Polio in the US: All you need to know about vaccines and boosters

Thanks to the invention of an effective vaccine, and the successful vaccine campaign that followed, the United States (and most of the world) has been polio-free since 1979. So when the crippling case of polio was confirmed In a vulnerable person from New York, alarm bells sounded. New York disaster declared To increase vaccine access, health officials everywhere are reminding people to vaccinate their children against polio, a disease that can be prevented with vaccines.

On Tuesday, the US Centers for Disease Control and Prevention announce That the country is now one of 30 in the world where the vaccine-derived polio virus is spreading in a limited area, after sewage samples that detected polio in five New York counties. While the oral polio vaccine, which uses a weakened but live virus, is no longer given in the United States, other countries are still using it because it is a very fast and effective way to immunize communities against polio. But sometimes a weakened virus can mutate enough to become contagious and, in rare cases, cause severe illness in people who haven’t been vaccinated.

In societies where the vast majority of people are vaccinated, this is not usually considered a problem, says Ross Kiddle, an immunologist and professor at the University of Colorado Anschutz School of Medicine. But in communities where vaccine rates are lower than normal — such as Rockland County, where a case of polio has been reported — polio is once again becoming a problem.

“The place it causes problems is in communities where uptake of the vaccine is lower than it should be,” Kiddle said.

He added that polio is not currently a widespread threat to the United States — at least to those who have been vaccinated against it. The majority of us were fully vaccinated when they were children, which is a requirement to attend most schools. What’s more, polio vaccination has largely avoided the politicization and misinformation campaigns of other vaccines, Kiddle says, in part because the devastation, paralysis, and death the disease caused in the 1940s is still somewhat present in people’s memory. Much of this harm has been done to children.

“When you start targeting kids, people just sit back and take notice,” Kedel said.

Here’s what we know about polio vaccination, including how long immunity lasts and how few people need a polio booster right now.

A little girl receives a vaccine in the upper arm

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What types of polio vaccines are there?

There are two types of polio vaccine. The injectable inactivated vaccine is the only one that has been given in the United States since 2000, and is recommended As a series of four shots usually given before the age of six. The Centers for Disease Control recommends the first injection in two months. The oral vaccine (also called Sabin vaccine), which contains a live attenuated or weakened virus, is given by mouth.

The oral vaccine is given in other countries, and the current outbreak in New York is linked to a vaccine-derived virus that has also been discovered in the United Kingdom and Israel. in that statement This week, the Centers for Disease Control and Prevention (CDC) said these viruses are not caused by children getting the polio vaccine.

Dr. Amesh Adalja is an infectious disease physician and senior researcher at the Johns Hopkins Center for Health Security. He says the oral polio vaccine is still given in other countries because it is cheaper and easier to administer (no needles needed), but it also “provides much stronger immunity”.

“The Sabin vaccine has been in use in the United States for some time, but as the risks of polio decline, the Salk (injectable) vaccine has become the preferred one,” Adalja said in an email.

According to Kiddle, the oral polio vaccine is very effective against infection because it stops the virus from where it started: the mouth. poliomyelitis enters the body Oral, usually through hands contaminated with the feces of an infected person. This is the same reason why some researchers say a COVID-19 Nasal Vaccine It will be more effective in preventing infection, because the respiratory virus enters through the nose.

But while live polio vaccines are highly effective, they carry the risk of a return to more infectious forms.

“Polio is the illustrative example of why attenuated vaccines are so good, and why we also need to develop a more subunit or dead vaccine approach,” Kiddle said.

A child receiving oral polio vaccine

Oral polio vaccines are no longer available in the United States, but they are still a large part of other countries’ polio eradication efforts.

Ramesh Lalwani / Getty Images

How effective is the polio vaccine?

The CDC says that three doses of IPV (inactive shots currently available in the United States) are At least 99% efficacy In the prevention of paralysis caused by polio, and that the two doses are effective by 90%. Even for a vaccine that helped eradicate the disease, this sounds really high. But while the vaccines haven’t been fully tested, that efficacy holds true with Kedl.

“It is certainly one of the most successful vaccines ever made,” Kiddle said. “Not because the vaccines themselves are so high-tech and brilliant, but just because polio itself is prone to a fairly mild immune response.” This means that we may need fewer antibodies produced by the vaccine to protect us from polio than other viruses.

He noted that “polio appears very vulnerable to closure with a reasonably modest vaccine response.” “Thank God.”

Do I need another polio vaccine or booster?

With only local spread in New York, the CDC has not made any changes to vaccine recommendations for the general public at this time.

“The boosters are only recommended by the Centers for Disease Control and Prevention in special circumstances, including travel to areas where wild polio is present or where vaccine-derived strains are common,” Adalja said. “New York State has expanded that recommendation to health care workers and sanitation workers.”

New York health officials They urge everyone to start the polio series as soon as possible if they have not yet been vaccinated – including adults who have never been vaccinated, or can’t remember if they have been vaccinated. If you live anywhere in the United States and have not been vaccinated against polio, contact your doctor.

The information in this article is for educational and informational purposes only and is not intended to be health or medical advice. Always consult a physician or other qualified healthcare provider with any questions you may have about a medical condition or health goals.