What is polio?

Polio, also known as poliomyelitis, is a potentially deadly disease caused by the poliovirus. It can invade an infected person’s spinal cord and brain and can lead to permanent paralysis in a matter of hours. It can also cause difficulty breathing and sometimes death.

Where is polio most common?

Although cases have decreased by 99% since 1988, the virus is still persistent in a few countries. Today, polio is endemic in just three countries:
Afghanistan
Nigeria
Pakistan

Outbreaks occur in other countries as well. Some countries still vaccinate with the live polio vaccine. This vaccine contains a weakened form of the virus that can, on a very rare occasion, mutate and cause disease. This usually occurs when a region’s population has not been adequately vaccinated. Unvaccinated individuals can then fall victim to the mutant vaccine version of the polio virus, referred to as vaccine-derived polio virus (VDPV). This is what may have happened in Rockland County, NY. Generally, a country is considered a polio risk to travelers if either “wild-type” (naturally occurring) polio or VDPV are present.

Over the past 30 years, the number of cases has decreased by 99%. In 2018, only 33 cases were reported worldwide.

How is polio transmitted?

Polio is transmitted between people through the oral and fecal-oral routes. In other words, when someone is infected, their stool and mouth/nasal secretions can transmit the virus. Therefore, contact with food and water contaminated with the virus, or direct contact with an infected patient, may result in illness.

What are the symptoms of polio?

Most people infected by poliovirus do not show symptoms (up to 70%). The virus can cause paralytic or non-paralytic polio.

What is paralytic polio?

Only a small portion of those affected by poliovirus develops more serious symptoms (approximately 1%). The symptoms of paralytic polio may initially seem like the symptoms of nonparalytic polio, such as fever and headache. Other signs and symptoms, then appear, usually within weeks:

• Severe weakness or muscle aches
• Loss of reflexes
• Flaccid paralysis (loose or floppy limbs)

Poliovirus that infects the brain and spinal cord can lead to:

• Paresthesias (feeling of pins and needles in the legs)
• Meningitis (inflammation of the tissue covering the brain)
• Paralysis
• Death

What is non-paralytic polio?

Some people infected by poliovirus contract a type of polio that does not lead to paralysis (up to 30%). The infected person develops symptoms that include the following:

• Fever
• Headache
• Sore throat
• Fatigue
• Vomiting
• Pain or stiffness in the back, neck, arms or legs
• Tenderness or weakness of the muscles

Polio Vaccine and Polio Prevention

The polio vaccine was developed and made available in 1957. The vaccine has drastically reduced the infection and helped several areas such as the Americas, Europe, Southeast Asia, and Western Pacific to be certified as polio-free.

In the United States, the polio shot we have used exclusively since 2009 is a “dead” vaccine. It is given as a series to all children and it is also recommended as a one-time adult booster to people traveling to at-risk countries.

Prevention of polio also involves proper food and water precautions, good hygiene (particularly hand washing), and avoiding contact with anyone suspected of having polio.

When Is A Polio Vaccine Required?

An adult polio booster may be required (along with written proof of immunization), even if you have already had an adult booster, if you plan to visit a polio risk country for more than four weeks (or go on specific trips, such as the hajj). The Centers for Disease Control and Prevention recommends the shot 4 weeks to 12 months before you leave the at-risk country, in this circumstance.

Why do we need a polio vaccine?

If a particular area of the US is not adequately vaccinated, it only takes one international traveler with the disease to cause a new outbreak. If our population does not remain focused on vaccinations, it is extremely likely that polio will once again become a common killer of Americans.

Does the polio vaccine last a lifetime?

Someone who received a childhood vaccination series may require a booster as an adult in times of an outbreak or travel involving high risk of exposure. If only low risk of exposure to polio exists, then the childhood series should provide lifelong immunity.

Is the adult booster really necessary?

Yes, if you are traveling to a high-risk area or during an outbreak.

Who should get a polio vaccine and when?

All children should be vaccinated with a series of four shots.

Adults who have never been vaccinated should get three doses of IPV (injectable polio vaccine). The first two doses are separated by 1-2 months and the third dose is separated by 6 months. Anyone who has had one or two doses of vaccine in the past should get the remaining one or two doses. Anyone who has had three or more doses of the vaccine only needs a booster shot (see “does the polio vaccine last a lifetime?” above).

Who shouldn’t get the polio vaccine?

Anyone who has had a life-threatening allergy to any component of the polio vaccine should not be given inoculation. If you are allergic to neomycin, streptomycin, or polymycin B it may result in a reaction and those cases should not get the vaccine. Anyone who is moderately to severely ill should wait until they are fully recovered.

What are the risks?

As with any medication, there is a risk of allergic reaction. However, the risks of a polio vaccine are very low, with the most common reaction being soreness at the injection site. Rare instances have been reported of strange behavior or high fever. Other allergic reactions may include wheezing, difficulty breathing, rashes or hives, disorientation, dizziness, or heart palpitations.

To learn more about the polio vaccine, or to receive a polio vaccination, please call and make an appointment for a consultation at Travel Medicine Consultations.

For more information, visit CDC/Polio or view the World Health Organization’s Polio Facts Sheet.