Mutated Polio Virus Evades Vaccination
Polio is considered nearly eradicated worldwide, however, new disturbing research shows that a mutated virus was able to resist the vaccine protection, potentially leading to future outbreaks.
Researchers from Universität Bonn report that this mutated strain is behind an outbreak in the Congo in 2010 - which led to 209 deaths - and possibly infected people in Germany as well. What's important, researchers stress, is that many of those affected had apparently been vaccinated, based on surveyed participants. Until now, the vaccination had been considered a highly effective weapon for containing the polioviruses that cause the disease.
"We isolated polio-viruses from the deceased and examined the viruses more closely," study leader Dr. Jan Felix Drexler explained in a university press release. "The pathogen carries a mutation that changes its form at a decisive point."
Thanks to global efforts to eradicate the disease, since 1988 polio cases have decreased by over 99 percent, from an estimated 350,000 cases then, to 406 reported cases in 2013, according to the World Health Organization (WHO). In 2014, only three countries - Afghanistan, Nigeria and Pakistan - remain polio-endemic, and it was recently announced that the disease has been fully eradicated in India, with the last case of polio reported in 2011.
However, with a new mutated virus floating around out there, there is a threat to all previous hard work done to eliminate this disease completely.
Researchers behind the study decided to examine the new pathogen and determine how successful it is at bypassing our body's immune system. They tested blood samples from 34 medical students of the University of Bonn, all who were vaccinated as children. Initial results showed that the antibodies in the blood of the test subjects had no problem combating "normal" polio viruses. However, with the mutated virus, the immune reaction was much weaker.
"We estimate that one in five of our Bonn test subjects could have been infected by the new polio virus, perhaps even one in three," added researcher Christian Drosten.
The WHO has undertaken the goal of eradicating the polio virus in coming years, Nature World News previously reported. And even though officials were able to stop the polio epidemic in the Congo with a massive vaccination program, this new mutated pathogen serves as a warning, researchers say, that the fight against the disease is not over.
"We need to further increase the vaccination rate and develop new, more potent vaccines," the scientists warn in their report, published in the journal PNAS. "Only in this way do we have a chance of permanently vanquishing polio."
Polio mainly affects children under the age of 5, and is spread via person-to-person contact, the WHO reports. Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs.