Polio: The Disease We Almost Forgot, and the Vaccine We Still Need

Have We Forgotten What Polio Once Did to Children?

We live in a world that has almost forgotten what life was like before the discovery of polio vaccines.

There was a time when polio was one of the most feared childhood diseases. Parents watched helplessly as previously healthy children developed sudden weakness, lost the ability to walk, or struggled to breathe. For some families, the illness meant lifelong disability. For others, it meant losing a child entirely.

Today, those frightening experiences are far less common, thanks to decades of scientific research, medical advances, and widespread vaccination.

Yet something interesting has happened. As polio has become less visible, some people have begun questioning whether the disease still exists, whether the vaccine is genuinely safe, and whether children still need protection against an illness they rarely encounter.

Perhaps this is one of the greatest paradoxes of preventive medicine: when prevention works so well that a disease becomes uncommon, people may begin to question the very intervention that made it uncommon.

As we observe World Polio Day on October 24, it is worth revisiting a disease that once changed millions of lives, understanding how medical science brought it under control, and examining why vaccination remains essential.

What Exactly Is Polio?

Poliomyelitis, commonly called polio, is a highly infectious disease caused by the poliovirus. It primarily affects children under five, although unvaccinated people of any age can become infected.

The virus enters the body through the mouth and multiplies in the throat and intestines. In some individuals, it spreads to the nervous system, where it can damage motor neurons, the nerve cells responsible for controlling muscle movement.

This damage may cause muscle weakness, permanent paralysis, and, in severe cases, respiratory failure or death.

According to the Centers for Disease Control and Prevention (CDC, 2024a), most infected individuals do not experience noticeable symptoms. Unfortunately, this does not mean they cannot spread the virus.

How does polio spread?

Poliovirus spreads mainly through the faecal-oral route. This means tiny, sometimes invisible particles of infected faeces can enter another person’s mouth through contaminated hands, food, water, or objects.

Transmission through oral secretions can also occur.

Poor sanitation, inadequate handwashing, and limited access to safe drinking water increase opportunities for transmission.

However, good hygiene alone cannot replace vaccination.

The Symptoms: When an Ordinary Fever Becomes Something More Serious

Imagine a child who develops a fever, complains of tiredness and headache, and appears to have a routine viral illness.

A few days later, the child suddenly struggles to stand or move one leg.

Although most poliovirus infections do not progress this way, such a presentation illustrates why the disease can be particularly frightening.

Early symptoms may include:

• Fever and sore throat
• Headache and unusual tiredness
• Nausea, vomiting, or abdominal discomfort
• Muscle pain
• Neck or back stiffness

Some infections progress to meningitis or paralysis.

According to the CDC (2024a), approximately 1 in 200 to 1 in 2,000 poliovirus infections may result in paralysis, depending on the virus type.

Among individuals who develop paralytic polio, approximately 2–10% die, often because the muscles responsible for breathing become affected.

The majority of infected people never develop paralysis, but that should not make us underestimate the disease. An infected person without symptoms may still transmit the virus to someone who develops severe complications.

What happens to children who survive paralytic polio?

Survival does not always mean complete recovery.

Some individuals experience permanent weakness, muscle wasting, or difficulties with mobility. Others may develop post-polio syndrome decades after their original illness.

Post-polio syndrome can cause new or worsening muscle weakness, fatigue, and joint pain, sometimes 15–40 years after the initial infection.

According to the CDC, an estimated 25–40% of polio survivors may experience this condition (CDC, 2024a).

It is an important reminder that the consequences of polio can extend far beyond the original infection.

Before the Vaccine: A History We Should Never Forget

In 1952, the United States recorded more than 21,000 cases of paralytic polio.

During major outbreaks, hospitals cared for patients who had lost mobility or could no longer breathe independently. Some required mechanical respiratory support, while others faced permanent disability.

A major turning point came in 1955, when the inactivated poliovirus vaccine developed by Jonas Salk was introduced. The oral poliovirus vaccine associated with Albert Sabin followed in the early 1960s.

