Most American parents rarely think about polio after the moment their child receives the polio vaccination. However, there was a time in this country when polio paralyzed 20,000 people a year, and many of them died.
Vaccines have turned the tide against the virus. Over the past 10 years, there has only been one case in the United States related to international travel.
This situation could change rapidly if polio vaccination rates decline or vaccine availability becomes less available.
Robert F. Kennedy Jr., a longtime vaccine skeptic and potential Secretary of Health and Human Services, said the idea that vaccination has nearly eradicated polio is a “myth.”
Kennedy has said he has no intention of taking vaccines away from Americans, but he has long argued that vaccines are not as safe and effective as claimed.
As recently as 2023, a batch of an early version of the polio vaccine contaminated with the virus caused cancer and “killed far more people than any previous polio outbreak,” he said. The contamination was real, but the research Never pointed out the link to cancer.
Aaron Siri, a lawyer and adviser to Mr. Kennedy, is representing clients seeking to challenge the approval and distribution of some polio vaccines on the grounds that they may be unsafe. Ta.
These efforts are unlikely to be successful. Support for vaccination is also growing among prominent Republicans, including President-elect Donald J. Trump and Sen. Mitch McConnell, who contracted polio as a child.
But the Secretary of Health and Human Services has the authority to block vaccinations in less direct ways. He or she can withdraw federal funds Childhood immunization programalready hastening the end of school closure mandates in states. reluctant to vaccine Or exacerbate the situation by stirring up doubts about the shot. Decline in vaccination rates.
Scientists say that if polio vaccination rates decline, the virus could enter parts of the country where large numbers of unvaccinated people live and wreak havoc again. Although the virus may be nearly eradicated in its original form, a resurgence remains a threat.
Dr. David Heyman, an infectious disease physician at the London School of Hygiene and Tropical Medicine and a former polio eradication leader at the World Health Organization, said any decision the Trump administration makes on polio vaccines could have ripple effects around the world. Said it was expensive.
“If the United States takes away the license, many other countries will do the same,” he said. “It’s very, very, very, very sad that polio is coming back when we’re so close to eradicating polio,” he said.
Before the introduction of vaccines in 1955, polio disabled more than 15,000 Americans each year and hundreds of thousands more around the world. In 1952 alone, 3,000 Americans died from paralysis that made them unable to breathe.
Many of the survivors still live with the effects.
“People really underestimate how scary polio is,” says Dr. Karen Kowalske, an internist and polio specialist at the University of Texas Southwestern Medical Center in Dallas.
Many people who have recovered now suffer from “post-polio syndrome.” Some of the original symptoms return, such as muscle weakness or respiratory problems.
Dr. Kowalske treats about 100 post-polio patients who require braces, wheelchairs and other devices to cope with progressive weakness. Some older adults were infected before a vaccine was available. Others are middle-aged immigrants from countries where polio has been a problem for much longer than the United States.
For some survivors, the thought of polio returning is unfathomable.
Carol Polk contracted the disease in 1943 when she was just three years old. Her right leg never recovered, and for the rest of her life she walked with a noticeable limp and was in almost constant pain.
Polk is one of the lucky ones. Until recently, she didn’t suffer from the breathing, swallowing and digestive problems that plague polio survivors.
She has lived a “wonderful, wonderful life” with her husband and three daughters, earned a law degree and traveled abroad frequently.
But she’s always, everywhere calculating how far away the seat next to her is, how long her energy will last, and whether a certain activity is worth causing debilitating pain the next day.
She didn’t participate in the 1963 March on Washington, didn’t play the sports she wanted to, and didn’t go hiking, skiing, or biking with her husband.
If there were a hearing on the polio vaccine today, “I would go and take off the brace, show them my leg and ask them if they want that for their children,” she says. I did.
Today, even fewer children are disabled by polio. Vaccination has eliminated the virus from much of the globe, reducing the number of infections by more than 99.9 percent and preventing an estimated 20 million cases of paralysis.
Still, the virus has proven to be a stubborn enemy, and eradication has been repeatedly frustrated.
In 2024, 20 countries will report polio cases, and the virus has been detected in wastewater in five European countries, decades after polio was officially eliminated from the region. in australia.
