Back in 2022, everyone was surprised (and a little uneasy) when the news was announced that a man in New York had contracted poliovirus (polio, for short). After all, don’t all children receive the polio vaccine as part of their required, standard immunizations when they’re young? It turned out that the New York man developed vaccine-derived poliovirus, which is a strain of the weakened poliovirus that was originally included in the oral poliovirus vaccine, according to the Centers for Disease Control and Prevention (CDC), from someone who had received the oral polio vaccine. Which got everyone thinking, do adults need a polio booster?
Meet the experts: William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine; Richard Watkins, M.D., a professor of internal medicine at the Northeast Ohio Medical University; Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security.
First off, the oral polio vaccine has not been used in the United States since 2000, so transmission of this kind is incredibly rare; since then, we’ve exclusively used the inactivated poliovirus vaccine, which does not contain a live version of the virus, according to the CDC. Still, polio boosters do exist and can be beneficial for certain people. Here, infectious disease experts explain who might need a polio booster, plus what else you should know about the virus and the vaccine.
Who needs a polio booster?
Backing up a moment here: The polio vaccine is part of routine childhood vaccinations. The CDC recommends that children get four doses of polio vaccine—at 2 months old, 4 months old, 6 through 18 months old, and 4 through 6 years old. If you received these four doses as a child, you are fully vaccinated against polio, said William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine.
That said, polio boosters do exist. The CDC says that adults who are “at increased risk of exposure to poliovirus” and previously completed their poliovirus vaccination series can get one lifetime booster dose of the polio vaccine.
So, who needs a booster shot? The CDC lists off the following adults as being at an increased risk of exposure to the poliovirus and thus potentially needing a polio booster:
- People who are traveling to a country where the risk of getting polio is greater.
- People working in a laboratory and handling specimens that might contain polioviruses.
- Healthcare workers who treat patients who could have polio or have close contact with a person who could be infected with poliovirus.
“Most people do not need a polio booster because they were vaccinated against polio when they were very young,” Dr. Schaffner said. “In general, there is no polio in the U.S. and no polio in most of the world, so people don’t need a booster.”
Richard Watkins, M.D., a professor of internal medicine at the Northeast Ohio Medical University, agreed. For most people, “you get the shots as a child and then that’s it,” he said.
But, if you’re traveling to an area of the world where wild polio (the kind that caused panic and outbreaks in the 1940s) is still circulating, you may want to consider a polio booster, said Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security. According to the CDC, Afghanistan and Pakistan are the only two countries where wild poliovirus is still circulating.
How to tell if you’re vaccinated against polio
It’s probably been a minute since you received your childhood vaccinations and, since you’re not still visiting the same doctor you did as a child, you may be unsure if you were, in fact, vaccinated against polio as a child. Still, Dr. Schaffner said the odds are very high that you received your shots.
“You probably couldn’t have gone to school if you weren’t up to date,” he said. “Most schools in the U.S. have a policy of ‘no shots, no school’ when it comes to poliovirus.”
If you’re not sure where you stand, it’s OK to get a booster. “There’s no danger in getting an additional shot,” Dr. Adalja said. But, he adds, “most patient’s primary care doctors would have records for polio immunizations.”
What is polio?
Polio is a potentially disabling and life-threatening disease caused by the poliovirus, per the CDC. In some instances, the virus can infect a person’s spinal cord and cause paralysis.
Poliovirus spreads from person to person through contact with an infected person’s poop or droplets from a cough or sneeze, the CDC explains. Once a person is infected, they can spread the virus even before their symptoms appear.
Outbreaks of polio in the U.S. in the late 1940s caused more than 35,000 Americans a year to become disabled, according to Harvard Medical School. However, the country has been polio-free since 1979 thanks to a successful vaccination campaign.
What are the symptoms of polio?
Most who get infected with poliovirus won’t have visible symptoms, the CDC says, but around 25% will develop flu-like symptoms. Those can include:
- Sore throat
- Fever
- Fatigue
- Nausea
- Headache
- Stomach pain
Less than 1% of people with poliovirus will develop serious complications that impact the brain and spinal cord. Those can include:
- Paresthesia (a pins-and-needles feeling in the legs)
- Meningitis (an infection of the covering of the spinal cord and/or brain)
- Paralysis (the inability to move parts of the body)
Again, Dr. Schaffner stresses that the case of polio in New York from a few years ago is rare. “This is a very unusual event and restricted to a very conservative religious group where they are under-vaccinated,” he said. “There is no danger of spread to the general population.”