The WHO declares the eradication of wild polio in Africa

The WHO declares the eradication of wild polio in Africa

On Tuesday, the world celebrated a rare piece of good news from 2020: The World Health Organization announced that the wild polio virus has been eradicated from Africa.

The milestone comes after three years went by without a single case of wild polio recorded anywhere on the continent (there are still so-called vaccine-descended cases circulating, though — more on that below).

It brings us one step closer to worldwide eradication of polio; however, that achievement is still a ways away.

The eradication of a major disease is huge news, and not a common event. In the 1970s, the world came together in a concerted global campaign to eradicate smallpox, which the WHO officially certified in May 1980.

It was an enormous accomplishment, both for global public health and for the power of countries working together to solve one of the world’s greatest problems.

But it’s one we haven’t duplicated in the more than 40 years since. Efforts to eradicate diseases have run aground on both technical difficulties and political ones. In polio’s case, the disease is harder to eradicate than smallpox because in rare cases, the vaccine can give rise to a case of the disease.

Meanwhile, the cause of polio eradication was dealt a setback in the 2000s when the CIA, during the Obama administration, used a fake vaccination program as part of the effort to track down Osama bin Laden.

The WHO’s announcement Tuesday is a reminder that progress continues, albeit at a bumpy, frustrating, and sometimes disappointing pace. And although eradication of diseases may be hard, requiring global coordination on a scale it is easy to feel pessimistic about these days,

it’s achievable — and well worth the effort. Once a disease is gone from the world, we never have to devote public health resources to it again. It can never again take or change another life, allowing humanity to move on to the next target on the list.

The global fight against polio, explained

Polio is caused by a virus, usually contracted in childhood, and often results in paralysis and can lead to death.

In the early 20th century, massive outbreaks of polio devastated communities in the United States and around the world. One New York outbreak in 1916 caused 9,000 cases and 2,400 deaths, mostly of children. Terrified New Yorkers, unsure of what caused the virus, engaged in mass killings of cats and dogs believed to transmit the disease.

(They also took more sensible measures to fight the spread of a contagious virus, like shutting down schools and movie theaters.)

By the 1950s we understood polio a little better, and researcher Jonas Salk had developed a vaccine he thought would be safe and effective against the disease. In 1952, a devastating outbreak in the US saw nearly 58,000 cases and more than 3,000 deaths. The following year, the vaccine was introduced in one of the first large-scale, randomized controlled trials in history: 1.83 million American children received either the vaccine or a placebo.

The studies demonstrated that the vaccine worked. Other researchers developed a more effective vaccine that could be orally administered rather than injected, making it easier to deploy on a mass scale. The country’s outbreak was brought to a halt, and by the 1970s, the scourge of polio was nearly gone from the US. At the same time, the fight went worldwide, and through the 1980s and 1990s more and more countries drove the disease from their shores.

But there was a complication, a mild one. The oral polio vaccine has a live virus, and that virus can (very, very rarely) mutate back into a harmful form, getting the vaccinated child sick. This has been estimated to happen in about 1 in every 2.7 million cases.

And if a vaccinated person with a mutant, transmissible form of the virus is part of a community with very low vaccination rates, the mutant, transmissible virus can start circulating in the community again. This is even rarer. Since 2000, ten billion vaccine doses have been administered, and there have been 24 outbreaks of circulating vaccine-derived poliovirus.

Sufficient vaccination makes these outbreaks all but impossible, as the mutant virus does not get the chance to start circulating in the first place. But this scary side effect, though it’s exceptionally rare, has led to fears of the vaccine in a few developing countries, as has viral misinformation about other side effects and rumors that it’s a Western plot to sterilize Muslim children.

All this has made eradication more complicated. Africa’s declaration yesterday was a declaration that wild poliovirus has not been observed on the continent for three years — but the continent has still had some outbreaks of vaccine-derived poliovirus. For true eradication, we’ll need to stamp those out too. In recent years, the global eradication effort has decided to switch from the oral vaccines to the injected ones, which do not present a risk of the virus mutating.

Still paying the price of a fake vaccine campaign

The other barrier to global eradication is polio’s prevalence in rural Afghanistan and Pakistan. Vaccination efforts in those areas have not been comprehensive enough to keep a lid on the virus.

For a long time, vaccination in that region was made difficult by poverty, suspicion of aid workers, and ongoing violence. Under the Obama Administration, In 2011, the Guardian reported that the CIA had tried to confirm the location of Osama bin Laden by using a fake hepatitis vaccination campaign to get DNA samples they hoped would prove Bin Laden’s children were in a compound in Pakistan.

The effects of this deception on polio eradication efforts in the area were catastrophic. Local militants began attacking health workers delivering polio vaccines, suspecting that they were U.S. spies. International aid organizations were forced to suspend their vaccination efforts.

Polio cases spiked immediately. An article in the Lancet reported, “Release of this information has had a disastrous effect on worldwide eradication of infectious diseases, especially polio… News of the vaccination programme led to a banning of vaccination in areas controlled by the Pakistan Taliban, and added to existing scepticism surrounding the sincerity of public health efforts by the international health community. Consequently, WHO declared that polio has re-emerged as a public health emergency in Pakistan.”

The White House later stated that the US would stop using fake vaccine programs for espionage, but the damage had been done. In the next few years, at least 70 polio vaccine workers in the region were murdered. To this day, the Taliban bans vaccination, and shoots health workers who are trying to provide it. There has been no accountability for the White House’s decision to authorize a fake vaccination program for military purposes, and public trust in the region hasn’t recovered.

An embattled eradication effort still worth fighting for

This year, the ongoing battle against the poliovirus was further complicated by fears of spreading the coronavirus, which brought public health initiatives against polio in much of the world to a halt. “We did not want to have the program be responsible for worsening the situation with COVID-19,” Michel Zaffran, head of the Global Polio Eradication Initiative at the World Health Organization, said. But without vaccination, polio resurges quickly.

“The numbers look awful for eradication,” Hamid Jafari, who leads the World Health Organization’s polio eradication efforts in Pakistan and Afghanistan, said. With both wild polio and vaccine-derived polio viruses circulating, and with little immunity to the latter, affected regions could see vaccine-derived polio cases “going up to the thousands of cases, if we don’t intervene.”

In Africa, too, vaccine-derived polioviruses continue to circulate, and efforts to keep a lid on outbreaks have been damaged by coronavirus-related pauses in polio response. The milestone the WHO announced Tuesday is a real one, but in many ways this year was a setback for polio eradication.

Despite all of those challenges, there’s something important to celebrate here. A century ago, the world was ravaged by a terrifying disease we understood nothing about, which targeted mainly children and could kill them or leave them paralyzed for life. In the century since then, we learned how polio worked and how to fight it.

We embarked on a breathtakingly ambitious campaign to make sure it would never kill a child again.

And while we’re not quite there, the eradication of wild polio from the continent of Africa is a genuine cause for celebration. “It is a vivid reminder that vaccines work and that the collective actions of communities, governments and partners can bring about tremendous changes,” Dr. Matshidiso Moeti, the World Health Organization’s regional director for Africa, said in a Zoom call announcing the news.

Sometimes — despite our mistrust and suspicion, despite wrongdoing by government and violence by militants — we’re able to make the world a safer one for children. We can be proud of that, even as we’re careful not to underestimate the work ahead.

Editing in house

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