Oliver Rosenbauer, a spokesman for the World Health Organization’s polio eradication program, said: “Polio risk goes up everywhere when health care attendance declines.”
There are three types of poliovirus, and eradication requires all three types to be eradicated. Over the years, that goal has gotten tantalizingly close.
Type 2 was declared eliminated in 2015 and type 3 in 2019. Type 1 is currently in circulation only in Afghanistan and Pakistan. In 2021, the two countries had a combined total of just five cases. In 2024, there will be 93 people.
But these numbers only tell part of the story. In a surprising development, poliovirus continues to spread long after the oral vaccines used in some parts of the world were supposed to kill it.
In most low- and middle-income countries, health authorities still rely on oral vaccines, which are administered by placing two drops on the tongue. It is cheap, easy to administer, and prevents viral infections.
However, the virus contains a weakened version of the virus that vaccinated children can shed into the environment through their feces. Once enough unvaccinated children become infected, the pathogen slowly spreads, regaining virulence and eventually causing paralysis.
The problem is that the oral vaccines used in routine immunizations since 2016 do not protect against the type 2 virus. Health authorities around the world made a deliberate decision to reformulate vaccines because the naturally occurring type 2 virus has disappeared.
It turned out to be premature. In some parts of the world, children receiving oral vaccinations were shedding more Type 2 virus than authorities expected. When children who had not been immunized or received the new oral vaccine encountered this “vaccine-derived” type 2 virus, they became infected and paralyzed.
Vaccine-derived polioviruses now paralyze more children than naturally occurring viruses. For example, Nigeria eliminated all so-called wild polio in 2020. However, in 2024, 93 people were infected with the type 2 vaccine-derived virus in the country, more than one-third of the total worldwide.
For Americans, this is no problem as long as they are vaccinated.
The inactivated polio vaccine (IPV), used for routine immunization of children in the United States, protects against all three types of polio. These preparations contain dead virus, so it cannot cause illness or revert to a dangerous form.
However, like other infectious disease vaccines, it cannot completely prevent infection and transmission of the virus. This aspect is Among the criticisms of Siri:Advisor to Mr. Kennedy.
Still, experts say it’s not as important as the vaccine’s near-perfect ability to prevent paralysis.
“Yes, yes, that’s true. IPV does not prevent infection,” said Dr. William Petri, an infectious disease physician and former chair of the WHO polio research committee. “But hey, this is the best thing since sliced bread to prevent paralysis.”
However, this means that people who receive IPV vaccinations may continue to circulate the virus, even if they themselves are protected from disease and paralysis.
Here’s a realistic scenario that worries researchers: People who receive the oral polio vaccine in other countries could bring the virus to the United States and shed it in a weakened form. This is already happening in other countries.
As long as the majority of the population continues to be vaccinated, an outbreak is unlikely. But if the virus enters areas with low vaccination rates, it can spread and revert to a virulent form that can cause paralysis.
That’s what happened in New York in 2022. An unvaccinated 20-year-old member of Rockland County’s ultra-Orthodox Jewish community contracted polio.
The county’s vaccination rate was just over 60%, compared to the national average of 93%.
The virus that paralyzed the young man has been circulating for months and has since been detected in sewage in several New York counties, where vaccination rates hover around 60%, prompting the state to take emergency action. I asked for it. declare a state of emergency.
Genetically related polioviruses have been detected in wastewater samples from the UK, Israel and Canada, suggesting widespread infection. Later, authorities discovered type 2 polioviruses derived from two different vaccines in New York sewage, suggesting the virus may have been imported in two separate batches.
If polio were to re-emerge in the United States, it is unlikely to be as dire as it was in the decades before vaccines were widely available. Many older people still remember how, as children, they were not allowed to swim in rivers, pools, or other places where the virus could harbor.
“The reason we weren’t allowed to play in the river in the 1950s was because raw sewage was being dumped into the river,” Dr Heyman said.
Because that’s no longer the case, “we’re not going to see an immediate outbreak in the U.S.,” he added.
But even if a few children became paralyzed, “it would be terrible.”