As vaccination expanded, polio cases declined dramatically.

The impact extended far beyond individual countries.

The World Health Organization (WHO, 2025) reports that global polio cases have fallen by more than 99% since 1988.

The CDC (2026) also estimates that vaccination has prevented approximately 20 million cases of paralysis in children since the beginning of the global eradication initiative.

A peer-reviewed modelling study by Badizadegan et al. (2022), published in The Journal of Infectious Diseases, further demonstrated the enormous number of paralytic polio cases prevented through vaccination and eradication efforts.

These numbers represent more than scientific achievement. They represent children who could walk to school, play with friends, and grow into adulthood without the devastating disability that polio might otherwise have caused.

If Vaccines Work, Why Does Polio Still Exist?

This is a reasonable question.

Vaccines have reduced polio transmission dramatically, but vaccination has not yet reached every vulnerable community.

Wild poliovirus remains endemic in Afghanistan and Pakistan. Other countries have experienced outbreaks involving circulating vaccine-derived polioviruses, particularly where vaccination coverage is inadequate.

In its August 2026 assessment, the WHO confirmed that continued poliovirus transmission and the risk of international spread remained significant public health concerns.

Importantly, a country being declared free of wild polio does not mean the virus can never return.

International travel and population movement can introduce poliovirus into communities where insufficient numbers of people are vaccinated.

Polio has been pushed back, but it has not yet been eradicated worldwide.

Are Polio Vaccines Really Safe?

For many parents, this is perhaps the most important question.

It deserves a clear, evidence-based answer, not judgment or dismissal.

Polio vaccines have been used for decades and have a strong record of preventing severe disease. However, like other medical interventions, they are not entirely free of risks.

Two major types of polio vaccines are used internationally.

1. Inactivated Poliovirus Vaccine (IPV)

IPV is administered through an injection.

It contains inactivated poliovirus, which cannot multiply or cause polio.

The vaccine stimulates the immune system to produce protective antibodies, substantially reducing the risk of paralytic disease.

Common side effects may include temporary pain, redness, or swelling at the injection site. Severe allergic reactions are rare.

IPV has been the only polio vaccine routinely used in the United States since 2000.

2. Oral Poliovirus Vaccine (OPV)

OPV is administered as drops into the mouth.

It contains weakened live poliovirus and produces important immunity in the intestines, helping reduce transmission within communities.

Because it is inexpensive, easy to administer, and effective in outbreak control, it remains an essential tool in global eradication campaigns.

However, there is an important distinction to understand.

Rarely, traditional OPV can cause vaccine-associated paralytic polio. In communities with very low vaccination coverage, weakened vaccine viruses may also circulate for prolonged periods, accumulate genetic changes, and develop into strains capable of causing outbreaks.

These are recognised risks, not reasons to dismiss vaccination altogether.

Researchers have developed newer oral vaccine formulations designed to improve genetic stability and reduce the likelihood of such outbreaks.

For example, a randomised clinical trial conducted in The Gambia and published in The Lancet found that the novel oral poliovirus vaccine type 2 (nOPV2) produced protective immune responses without identifying vaccine-related safety concerns in the trial population (Ochoge et al., 2024).

The continuing development and evaluation of vaccines demonstrate how medical science responds to safety concerns through research and improved technology.

The choice of vaccine depends on national immunisation policies, outbreak circumstances, and public health recommendations.

Why Do Children Need Multiple Doses?

Some parents wonder why their children must receive several doses of polio vaccine, particularly when they appear healthy.

The explanation lies in how the immune system develops protection.

Multiple doses help establish and strengthen immunity, making protection more reliable and longer lasting.

In the United States, the CDC recommends four doses of IPV, routinely administered at:

• 2 months
• 4 months
• 6–18 months
• 4–6 years

Schedules differ across countries, and some national programmes use both oral and injectable vaccines.

Parents should follow their national immunisation schedule and consult a healthcare professional about missed or delayed doses.

