Two new ‘super-engineered’ polio vaccines have been developed by scientists to support the World Health Organisation’s mission to completely eradicate the disease. The new oral vaccines, the first new ones developed for 50 years, have been designed to stop the weakened live viruses mutating into a harmful form which can invade the nervous system, and cause paralysis.
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'With such variation in vaccination within and between countries, poliovirus has persisted into the 21st century, with sometimes tragic consequences,' said Raul Andino, professor in the Department of Microbiology and Immunology at the University of California, San Francisco; and one of the scientists behind the new vaccine. ‘We’ve designed these new vaccines using lessons learned from many years of fighting polio and believe they will help eliminate the disease once and for all.'
In the UK, and most of the developed world, an injectable form of the vaccination is used which uses a dead virus. But the oral form, more popular in less developed health systems, uses the weakened virus which only requires one mutation to revert to its original pathogenic form. The new vaccination has introduced three new mutations to lock the virus into its harmless state.
Thanks to extensive vaccination efforts, the original ‘wild’ polio virus is now thought to be eradicated in most of the world, save for a small pocket of Pakistan and Afghanistan, but vaccine-derived polio outbreaks have blighted regions where vaccination coverage has been limited by armed conflict such as the Democratic Republic of Congo and Yemen in recent years.
‘Simply having these new and better tools will not get us over the finish line,’ said Joseph Swan of the WHO and the Global Polio Eradication Initiative. ‘Vaccination, not just vaccines, is what will end polio.’
It is though that the polio virus found in London’s sewers last year was a strain derived from the oral vaccine. Following its discovery, the the Joint Committee on Vaccination and Immunisation (JCVI) offered a booster jab to children aged between 1-9 in the capital.