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 What is the polio vaccine? Health expert explains its history and success

RFK Jr in a suit.
The lawyer for Trump health nominee Robert F. Kennedy, Jr., wants the FDA to revoke the polio vaccine. It
has basically eliminated U.S. cases but polio is not yet considered eradicated. AP Photo

Considered by public health officials to be one of the greatest success stories of recent history, the polio vaccine is currently the subject of a petition by Robert F. Kennedy Jr.’s lawyer to withdraw FDA approval for the shots.

The issue is garnering public attention because petition filer Aaron Siri is reportedly advising Kennedy, President-elect Donald Trump’s nominee to head the Department of Health and Human Services, on filling top jobs despite a history of vaccine opposition.

Northeastern Global News talked to Northeastern University public health expert Neil Maniar about how the polio vaccine works, the different types of polio vaccines, and what it will take to eradicate the disease.

Portrait of Neil Maniar.
Neil Maniar, director of Northeastern’s master of public health program, calls the polio vaccine “one of the great public health achievements of the 20th century.” Photo by Matthew Modoono/Northeastern University

The paralyzing effects of polio

Polio, short for poliomyelitis, is a highly contagious viral infection mainly affecting children under 5.

It targets nerves in the spinal cord or brain stem. One in 200 infections leads to irreversible paralysis, and of those paralyzed, 5% to 10% “die when their breathing muscles become immobilized,” according to the World Health Organization.

It can spread from person to person when someone doesn’t wash their hands after using the bathroom, or by sneezing.

In the early part of the 20th century, polio was a debilitating disease affecting hundreds of thousands in the U.S., says Maniar, director of the master of public health program at Northeastern’s Bouve College of Health Sciences.

“It was prevalent in most parts of the world, including the United States, prior to the development of the vaccine in the 1950s,” he says.

Vaccination: A high success rate

The first polio vaccine was famously developed by Dr. Jonas Salk, who used an inactivated form of the virus to practice on himself and his family before it was successfully used to immunize millions.

“Once the vaccine was developed, we saw rates drop dramatically. I don’t think there’s been a wild case of polio in the United States in at least 20 years, if not longer,” Maniar says.

“This is something that went from being a highly prevalent illness to one that is largely eradicated,” he says. “And it is because of the vaccine. It’s one of the great public health achievements of the 20th century.”

The WHO says cases of “wild” or naturally occurring polio have been reduced globally by 99% since 1988.

“Vaccines have stopped the spread of wild poliovirus in all but two countries, Afghanistan and Pakistan,” the Centers for Disease Control and Prevention says.

Different vaccines for different areas of the world

There are two different types of polio vaccines, an injectable version using an inactivated form of the virus, invented by Salk, and an oral version using a weakened live virus invented by Dr. Albert Sabin, Maniar says.

The inactivated form, IPV for inactivated polio vaccine, has been used exclusively in the U.S. since 2000, according to the CDC, which recommends that children get four shots in the arm or leg between 2 months old and age 6.

The oral version, OPV for oral polio vaccine, is given by the mouth and is used primarily in countries including African nations where low infrastructure could interfere with the schedule of shots.

“It’s much easier to administer,” Maniar says.

In rare cases that have occurred in developing nations, the oral vaccine has led to mutated variants that have caused outbreaks in unimmunized children. 

Plans to eradicate polio

The WHO warns about a possible global resurgence of the disease.

“As long as a single child remains infected, children in all countries are at risk of contracting polio,” the organization says.

Maniar says he’s concerned that efforts to undermine polio and other vaccines will result in fewer children being vaccinated — or vaccinated according to the schedule recommended by the CDC.

“If the FDA pulls (the polio vaccine), or if there are certain restrictions placed on it or it becomes something that is optional, as opposed to being required, the vaccine could become more costly or individuals may simply decide not to get it ” he says.

“Additionally, if you reduce the availability of health education programs and campaigns designed to educate the public about the safety and efficacy of vaccinations, the cumulative effect of that could be lower rates of vaccination and the potential for outbreaks of certain types of illnesses,” Maniar says.

“We live in a very connected society,” he says. “The last thing we want to see are situations where we have diseases that have been largely eradicated suddenly starting to make a comeback.”