virulent form and cause vaccine-derived outbreaks.
However, countries prefer OPV because it is more effective as it offers community protection even in unvaccinated people.
Experts say once countries eradicate all strains of polio, they should switch to the inactivated poliovirus vaccine (IPV), which contains a dead virus.
Kenya uses both vaccines.
Eggers told the Star the country is likely to move to IPV in future.
"OPV offers community protection, so it is more preferred to IPV which only protects the vaccinated individual. But increasingly in future, we should move toward IPV," he said.
- mwaniki fm