Polio could be eradicated by end of decade

New vaccine strategies could wipe out lingering reservoirs of polio in northern India and lead to global eradication of the crippling disease by the end of the decade. Polio, is an incurable infection caused by the poliovirus leading to nerve damage and irreversible paralysis. Death occurs in about 5-10 percent of paralyzed patients when their breathing muscles are immobilized. The illness has been eliminated in developed nations but still persists in some states of India like Uttar Pradesh and Bihar and in parts of Nigeria, Afghanistan and Pakistan. Experts have now identified a simple change in the way people are vaccinated that could help wipe the disease out. Researchers from the Global Polio Eradication Initiative at the World Health Organisation (WHO) have stated that polio will not see the next decade. Other researchers from the Imperial College London said that switching to a monovalent vaccine against the dominant strain in India from the standard trivalent vaccine that protects against three types of poliovirus is the key. The virus has been so persistent because of overcrowded living conditions and poor sanitation despite good immunization coverage in northern India. Those conditions in Uttar Pradesh and Bihar made the oral poliovirus vaccine less effective than in other parts of India and immunized children were still being infected. The three strains in the trivalent vaccine can interfere with each other inside the body, producing immunity to one strain but not another. The new vaccine strategy, along with improved vaccination coverage, political will and surveillance, will help eliminate the remaining reservoirs in the four nations and achieve the goal of the Global Polio Eradication Initiative that was launched by the WHO in 1988. Since the WHO eradication drive, cases have dropped from 350,000 in more than 125 endemic countries in 1951 to about 1,500 cases so far this year - the lowest number ever. But as long as reservoirs of the virus exist, there is a danger of transmission to other countries. Twenty-five previously polio-free countries were reinfected between 2003-2005, according to the WHO. There will be a major effort in the first part of 2007, despite a $100 million funding gap, to knock out the type 1 strain of the virus, which is the most prevalent worldwide, and then a mopping up of the type 3 strain.