Geneva – About 150 countries would on Sunday April 17 engage in a synchronised vaccine switch as part of a huge immunisation effort to finally push against polio.
From April 17 to May 1, these countries would engage in a synchronised switch to a bivalent or two-strain vaccine that contains no type 2 virus but targets types 1 and 3 polio.
Experts said that the vaccine, that had successfully fought polio for more than 30 years, needed to be switched for one that targeted the last few areas of risk.
According to them, with this switch, stopping transmission of the contagious viral disease that has infected millions can be possible within a year.
They said that it could also be possible for full, official, global polio eradication to be declared by the end of this decade.
Michel Zaffran ,World Health Organisation’s director of polio eradication, said, “ For the endgame in polio to succeed, a coordinated and complex vaccine switch is crucial.
“Until now, many countries have been using a shot that protects against the three types of wild polio virus – type 1, type 2 and type 3.
“But, type 2 polio transmission has been stopped since 1999, meaning that immunising against it now makes no sense.
“In rare cases it also poses a risk that the weakened type 2 virus in the vaccine can seep into circulation and cause “vaccine-derived” polio infections.’’
Zaffran, said, “It is a massive undertaking and a major step towards eradication.
“We are entering into uncharted territory; this has never been done before.
“The success will make polio only the second human disease to be eradicated since smallpox was banished in 1980.
“ There have only been 12 cases worldwide this year, in Pakistan and Afghanistan and it means the virus could spread across borders again.
“Taking our foot off the pedal now could mean polio will within a few years spread straight back into large parts of the world and create 100,000 or 200,000 cases
“The job has not been done and will not be done until we have fully eradicated the virus.”
However, Anil Dutta, a vaccine expert at British drugmaker GlaxoSmithKline, which also makes polio shots, said that eradication could span to 2019 or 2020, when all “live” oral polio vaccines need to be discontinued.
David Salisbury, an immunisation specialist and associate fellow at Britain’s Chatham House Centre on Global Health Security, said, “The last one per cent is a very long tail’ on a stubborn epidemic.
`The original date for interruption of transmission was 2000`, the next target was 2014 and it is currently 2016.
“Even with case numbers as low as they are now, 2016 may be optimistic,’’ Salisbury said.
Liam Donaldson, head of the Independent Monitoring Board of the GPEI, said, “Polio is still out there.
“It has fought back with a vengeance at every stage of the game and it is still fighting,’’ he was quoted as having told a meeting in London.
The News Agency of Nigeria reports that in Oct. 26, 2015 the World Health Organisation (WHO) had formally removed Nigeria from the list of polio-endemic countries.
The announcement had come after the historic achievement of the country in interrupting the transmission of wild poliovirus for a period of 15 months, which exceeded WHO’s target for interruption.
Only two countries, Afghanistan and Pakistan, remained polio-endemic, down from more than 125 in 1988.
Dr Matshidiso Moeti, the WHO Regional Director for Africa, who had represented The WHO Director-General, Dr Margaret Chan had said that to achieve polio eradication, we must ensure that in the next two years no child was paralysed due to polio. (Reuters/NAN)