Monday October 22, 2018

Final push against Polio begins today in 150 countries

From April 17 to May 1, 150 countries will engage in a synchronized switch to a bivalent, or two-strain, vaccine that contains no type 2 virus but targets types 1 and 3

0
//
232
A girl receives polio vaccine drops at a government dispensary in a Karachi slum, Pakistan in this October 21, 2014 file photo. REUTERS/Akhtar Soomro/Files
Republish
Reprint
A girl receives a polio vaccination outside her house in Yemen's capital Sanaa in this November 9, 2015 file photo. REUTERS/Khaled Abdullah/Files
A girl receives a polio vaccination outside her house in Yemen’s capital Sanaa in this November 9, 2015 file photo. REUTERS/Khaled Abdullah/Files

By Kate Kelland

LONDON, (Reuters) – In a huge immunization effort in 150 countries, health teams will on Sunday launch what they hope will be the final push against polio.

Stopping transmission of the contagious viral disease that has infected millions is possible within a year, experts say. And full, official, global eradication could be declared by the end of this decade.

First, however, the vaccine that has successfully fought polio for more than 30 years needs to be switched for one that targets the last few areas of risk.

It won’t be easy, or cheap, but the World Health Organization’s director of polio eradication, Michel Zaffran, says failure now – when there have only been 12 cases worldwide this year, in Pakistan and Afghanistan – means the virus could spread across borders again.

Success would make polio only the second human disease to be eradicated since smallpox was banished in 1980.

“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,” Zaffran told Reuters. “The job has not been done and will not be done until we have fully eradicated the virus.”

A man suffering from polio crawls outside a row of closed shops in Siliguri, India in this December 8, 2006 file photo. REUTERS/Rupak De Chowdhuri/Files
A man suffering from polio crawls outside a row of closed shops in Siliguri, India in this December 8, 2006 file photo. REUTERS/Rupak De Chowdhuri/Files

VACCINE COMPLEXITIES

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 immunizing 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.

So from April 17 to May 1, some 150 countries will engage in a synchronized switch to a bivalent, or two-strain, vaccine that contains no type 2 virus but targets types 1 and 3.

It’s a massive undertaking and a major step towards eradication, says Zaffran. “We’re entering into uncharted territory. This has never been done before. But there’s no going back now.”

That’s partly because polio vaccine manufacturers – among them France’s Sanofi Pasteur – have moved production to the bivalent shot and would find it tricky, costly, and time-consuming to reverse that move.

Anil Dutta, a vaccine expert at British drugmaker GlaxoSmithKline, which also makes polio shots, is looking beyond eradication to 2019 or 2020, when all “live” oral polio vaccines need to be discontinued.

Then the world will switch again, to “inactivated” polio vaccine, or IPV, to further reduce any risk of causing disease through immunization. Scaling up IPV production to meet the needs of the entire world takes years, he warns, and work must start now to avoid potential supply concerns.

HISTORY OF MISSES

But prediction has never been easy in the fight to wipe out polio, and health authorities have missed targets along the way.

The Global Polio Eradication Initiative, launched in 1988, originally aimed to end all transmission of the disease by 2000.

And while there has been a 99 percent reduction in cases worldwide since the GPEI launch, fighting the last 1 percent of polio has been far tougher than expected.

In 2013, the GPEI said the global fight against polio would require $5.5 billion in funding, and more will be needed beyond that to keep a lid on the disease.

The virus, which invades the nervous system and can cause irreversible paralysis within hours, spreads rapidly among children, especially in unsanitary conditions in war-torn regions, refugee camps and areas where healthcare is limited.

In Pakistan and Afghanistan, the last two countries where polio currently remains endemic, conflict and propaganda have hampered progress, and in the past posed risks to others.

The campaign to eliminate polio in Pakistan is fraught with risk, with Islamist militants attacking health teams they accuse of being Western spies. A polio worker was shot and wounded in February and in January a suicide bomber killed 15 people outside a polio eradication center in the city of Quetta.

In 2011, a polio virus from Pakistan re-infected China, which had been polio free for more than a decade.

In 2013, the disease re-emerged in Syria after a 14-year absence, prompting the need for a vast and expensive regional emergency vaccination campaign.

And last year, cases of type 2 vaccine-derived polio posed new threats in Ukraine and Mali.

David Salisbury, an immunization specialist and associate fellow at Britain’s Chatham House Centre on Global Health Security, says the last 1 percent 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’s currently 2016,” Salisbury told Reuters, adding that even with case numbers as low as they are now, “2016 may be optimistic”.

Liam Donaldson, head of the Independent Monitoring Board of the GPEI, agrees that celebrating the expected extinction of polio virus “would not just be premature, it would be folly”.

