The world is at the brink of polio eradication. However, the World Health Organization (WHO) is concerned about the use of vaccine strains that are currently in use. After the eradication of the disease, there is a need for safer vaccines as per the WHO. One of the strains in use is a weakened vaccine strain which cannot cause the disease but can pose a danger of reverting to a virulent virus. Moreover, there have been cases where the virus has been able to survive in the guts of people with a compromised immune system and has been shed by them through feces. Hence, the WHO plans to stop using it post the eradication of the disease in favor of vaccines that use inactivated virus. However, researchers from the National Institute for Biological Standards and Control in Potters Bar, UK, have developed an attenuated strain which according to them is safer than an inactivated strain. In the Sabine vaccine strain, they edited the viral RNA to make it genetically stable. After testing it extensively in rat models, they concluded that the new strain poses a negligible threat to the human population even if it survives in any individuals. The newly developed strain would have to be assessed by an expert panel before being declared safe for use.
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