Every country worldwide is now using the most effective polio vaccine
Health 10 May 2019
By Chelsea Whyte
The inactivated polio vaccine cannot be delivered orally
Mahesh Kumar A/AP/REX/Shutterstock
Mongolia and Zimbabwe have added the inactivated polio vaccine to their routine immunisation programmes. They were the last two countries in the world not to use this form of the vaccine.
Polio is a contagious viral infection that mainly affects young children and can lead to paralysis or death. It has been largely contained throughout Europe, the Americas, Southeast Asia and the Western Pacific, and cases have fallen from 350,000 in 1988 to just 33 reported cases in 2018, according to the World Health Organisation.
That decrease has predominantly been due to the oral polio vaccine, which contains a weakened form of the virus that triggers the immune system to create antibodies to fight off the disease. This form of the vaccine is effective but in rare cases it can mutate and cause vaccine-derived poliovirus.
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The inactivated polio vaccine (IPV) creates antibodies that can better enter the central nervous system and provide more protection, but must be administered through injection by a trained health worker.
Three countries have large outbreaks of wild poliovirus – Afghanistan, Pakistan and Nigeria – though Nigeria hasn't reported any cases due to wild poliovirus in 2019 yet.
Afghanistan has had 7 cases of wild poliovirus this year and Pakistan has had 11. In both countries, resistance to the vaccine is fierce and has resulted in outbreaks of violence and attacks that have led to the deaths of health workers administering it.
Pakistan's health minister Zafar Mirza said in a statement that pockets of under-immunised children are allowing the virus to survive, but it could be possible to end transmission of the disease by the end of the year.