Disease Topics:Polio

Image result for polio dropsImage result for polio drops

Also called “trivalent oral polio vaccine” or “Sabin vaccine”, OPV consists of a mixture of live, attenuated (weakened) poliovirus strains of all three poliovirus types. The oral polio vaccine is simple to administer. A few drops, given multiple times, can protect a child for life.

Why does my baby need the polio vaccine?

The polio vaccine protects your child against polio or poliomyelitis, which is a highly infectious viral disease spread through the faeces of infected people. 

The polio virus enters through the mouth and ends up in the nervous system. It can rapidly lead to paralysis and even death. 

India has been declared a polio-free nation. However, it is still mandatory that all children under the age of five years continue to receive the polio vaccine. 

This is because polio still exists in certain other countries of the world. There is a risk of the virus getting imported into India. Hence, in view of this continuing risk, your child needs the polio vaccine

Polio mainly affects children under the age of five. Older people with lower immunity levels are also vulnerable. 

It is a common belief that polio afflicts only the lower socio-economic group. That is not true: as long as there is one infected person, all children are at risk. 

There is no cure for polio. The most effective way of preventing polio is by immunising your child with the polio vaccine at the right time. 

Older siblings who are under five years of age must also be vaccinated in case they have missed a dose.. 

Are there different forms of the polio vaccine?

There are two types of polio vaccines:

Oral polio vaccine (OPV)  
The OPV is a live but weakened form of the virus which makes the body produce antibodies against it without developing into the disease. Given as oral drops, it protects not only the person who has taken them but also others living around him. 

Once the live vaccine virus is introduced into the body, it spreads to others through the water supply, the sewage system or food and drinking water. This way an entire household, and sometimes whole communities, can get protected as the vaccine virus helps them develop antibodies against the disease. 

Inactivated polio vaccine (IPV)
The IPV, on the other hand, while highly effective, only protects the vaccinated person, and not others. It is given by injection. 


What are the symptoms of polio?

Symptoms of polio can range from mild to severe. They include:
  • headache
  • fever
  • sore throat
  • nausea
  • severe muscle pain
  • stiffness in the neck and back
As most of these symptoms are common to a viral flu, consult your doctor if your baby has any of them. In most cases, there are no symptoms. In just one per cent of the cases, the virus enters the nervous system and can cause paralysis. 

Can I give IPV to my baby when she has fever or diarrhoea?

If your child is ill at the time the IPV shot is scheduled, it is usually postponed until she recovers. The OPV, on the other hand, can be given even with fever or diarrhoea. If your baby is unwell, ask your doctor to be sure about what is best for your child. 

Check out our immunisation scheduler to find out when to give your baby the polio vaccine.


Oral polio vaccine (OPV)

The oral polio vaccine (OPV) was developed in 1961 by Albert Sabin. Also called “trivalent oral polio vaccine” or “Sabin vaccine”, OPV consists of a mixture of live, attenuated (weakened) poliovirus strains of all three poliovirus types.

Boy receiving oral polio vaccine, Kano, Nigeria
The oral polio vaccine is simple to administer. A few drops, given multiple times, can protect a child for life. 
WHO/Rod Curtis

OPV produces antibodies in the blood to all three types of poliovirus. In the event of infection, these antibodies protect against paralysis by preventing the spread of wild poliovirus to the nervous system. 

OPV also produces a local, mucosal immune response in the mucous membrane of the intestines. In the event of infection, these mucosal antibodies limit the replication of the wild poliovirus inside the intestine. This intestinal immune response to OPV is thought to be the main reason why mass campaigns with OPV can rapidly stop person-to-person transmission of wild poliovirus.


  • OPV is administered orally. It can be given by volunteers and does not require trained health workers or sterile injection equipment.
  • The vaccine is relatively inexpensive. In 2011, the cost of a single dose for public health programmes in developing countries was between 11 and 14 US cents. 
  • OPV is safe, effective, and induces long-lasting immunity to all three types of poliovirus.
  • For several weeks after vaccination, the vaccine virus replicates in the intestine, is excreted in the faeces, and can be spread to others in close contact. This means that in areas where hygiene and sanitation are poor, immunization with OPV can result in the “passive” immunization of people who have not been directly vaccinated.
  • Safety

    OPV is an extremely safe vaccine. All OPV used in supplementary immunization activities for the Global Polio Eradication Initiative is pre-qualified by WHO and procured through UNICEF. In 2006, WHO issued a statement to affirm the quality and safety of OPV.

    A vial of OPV
    Oral polio vaccine is usually provided in vials containing 10–20 doses of vaccine. A single dose is usually two drops


OPV is highly effective against all three types of wild poliovirus. When this vaccine is used however, there is competition among the three viruses to cause immunity, which results in protection but not with equal efficiency for each type: it is most effective against type 2.

One dose of OPV produces immunity to all three poliovirus serotypes in approximately 50% of recipients. Three doses produce immunity in more than 95% of recipients. Immunity is long-lasting and probably life-long.

Recommended use

In most countries, OPV remains the vaccine of choice in routine immunization schedules and supplementary immunization activities. 

Where more than one type of wild poliovirus is circulating, OPV is epidemiologically and operationally the best vaccine to use because protection develops to each of the three types of polio virus.


Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine, from where it can invade the nervous system and can cause paralysis.

Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. In a small proportion of cases, the disease causes paralysis, which is often permanent. There is no cure for polio, it can only be prevented by immunization                                                  There are three types of polio infections:

  • Sub-clinical: Approximately 95 percent of polio cases are sub-clinical, and patients may not experience any symptoms. This form of polio does not affect the central nervous system (the brain and spinal cord).
  • Non-paralytic: This form, which does affect the central nervous system, produces only mild symptoms and does not result in paralysis.
  • Paralytic: This is the rarest and most serious form of polio, which produces full or partial paralysis in the patient. There are three types of paralytic polio: spinal polio (affects the spine), bulbar polio (affects the brainstem), and bulbospinal polio (affects the spine and brainstem).

Post-polio syndrome is a complication that can occur after a person has caught and recovered from poliovirus. Symptoms of the syndrome can appear up to 35 years after the polio infection.

What Causes Polio?

Poliovirus is often transmitted from person-to-person through fecal matter. People living in areas with limited access to running water or flush toilets often get the virus from drinking water contaminated by human waste that contains the virus.

In addition, the virus can be spread by contaminated food or water or direct contact with another infected person. According to the May Clinic, the virus that causes polio is so contagious that anyone living with an infected person will likely become infected themselves. 

Pregnant women, people with weakened immune systems, such as HIV+ people, and young children are the most susceptible to the polio virus. If you have not been vaccinated, you increase your risk of contracting polio by:

  • traveling to an area that has had a recent polio outbreak
  • taking care of or living with someone infected with polio
  • handling a laboratory specimen of the virus
  • having your tonsils removed
  • extreme stress, which can compromise immune system functio

Sub-Clinical Polio

  • If patients do have symptoms, they usually last for 72 hours or less and may include:

    • headache
    • sore, red throat
    • slight fever
    • vomiting
    • general discomfort

Non-Paralytic Polio

  • The symptoms of non paralytic polio may last for a couple of days to a week or two and includes

    • fever
    • sore throat in the absence of upper respiratory infection
    • headache
    • vomiting
    • fatigue
    • abnormal reflexes
    • problems swallowing and/or breathing
    • back and neck pain and stiffness, particularly neck stiffness with forward flexion of the neck
    • arm and leg pain or stiffness
    • muscle tenderness and spasms

      Paralytic Polio

  • People with paralytic polio experience the symptoms associated with non-paralytic polio first. Soon after, the following symptoms appear:

    • loss of reflexes
    • severe spasms and muscle pain
    • loose and floppy limbs, sometimes on just one side of the body, this is due to the weakness which results from the involvement of the spine
    • sudden paralysis (temporary or permanent)
    • deformed limbs (especially the hips, ankles, and feet due to prolonged weakenss and the lack of appropriate orthopedic bracing

    Full paralysis can eventually develop, but it is rare. Only about one percent of all polio cases will result in a person being permanently paralyzed. Of those patients who experience paralysis, five to 10 percent will die when the paralysis attacks the muscles that control breathing. (CDC)

           Post-Polio Syndrome

  •    The symptoms of post-polio syndrome are:

    • continuing muscle and joint weakness
    • muscle pain that gets worse
    • becoming easily exhausted or fatigued
    • muscle wasting, also called muscle atrophy
    • trouble breathing and/or swallowing
    • sleep related breathing problems (sleep apnea)
    • becoming easily cold or
    • new onset of weakness in previously uninvolved muscles

How Do Doctors Diagnose Polio?

    • Doctors will use the patient’s reported symptoms to help determine whether he or she has polio. During a physical examination, a doctor may notice that the patient has impaired reflexes, back and neck stiffness, or difficulty lifting his or her head while lying flat.

      To definitively diagnose polio, a doctor will take a sample of the patient’s throat secretions, stool, or cerebrospinal fluid (fluid surrounding the brain and spinal cord). The sample is then tested to see if it contains poliovirus and if the cells in the cerebrospinal fluid demonstrate changes consistent with what is called aseptic meningitis (a brain infection)




There are two types of vaccine that protect against polio: inactivated poliovaccine (IPV) and oral polio vaccine (OPV). IPV is given as an injection in the leg or arm, depending on the patient's age. Polio vaccine may be given at the same time as other vaccine

How Do Doctors Treat Polio?

There is no cure for polio. Doctors can only treat the symptoms while the infection runs its course. The most common treatments include:

  • rest
  • painkillers to relieve headaches, muscle aches, and muscle spasms
  • antibiotics for urinary tract infections
  • portable ventilators to help with breathing
  • physical therapy and/or corrective braces to help with walking
  • heating pads or warm towels to ease muscle aches and spasms
  • physical therapy to treat pain in the affected muscles
  • physical therapy to address breathing and pulmonary problems and then pulmonary rehabilitation to increase the patient’s pulmonary endurance as the acute breathing problems improve
  • In advanced cases of leg weakness, when a patient has difficulty walking he or she may need a wheelchair or other mobility device
  • How to Prevent Polio

    The best way to prevent polio is to get vaccinated. Children should get polio shots according to the CDC vaccination schedule, shown below.

    Rarely, the shots can cause mild or severe allergic reactions, including:

    • breathing problems
    • high fever
    • dizziness
    • hives
    • swelling of throat
    • rapid heart rate
    • Center for Disease Control Vaccination Schedule



      2 months

      One dose

      4 months

      One dose

      6 to 18 months

      One dose

      4 to 6 years

      Booster dose



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