发布时间：2016-05-04 信息来源：世界卫生组织平台 点击量：30802
Eradication of polio one step closer for China, and the world
WHO/UNICEF Joint News Release
The global goal of eradicating polio is one step closer this week, as China along with 154 other countries, make the shift to a new, safer, and more immunogenic polio vaccination schedule – including an unprecedented, globally-synchronized change to ‘switch off’ a now-eradicated strand of polio virus in polio vaccines. This effort will provide better protection for children against polio, particularly those most vulnerable to infection.
“This is an important milestone in the decades-long fight against polio, and in the history of immunization globally. The notice issued by the National Health and Family Planning Commission today instructing immunization providers to stop using trivalent Oral Polio Vaccine formalizes the first, and most crucial, shift in the changed immunization schedule in China – which is great news,” said Dr Bernhard Schwartländer, WHO Representative in China.
Dr Bernhard Schwartländer
WHO Representative in China
There are three strains of wild polio virus, each of which have been used in polio vaccines given to children around the world (trivalent vaccines) – until now. One of the three strains of wild polio was declared eradicated in 2015 – which means that the eradicated strain can now be removed from polio vaccine.
This change is important because there is no longer a need to continue including the eradicated strain of virus in polio vaccine – and in fact there is now potential harm in doing so, because whenever this strain of polio is used in vaccine there is a very small risk it could come into circulation again. Hence, a new vaccine using only two strains of polio virus (bivalent vaccine) is being introduced around the world. It was critically important that the ‘switch off’ be synchronized globally – to remove any risk of the wild virus recirculating without a vaccine to protect against it.
This global vaccine ‘switch’ has been recommended by the Strategic Advisory Group of Experts on Immunization and endorsed by the World Health Assembly as a critical component of the polio endgame strategy.
"Globally, we have made remarkable progress towards eradicating polio, a crippling infectious disease. The number of cases has decreased by over 99.9% since 1988 – from an estimated 350,000 cases to fewer than 80 reported cases in 2015. Working with the Government, and with health professionals our collective goal is to protect every child from this disease – and the global vaccine switch takes us ever closer to achieving zero infections in the world,” said Ms Rana Flowers, UNICEF Representative in China.
Ms Rana Flowers
UNICEF Representative in China
The global switch is a significant step in the effort to achieve a polio-free world. In 2015, there were fewer cases reported in fewer countries than ever before. Now, the focus is on reaching every child with the polio vaccine and stopping the virus in its remaining strongholds.
In China, switching off trivalent Oral Polio Vaccine will coincide with the gradual introduction of Inactivated Polio Vaccine (IPV) into the national immunization schedule: parents will see their children receive a new polio vaccination schedule consisting of one dose of IPV, followed by 3 doses of the new two-strain (bivalent) Oral Polio Vaccine. IPV is given by injection, and the reduced OPV will be given by mouth as drops (no more sugar pills). Over time, Oral Polio Vaccine will be phased out altogether, with only IPV used.
This is also a significant change because in extremely rare cases (1 in 3 million doses), Oral Polio Vaccine, which includes live polio virus, can itself cause paralysis in children. The combined effect of reducing the number of strains of polio virus from three to two in Oral Polio Vaccine, and phasing in IPV (which cannot cause paralysis because it does not contain live virus), will greatly reduce this risk, which is already miniscule – and thus further increase the safety of this vaccine, which has been used successfully to immunize against polio for generations.
“This means the new polio immunization schedule will be safer, and provide even stronger protection against the remaining types of polio. Parents can be confident that their longtime trust in China’s immunization program is delivering dividends of a safer, polio-free world for children,” said Dr Schwartländer.
“At the end of this year’s World Immunization Week, this giant step toward getting rid of the scourge of polio serves as a reminder of the importance of immunization to the health of children. Just as smallpox was eradicated 36 years ago, we now stand on the cusp of having eliminated polio forever,” concluded Ms Flowers.