Posted by Arlene Jorgenson on Sep 03, 2018
Today only three countries in the world continue transmitting polio. As of this date, there have been 14 Wild Polio Virus (WPV) cases (Afganistan 11, Nigeria 0, Pakistan 3). There were 22 WPV cases for the whole of last year. 
A New Threat
But there is another frightening virus on the loose in the Republic of Congo that threatens eradication progress: circulating vaccine-derived poliovirus (cVDPV). A mutation underscores the latest complication in polio eradication. It is not caused by the wild virus hanging on by a thread in these last three countries, but by a rare mutant derived from the weakened live virus in the oral polio vaccine (OPV), which has regained its neurovirulence and the ability to spread. As oral polio vaccine campaigns have driven the wild virus to near-extinction, these cVDPVs have emerged as our most significant threat to polio eradication.
This brief video explains it, in simple but clear terms.
How bad is it?
This mutated cVDPV is now causing more paralysis than the wild virus. It has been identified in 25 cases this year in Nigeria, Pakistan and Afganistan but also in Republic of Congo, Somalia, Papua New Guinea and the Syrian Republic.
How did this happen?
The oral polio vaccine consists of 3 strains of attenuated (weakened) live poliovirus. As a vaccination, these magical drops stimulate the body to produce antibodies to protect the child against polio. There is a period where the child is shedding the live polio virus through their digestive system as the vaccine does its work. If everyone in the family and community is immunized and everyone has a healthy immune system through nutrition, clean water and hygiene practices, this poses no threat. But sadly, in these lower income countries, this is not always the case. Malnutrition, dysentery, contaminated water and lack of sanitation create the environment for the live virus to continue circulating through the community. We have seen the effect of this in some children requiring upwards of 10 doses of vaccine before antibodies have developed sufficiently. One of the strains, type 2, has mutated over this extended circulation time and regained its ability to cause full-blown polio.
What has WHO done about this?
 The WHO quickly moved to create a polio vaccine with only two strains. It effectively removed the problem of the type 2 strain. By April of 2016, every country was using this new bi-valent oral polio vaccine. Then they created a mono-valent Type 2 vaccine (mOPV2) to head off any outbreaks. This mOPV2 vaccine has been released to fight outbreaks in 10 countries, and so far the strategy seems to be working, although a type 2 outbreak in Syria paralysed 74 children before coming under control last year.
What about the Congo?
The country and its international partners targeted mOPV2 campaigns to eight health districts deemed at highest risk—the minimum, experts thought, to get the maximum effect. But vaccination campaigns in the Congo, with its remote villages, crumbling infrastructure, and a weak health system, are tough. They failed to reach enough children. This cVDPV has already paralysed 29 children, and on 21 June a case was reported on the border with Uganda, far outside the known outbreak zone, heightening fears that the virus will sweep across Africa.
What does this mean?
If campaigns to immunise all children are not done quickly,  this virus could sweep across Africa and undo the progress we've made! All countries remain at risk of polio until the disease is eradicated from the world.
What is the solution?
This last push to make every country polio-free will take more money and resources than ever. There is no time to slack off. All countries must maintain strong population immunity levels through high vaccination coverage, and strong disease surveillance to rapidly detect and respond to polio.
What can you do?
We need you to continue supporting Rotary’s End Polio Now campaign. We are 'still this close'! But if we are to eradicate polio, we must meet this new challenge.
For more further reading:
Rotary End Polio report contains a great slideshow to use at your club for October 24 World Polio Day
Arlene A Jorgenson, RN
District Polio Chair
Rotary Club of Saskatoon North