Is Polio Coming Back? Six Things to Know

By Elizabeth Thrush on September 26, 2022

A nurse gives twins the oral polio vaccine as part of the Palestinian Ministry of Health's vaccination campaign. Photo: WHO

Polio is emerging in parts of the world that haven’t had cases in decades. What does this news mean for our collective health and for global progress toward eradicating the debilitating disease?

Malawi. Mozambique. Israel. UK. United States.

In the past year, all have detected poliovirus.

Polio cases were first reported in Malawi and Mozambique earlier this year, setting off alarm bells around the world. The wild poliovirus hadn’t been detected in either country for 30 years, and the entire African region was certified free of the wild poliovirus in 2020.

In March, Israel detected its first case of polio since 1989 in a young boy from Jerusalem.

In June, health authorities in the UK detected poliovirus in multiple wastewater samples taken in northeast London.

And then in July, the New York State Department of Health reported a polio case in an unvaccinated young man from New York. It was the first polio case recorded in the U.S. in over a decade.

In light of these developments, here are six things to know about polio right now.

What is polio?

Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. Most people infected with poliovirus will not experience any symptoms, and around 25% of people infected will experience flu-like symptoms. However, around 1 in 200 people will become paralyzed from the virus, which leads to permanent disability and can cause death. Once someone is infected with polio, there is no cure. Vaccines are the only way to prevent and stop the disease from spreading.

In Afghanistan, a volunteer vaccinator marks the left pinky finger of a girl who has just received her polio vaccine and vitamin A supplements. Photo: UNICEF/Bidel

Was the same type of polio detected in all these countries?

No. The type of poliovirus detected in Jerusalem, London, and New York is a form of poliovirus called circulating vaccine-derived poliovirus, which is not the same as the wild poliovirus detected in Malawi and Mozambique.

Wild poliovirus is the term used to describe the naturally occurring form of polio. The vaccine-derived strain of poliovirus is connected to the oral polio vaccine (OPV), which is the main vaccine used in polio eradication efforts around the world. The oral vaccine contains a weakened form of the poliovirus that induces immunity. A child vaccinated with OPV can shed the weakened virus, which can be a good thing because shedding the virus can indirectly pass on immunity to those who are unvaccinated. However, in areas with very low immunization coverage, the weakened virus can circulate for extended periods and eventually start to regain virulence and lead to a form of the virus that can cause illness and paralysis.

Due to these recent detections, Israel, the UK, and U.S. now join a list of about 30 countries that are affected by this type of polio. The only way to stop both wild and vaccine-derived poliovirus is to make sure that children everywhere are vaccinated.

"Every country remains at risk of a polio resurgence until the virus is eradicated everywhere."

How does polio return to a country after decades?

When polio vaccines were developed in the 1950s and 1960s, they led to a dramatic decrease in the spread of poliovirus, eliminating the disease in many countries. But the poliovirus is a tenacious virus and is extremely talented at finding pockets of unimmunized individuals. This tenacity has allowed the virus to continue to circulate in areas where immunization rates are low. And in the past two years, global childhood vaccination rates against polio and other diseases like measles have declined drastically largely due to impacts from the COVID-19 pandemic.

As the COVID-19 pandemic starkly reminded us, diseases can quickly jump from country to country. This means polio anywhere is a threat to people everywhere, which is why it is imperative that vaccination coverage remains high and surveillance efforts stay strong, even in countries that have not had polio cases for years. Recent discoveries of polio in countries that hadn’t detected the virus in decades is a clear warning that every country remains at risk of a polio resurgence until the virus is eradicated everywhere.

Polio vaccine bottles arranged for a photograph in Puri, India. Immunization is one of the most cost-effective public health interventions, preventing around 2 million child deaths each year worldwide. Photo: UNICEF/Singh

Do I need to get a polio booster?

If you have already been fully vaccinated against polio, you probably do not need a booster shot. In the United States, there is currently no recommendation for a polio booster shot unless you are traveling to or living in an area where the risk of getting polio is higher. If you have never been vaccinated or you missed a dose, the Centers for Disease Control and Prevention recommends that you get caught up. Those living outside of the U.S. should check the public health recommendation where they are, as different governments may handle booster recommendations differently.

Is global polio eradication possible?

Absolutely. The strategies for polio eradication work when they are fully implemented. Case in point: The disease has been successfully eliminated in most countries around the world. Since the Global Polio Eradication Initiative (GPEI) started in 1988, polio cases have dropped by 99.9%, and two of the three wild poliovirus strains have been eradicated. Despite the recent setbacks in fighting polio, we are still seeing relatively lower numbers of the disease than in previous years. We are in a unique epidemiological window where polio eradication is in sight, and the Polio Eradication Strategy 2022–2026 provides the road map to achieve this goal.

But to fully implement the plans outlined in this strategy, GPEI needs to raise $4.8 billion. The GPEI is holding a pledging moment Oct.18 at the World Health Summit in Berlin to shore up the needed resources for 2022-2026 period. Whether or not donors step up and deliver the funding it will take to wipe polio off the map for good will largely determine whether headlines about polio outbreaks become a relic of the past — or more frequent — in the years ahead.

Jean de Dieu, a UNICEF-supported vaccinator, administers the oral polio vaccine to children at the port of Kisagani in the Democratic Republic of the Congo. Photo: UNICEF/Wenga

How can I help achieve a polio-free world?

Here are three things that you can do today to help bring us closer to a world where no one will be paralyzed from polio again:

  1. Check your polio vaccination status and make sure you and your children are fully immunized. If you or your child is missing a dose, talk to your health care provider to get vaccinated as soon as possible.
  2. Encourage your political leaders to provide a financial commitment to polio eradication efforts at the World Health Summit in Berlin on Oct. 18.
  3. Donate to Rotary’s End Polio Now program, and with thanks to the Bill and Melinda Gates Foundation the impact of your donation will be tripled.

Watch: Is poliovirus making a comeback?