The story of polio is both one of humanity’s greatest wins and a cautionary tale about public trust in science. So what are the hurdles that lie between us and reaching Adams’ dream of relegating polio to history?
The link between polio and Osama bin Laden
Conflict and political chaos has crippled vaccination efforts in Afghanistan and Pakistan, leaving them the only two countries where wild type 1 poliovirus continues to infect, paralyse and kill people.
The problem was inflamed by US efforts to hunt down terrorist leader Osama bin Laden.
In 2011, the CIA concocted a plan to confirm whether bin Laden was hiding in the Pakistan town of Abbottabad by hiring a doctor to run a fake hepatitis vaccination program, which was actually aimed at gathering the DNA of bin Laden’s children.
It’s unclear whether the operation succeeded in locating bin Laden, but a few months later Navy SEALs stormed a compound in Abbottabad and killed him.
In response, Pakistan expelled staff from Save the Children, an organisation that helped deliver real vaccination programs and knew nothing of the CIA’s ruse. Taliban militants killed scores of polio vaccination workers through shootings and suicide bombings in the wake of the operation.
Pakistan army soldiers and police officers patrol past the house, background, where it is believed al-Qaida leader Osama bin Laden lived in Abbottabad, Pakistan.Credit: AP
The saga also contributed to a deep-seated distrust of vaccination programs in the region. In an editorial, The Lancet said the saga had “a disastrous effect on worldwide eradication of infectious diseases, especially polio”.
The public health community condemned then-president Barack Obama for the plan and, in 2014, the White House said the CIA would never again use vaccination programs as a cover for espionage.
Both Afghanistan and Pakistan carried out co-ordinated polio vaccination campaigns this year, resulting in at least 11 million children dosed. It was a leap forward after more than a decade of fallout from the intelligence agency’s hijacking of public health.
Even in countries that have stamped out the wild virus, however, another challenge remains: a form of the disease that stems from the vaccine itself.
‘Alarming to Australia’: PNG’s vaccine-derived virus
In May, Papua New Guinea mounted an emergency response after a spate of polio cases struck the district of Lae. “Lae is just 500 kilometres from Cape York in Northern Queensland and hence alarming to Australia,” Jaya Dantas, a professor of international health, warned at the time.
The cases were identified as vaccine-derived polio.
Wealthy countries including Australia immunise children with a vaccine made from inactivated virus, which can’t cause disease. Low-income countries, including PNG, use a far cheaper oral vaccine that contains a weakened but live version of the virus.
Professor Raina MacIntyre writes about the history of vaccines in her book Vaccine Nation.Credit: James Brickwood
But the weakened virus passes from the guts of immunised people and into sewerage systems and waterways, where there’s a tiny but real chance of mutation into a disease-causing virus that can infect the unvaccinated. That becomes a risk if vaccine coverage isn’t up around 90 per cent. In PNG, only about 50 per cent of children are vaccinated.
“That’s where you get these outbreaks of vaccine-derived polio,” MacIntyre, head of the Kirby Institute’s biosecurity program, says. “If you’ve got high vaccination rates, it doesn’t happen.”
But why did we start using the vaccine with the live, weakened virus at all?
That goes back to the 1950s, when a new vaccine using virus deactivated with formaldehyde was approved for use. The company responsible for making the vaccine, Cutter Laboratories, committed a string of serious errors and the virus wasn’t properly inactivated during mass production of the vaccine. Children were inoculated with the live virus.
During the 1950s, as polio swept across the United States, vast iron lungs that enabled paralysed children to breathe became a powerful symbol of a greatly feared disease.Credit: Alamy Stock Photo
More than 40,000 kids caught polio, 51 were paralysed, and five died. As a result, the faulty vaccine was ditched and replaced with the oral version containing the live but weakened virus.
The Cutter incident was a disaster for public vaccine sentiment. But the prospect of catching polio and being interred within an iron lung scared people more, and immunisation efforts soon continued with different vaccines.
“This incident was the catalyst for the stringent safety systems we now have, including the testing of vaccines by the US FDA,” MacIntyre writes in her recent book Vaccine Nation. “The substandard practices in the Cutter Laboratories could not occur today.”
The Americas were polio-free by 1994.
The greater good
These chapters in the history of our fight against polio feel especially alive given Florida has just rescinded its requirement for schoolkids to get vaccinated, and anti-vax protesters prepare to march through Sydney.
In times when many seem to prioritise individual ideology over collective wellbeing, I took heart from the words of Laurie Maffly-Kipp, the niece of a woman who was infected with polio during the Cutter Laboratories disaster.
Despite her aunt having a lifelong disability due to her infection, the entire family remained avid supporters of vaccination and lined up for sugar cubes dosed with the oral vaccine once it became available.
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“My aunt was the victim of regulatory failure. Yet she saw the greater good that was at stake and chose to remain focused on that,” Maffly-Kipp wrote in US health publication STAT. “It is a tale of personal tragedy, yes, but also of a faith … in the ability of science to self-correct as it pushes toward cures for horrible diseases.
“Public health requires us to think beyond individual needs, to recognise that unless vaccines are widely distributed (and yes, even required in some cases) they will be of no use to anyone.”
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