Shift in vaccine use needed to eradicate polio: WHO experts

October 23, 2015

A World Health Organization expert panel called Friday for a shift in the kinds of vaccines used to fight polio, insisting full eradication of the crippling disease is within reach.

The WHO Strategic Advisory Group of Experts (SAGE), which advises the UN health agency on immunisation policies, warned that among the biggest obstacles to eradicating were the sporadic outbreaks of the disease caused by live polio virus used in some vaccines.

"We think it's realistic that we will get polio eradicated in the next few years," SAGE chair Jon Abramson told reporters in Geneva.

After facing hundreds of thousands of cases of polio as late as the 1980s, there have so far this year been just 51 people infected with the wild form of the crippling disease that affects mainly young children.

With no cases of wild polio registered in Africa since August 2014, the wild version of the virus now exists only in Afghanistan and Pakistan.

"The problem now is that we are seeing more cases of vaccine-caused polio than we are of wild type," Abramson said.

Vaccine-derived polio infections are in rare cases caused by one type of , which contains small amounts of weakened but live polio virus.

Oral polio vaccine (OPV) replicates in the gut and can be passed to others through faecal-contaminated water, thus imperilling unvaccinated children.

Abramson said it was "a rare event to see vaccine-related paralysis," but pointed out that "when you're giving millions and millions and millions and millions of doses, you do see it."

WHO has already recommended that OPV be phased out worldwide and replaced by the inactivated polio vaccine (IPV), but due to shortages of supply the shift is taking time.

Can stop 90% of outbreaks

In the meantime, Abramson pointed out that there are two types of OPV, one that protects against all three types of the crippling disease and one that protects only against types one and three.

Since the so-called trivalent vaccine containing the type two polio virus causes the most outbreaks, SAGE is now calling on countries still using this vaccine to replace it with the bivalent version by May next year.

"What that will do is stop the vast majority of outbreaks of vaccine-related paralysis," Abramson said, acknowledging that "it won't stop all the individual cases, but it will stop somewhere near 90 percent of the outbreaks where you have multiple cases in the same area."

Hamid Jafri, director of WHO's polio eradication unit, described the SAGE recommendation as "very, very important".

He pointed out that halting the use of the trivalent OPV vaccine was particularly important in areas of conflict, where overall vaccine coverage was generally low.

"It is particularly in those areas that the vaccine is given at low coverage, which is the root of the problem, where the virus in the vaccine can begin to be transmitted and start paralysing children," he said.

Explore further: Update on global polio eradication and the polio vaccine

Related Stories

Update on global polio eradication and the polio vaccine

October 16, 2015
Shortly after the successful global Smallpox Eradication Programme (SEP) in the 80's, world leaders and public health officials announced a plan to eradicate poliomyelitis (polio) off the face of the Earth; the Pan American ...

Polio case detected in Mali, country on 'high alert': WHO

September 7, 2015
Mali is on high alert after a baby was found to have the highly contagious, crippling polio virus, the World Health Organization said Monday, blaming low vaccination coverage.

Polio cases confirmed in South Sudan, Madagascar: WHO

November 14, 2014
The World Health Organization said Friday it had confirmed unrelated cases of polio in South Sudan and in Madagascar, blaming low vaccination coverage.

WHO takes Nigeria off global list of polio-endemic countries

September 25, 2015
The World Health Organization on Friday took Nigeria off the list of polio-endemic countries, hailing a "historic achievement" more than a year after the last recorded case of the disease in Africa's most populous nation.

Ukraine reports polio outbreak, first cases in Europe since 2010: WHO (Update)

September 2, 2015
Two polio cases have been confirmed in western Ukraine, the first to be recorded in Europe since 2010, the World Health Organization (WHO) said on Wednesday.

Pakistan launches new polio vaccine, aims for 2016 wipeout

August 20, 2015
Pakistan on Thursday formally launched an injectable polio vaccine, an important step to accelerate its polio eradication campaign as the authorities vowed to wipe out the disease by 2016.

Recommended for you

Anticancer drug offers potential alternative to transplant for patients with liver failure

August 15, 2018
Patients suffering sudden liver failure could in the future benefit from a new treatment that could reduce the need for transplants, research published today shows.

Study shows how MERS coronavirus evolves to infect different species

August 14, 2018
In the past 15 years, two outbreaks of severe respiratory disease were caused by coronaviruses transmitted from animals to humans. In 2003, SARS-CoV (severe acute respiratory syndrome coronavirus) spread from civets to infect ...

Inching closer to a soft spot in isoniazid-resistant tuberculosis

August 14, 2018
Antibiotic-resistant tuberculosis is a public health threat. TB and other bacteria become resistant to antibiotics by evolving genetic changes over time, which they can do quite quickly because bacterial lifecycles are short. ...

Why do women get more migraines?

August 14, 2018
Research published today reveals a potential mechanism for migraine causation which could explain why women get more migraines than men. The study, in Frontiers in Molecular Biosciences, suggests that sex hormones affect ...

How long is an Ebola survivor contagious? One case is causing scientists to rethink the answer.

August 14, 2018
Surviving Ebola isn't like getting over the flu.

Link between common 'harmless' virus and cardiovascular damage

August 13, 2018
Researchers from Brighton and Sussex Medical School (BSMS) have found an unexpectedly close link between a herpes virus and the occurrence of immune cells damaging cardiovascular tissue.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.