Being healthy today does not guarantee protection against tomorrow’s exposure.

Can Polio Be Treated?

There is currently no cure that reverses the nerve damage caused by paralytic polio.

Treatment focuses on supportive care, managing symptoms, and reducing complications.

Depending on the severity of the illness, patients may require physical rehabilitation, assistive devices, or respiratory support.

This is why prevention remains particularly important.

With many infectious diseases, treatment offers an opportunity to restore health after infection. With paralytic polio, some of the damage may be permanent.

Vaccination provides an opportunity to prevent that damage from occurring.

Three Questions Worth Asking This World Polio Day

Before moving on from this article, consider three simple questions.

1. If polio no longer appears common in my community, does that mean my family is completely safe?

Not necessarily. A community with low vaccination coverage may remain vulnerable to imported poliovirus.

2. If my child received one dose of polio vaccine, is that enough?

Not necessarily. Children need to complete the recommended vaccination series for reliable protection.

3. If I am uncertain about vaccine safety, where should I look for answers?

Speak with a qualified healthcare professional and consult evidence from established public health institutions and peer-reviewed medical research.

Questions about medical care are valid. The goal should be to answer them with reliable information rather than fear or misinformation.

Conclusion: Let Us Not Forget Why We No Longer Fear Polio as We Once Did

One of the greatest achievements of modern medicine is that millions of children can now grow up without experiencing diseases that once caused widespread disability and death.

Yet the absence of a disease from our everyday experiences can create a dangerous illusion that it no longer matters.

Polio did not become uncommon simply because the world became cleaner or because the virus disappeared on its own.

It became uncommon largely because scientists developed effective vaccines, healthcare workers delivered them, and generations of families participated in immunisation programmes.

As we mark World Polio Day, we should remember those who lost their lives, recognise those living with the lasting effects of polio, and acknowledge the health workers and researchers who continue working toward eradication.

Most importantly, we must protect the progress already made.

The fact that many children today have never seen someone suffer from polio is not evidence that the vaccine is unnecessary. It is evidence of what vaccination has helped humanity achieve.

Let us make sure the next generation inherits a world where polio is not merely forgotten, but truly eradicated.

References (APA 7th Edition)

Badizadegan, K., Kalkowska, D. A., & Thompson, K. M. (2022). Polio by the numbers: A global perspective. The Journal of Infectious Diseases, 226(8), 1309–1318. https://doi.org/10.1093/infdis/jiac130

Centers for Disease Control and Prevention. (2024a, May 9). About polio in the United States. https://www.cdc.gov/polio/about/

Centers for Disease Control and Prevention. (2024b, July 31). Polio vaccine safety. https://www.cdc.gov/vaccine-safety/vaccines/polio.html

Centers for Disease Control and Prevention. (2024c, July 9). Polio vaccination. https://www.cdc.gov/polio/vaccines/index.html

Centers for Disease Control and Prevention. (2026, January 30). About global polio eradication. https://www.cdc.gov/global-polio-vaccination/about/index.html

Ochoge, M., Futa, A. C., Umesi, A., et al. (2024). Safety of the novel oral poliovirus vaccine type 2 (nOPV2) in infants and young children aged 1 to less than 5 years and lot-to-lot consistency of the immune response to nOPV2 in infants in The Gambia: A phase 3, double-blind, randomised controlled trial. The Lancet, 403(10432), 1164–1175. https://doi.org/10.1016/S0140-6736(23)02844-1

World Health Organization. (2025, April 8). Poliomyelitis: Questions and answers. https://www.who.int/news-room/questions-and-answers/item/poliomyelitis

World Health Organization. (2026, August 25). Statement of the forty-fifth meeting of the Polio IHR Emergency Committee. https://www.who.int/news/item/25-08-2026-statement-of-the-forty-fifth-meeting-of-the-polio-ihr-emergency-committee

Medical disclaimer: This article is for health education and awareness and does not replace assessment, diagnosis, or treatment by a qualified healthcare professional.