“Polio is still out there,” he told a meeting in London. “(It) has fought back with a vengeance at every stage of the game. And it’s still fighting.”

(Reporting by Kate Kelland; editing by Giles Elgood)

Click here for reuse options!
Copyright 2016 NewsGram

Next Story

Will Polio Workers Step Out of Their Comfort Zones to End Virus?

What's more, the border between Afghanistan and Pakistan stretches for more than 2,000 kilometers. Thousands of people who cross this very porous border can easily transmit the virus in both countries.

0
Polio
Widespread unrest in Afghanistan has kept thousands of children from receiving polio vaccines this year. Conflict in northern Nigeria does the same. VOA

The move to end Polio started in 1985 with Rotary International. At that time, polio paralyzed hundreds of thousands of children every year. There is still no cure, but two scientists developed vaccines against the virus in the 1950’s.

Dr. Jonas Salk produced one with an inactivated virus that could protect against polio without spreading the disease. Later, Dr. Albert Sabin developed an oral vaccine with weakened strains of the virus.

In 1988, public and private groups joined the effort in the Global Polio Eradication Program. Members included governments, the World Health Organization, the United Nations Children’s Fund (UNICEF), Rotary International, the U.S. Centers for Disease Control and Prevention (CDC) and the Bill and Melinda Gates Foundation.

Since then, the number of polio cases has dropped by 99.9 percent. Last year, 22 children were crippled by this disease. The wild polio virus exists in only three countries: Pakistan, Afghanistan and Nigeria, but it’s still a global threat.

Dr. John Vertefeuille, from the CDC said, “This last mile is a complicated mile.” It’s not just because of conflict or terrorism. “It’s extreme remoteness. It’s very fragile health systems.” And in these remote conflict prone areas gaining access to children can be a major problem.

If polio exists anywhere, it can once again spread everywhere.

Polio
In many places the vaccinators are women because women can go into the homes, talk to other women and gain access to the children. Wikimedia

Vertefeuille and other experts discussed strategies to realize a polio-free world July 10 at the Center for Strategic and International Studies in Washington.

Widespread unrest in Afghanistan has kept thousands of children from receiving polio vaccines this year. Conflict in northern Nigeria does the same.

What’s more, the border between Afghanistan and Pakistan stretches for more than 2,000 kilometers. Thousands of people who cross this very porous border can easily transmit the virus in both countries.

While the funding and technical support has to come from large, private-public partnerships, immunization teams succeed best if they are local. Approaches have to take culture and customs into consideration.

In many places the vaccinators are women because women can go into the homes, talk to other women and gain access to the children.

Elsewhere, soldiers vaccinate children when they take over an area run by anti-government forces. Vaccination teams have to be prepared to move quickly when there is a lull in the fighting and to deliver multiple doses of vaccine in a short period of time.

Polio
Community volunteers are a great resource. Some get cell phones so they can alert health officials if a child becomes paralyzed. VOA

Surveillance is just as critical. To end polio, you have to know where the outbreaks are. Community volunteers are a great resource. Some get cell phones so they can alert health officials if a child becomes paralyzed.

Another challenge is getting children in migrant groups vaccinated. Vertefeuille says this is where technology helps. The CDC uses satellites to see where people have moved and what areas are abandoned. Clues are where structures have been repaired, where the grass grows on roads, indicating abandoned areas, and where it doesn’t, indicating where people are living.

Dr. Andrew Etsana from the International Federation of Red Cross and Red Crescent Societies said these groups present a particular challenge because “you have people moving with a virus and it is difficult to track them and vaccinate the vulnerable children in this mobile population.”

Another issue is the nature of viruses themselves. Viruses mutate. So far, the polio vaccines have been effective, but if not enough children get vaccinated, the virus can change, and perhaps make the vaccine less effective. That’s why every child needs to be vaccinated.

Outbreaks that can be avoided by vaccinating the whole population so that there are no gaps for the mutated virus to slip through.

International experts are working with local leaders to close this gap.

Another issue is complacency. Etsana said, “People are getting tired. The program has been going on. They thought it would have ended.”

Rotary has pledged to continue its support, other groups as well. International support and funding is critical to ending polio, but after three decades, many people have never seen polio. Etsana says he sees complacency creeping into all areas of the program. “The funders of the program are also getting tired. The fund is drying up and if the fund dries up and the job is not done, we’re going to have a major problem. We may have reinfection.”

Also Read-After Three Years Struggle, WHO Declares Somalia Polio Free

But, if people recognize the program’s value – it has united communities, established vaccine centers, created partnerships never before imagined – the world can not only end polio, but tackle other diseases as well. The polio program is widely credited with stopping the spread of Ebola in Nigeria while the disease ravaged other west African countries. (VOA)