OPV Mutation
If you've previously taken a look at the polio insert or received a polio vaccine for yourself or child, you will have noticed the vaccine was IPV, not OPV.
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IPV stands for inactivated polio vaccine, while OPV is oral polio vaccine. In the US, we don't use the OPV anymore.. for this very reason as stated in the insert
" Of the 127 cases of paralytic poliomyelitis reported in the US 8 between 1980 and 1994, six were imported cases (caused by wild polioviruses), two were 9 “indeterminate” cases, and 119 were vaccine associated paralytic poliomyelitis (VAPP) cases 10 associated with the use of live, attenuated oral poliovirus vaccine (OPV). "
It then follows saying
"An all IPV schedule 11 was adopted in 1999 to eliminate VAPP cases. "
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Now it was a great move to switch from the OPV to the IPV, unfortunately it is still being used in other parts of the world. The OPV is a live vaccine, so like other live vaccines it is excreted from the body after vaccination. Here are some examples:
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https://www.nationalgeographic.com/science/phenomena/2015/09/02/polio-28-years/
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When it's left the body, it goes into the environment. In this case, its allowing the polio virus to mutate, creating VDPVs (vaccine derived polioviruses). In areas lacking adequate sanitation according to the WHO, the longer the virus survives, the more genetic changes are possible resulting in the mutated strain were presently seeing. From 2000-2017, there were 24 VDPV outbreaks in 21 countries, resulting in between 520 - 780 cases.
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