Polio, a highly contagious viral infection that can cause paralysis and death, has been eradicated in Canada for decades thanks to widespread vaccination efforts.

However, recent comments — including from U.S. president-elect Donald Trump’s pick for health secretary, Robert F. Kennedy Jr. and his lawyer — are amplifying claims questioning the safety of vaccines for measles, mumps and rubella, as well as polio.

Both have been used safely for decades around the world by millions of people.

Aaron Siri, a lawyer advising Robert F. Kennedy Jr., in 2022 asked the Food and Drug Administration (FDA) to revoke its approval of the current polio vaccine, but the petition gained renewed attention over recent weeks after Kennedy was named as Trump’s health secretary pick.

In the petition letter, Siri urged the FDA to withdraw or suspend the polio vaccine, alleging that its original clinical trials lacked control groups and monitored long-term safety, thereby failing to meet federal safety standards

However, the polio vaccine he mentions, IPOL, has undergone extensive clinical trials, including control groups. Regulatory agencies such as the FDA have approved the vaccine based on robust evidence.

Kennedy is also a vaccine skeptic, recently saying that he may investigate vaccines he claims are linked to autism, a long-debunked theory.

His comments, along with the ongoing spread of vaccine skepticism, have sparked increased interest on Google. This surge in curiosity is reflected in the rise of breakout Google search terms, including queries like “What is polio?”, “Polio vaccine approval,” and “Does polio still exist?”.

Amid this surge in curiosity, Trump weighed in on the issue, telling reporters on Monday, “Nothing’s going to happen quickly,” when it comes to the polio vaccine.

“Bobby’s a very rational guy, you’re not going to lose the polio vaccine,” he told reporters. “I have friends that were very much affected, and they are still in not good shape because of it.”

As vaccine rhetoric from the U.S. continues to spread, Dr. Christopher Labos, a Montreal-based cardiologist and epidemiologist, fears that growing vaccine hesitancy could lead to a resurgence of polio.

“The more doubt introduced into people’s minds about the effectiveness and safety of the vaccine, the more vaccine rates start to dip. And it’s not going to take that much to bring us below the critical threshold where we start seeing more and more polio outbreaks either in the U.S. or in this country,” he said.

“If we start getting back to the days of the sustained spread of community spread of polio, we are going to see more people getting sick. We’re going to see more children paralyzed, we’re going to see deaths,” Labos added.

Polio is a highly contagious viral disease caused by the poliovirus.

It primarily affects children under the age of five but can also impact adults. The virus spreads through person-to-person contact, often via contaminated food, water, or surfaces, and it can attack the nervous system, according to the World Health Organization (WHO).

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While many people infected with the virus experience mild or no symptoms, others develop more serious complications, including permanent disability. In severe cases, polio can lead to paralysis, muscle weakness, and in some cases, death.

Throughout the early 20th century, polio outbreaks began to happen more regularly, especially in summer months, with cities seeing large numbers of cases, according to the U.S. Centers for Disease Control and Prevention (CDC). Little was known about how the disease spread, leading to closed pools in summer and empty playgrounds as parents tried to protect their children from falling ill.

And many children who contracted the disease faced severe, long-term consequences, including paralysis and the need for life-saving devices like the iron lung to assist with breathing.

But, once a widespread and devastating disease, polio has seen a 99 per cent drop in cases worldwide since 1988, thanks to the global push for vaccination and eradication efforts.

Since 1994, Canada has been free from the virus.

As of now, the poliovirus remains endemic in just two countries: Afghanistan and Pakistan.

“Until poliovirus transmission is interrupted in these countries, all countries remain at risk of importation of polio, especially vulnerable countries with weak public health and immunization services and travel or trade links to endemic countries,” according to the Global Polio Eradication Initiative.

There is no cure for polio; it can only be prevented.

The first successful vaccine was developed in the 1950s by Jonas Salk, whose inactivated polio vaccine (IPV) was introduced to the public in 1955 and became a cornerstone in the global effort to eradicate the disease.

The polio vaccine, given multiple times, can protect a child for life.

There are two types of vaccines available: the oral polio vaccine (OPV) and the IPV.

Both are safe and effective, and they are used in different combinations worldwide, depending on local epidemiological factors, to provide the best possible protection to populations, the Global Polio Eradication Initiative reports.

Polio is part of the routine vaccine schedule in Canada and is given to infants as part of a combination vaccine. It’s called DTaP-IPV-Hib-HB and protects against diphtheria, tetanus, pertussis (whooping cough), polio, Haemophilus influenzae type b (Hib) and hepatitis B.

Like the IPOL vaccine in the U.S., it is also an IPV. The vaccine is typically administered in multiple doses during the first few years of life to ensure long-lasting protection against the disease.

According to the CDC, the polio vaccine protects against severe disease caused by poliovirus in almost everyone who has received all the recommended doses. Two doses of IPV provide at least 90 per cent protection. Three doses of IPV provide at least 99 per cent protection. The most common side effect is a sore arm after the shot.

“The injected vaccine does not carry any significant side effects,”  Dr. Peter Salk, son of Jonas Salk, told Global News.

“On a very rare occasion, somebody may have an allergy to one of the components, one of the antibiotics that is used to keep things sterile. Otherwise … the medicine is really a safe vaccine,” said Salk.

Last week, U.S. Senate Republican leader Mitch McConnell, who had polio as a child, said any of president-elect Donald Trump’s nominees seeking Senate confirmation should “steer clear” of efforts to discredit the polio vaccine.

“Efforts to undermine public confidence in proven cures are not just uninformed — they’re dangerous,” McConnell said in a statement Friday.

Labos and Salk agreed.

Salk, who is a professor in the department of infectious diseases and microbiology at the University of Pittsburgh School of Public Health, explained that the public’s fear of serious diseases has diminished over time, as the terrifying effects of polio have faded from memory.

“Polio, whooping cough…these are not prevalent at this point because of vaccines. And back in the 1950s, parents were terrified of polio. Now the fear of infectious disease hasn’t been at a high pitch and people are susceptible to the notion that ‘why do want to continue to vaccinate our children? ‘”

“We want to continue to vaccinate children because diseases can come back, as it has with measles and with whooping cough,” he said.

Countries like Canada and the U.S. eliminated polio through vaccination efforts, Labos said, and abandoning these efforts could lead to the virus’s resurgence.

Even if the polio vaccine remains widely available, he said, if those in charge convince enough people not to get vaccinated, polio will make a comeback.

“I am a little bit worried because this whole anti-vaccine rhetoric has been gaining momentum in recent years, and gained legitimacy by the fact that RFK might become the head of HHS. And it is very, very problematic because we know vaccines work,” Labos said.

Cases of polio still appear in Canada due to international travel, Labos explained. People may contract the virus abroad and bring it back, where it can spread in small pockets, particularly in areas with unvaccinated individuals.

However, these outbreaks are manageable because most people are vaccinated, providing a level of protection.

He cautioned that if vaccination rates drop below a critical threshold, the population won’t have enough immunity to prevent widespread transmission, and polio could become a constant presence.

“If the number of vaccinated people starts getting lower below 80 per cent, there is a very real chance that we’re going to start to see community spread of polio again,” Labos warned.

— With files from Global News’ Amanda Connolly and the Associated Press