Polio Vaccine - Uses, Dosage, and Side Effects

Introduction:

Poliomyelitis is a debilitating disease that results from infection with the poliovirus (p1, p2, p3).

Poliovirus is a member of the enterovirus (picornavirus) family. The virus spreads from one person to another (transmissible) by oral contact (secretions) or fecal matter of an infected individual. It can invade the nervous system (brain and spinal cord), leading to paralysis.

How Is Poliovirus Transmitted?

Poliovirus is deadly and contagious.

The mode of transmission is through the infected person’s -

• Fecal matter (stool).

• Oral secretion, droplets (sneeze or cough).

By any chance, if someone gets infected with the stool or droplet of an infected person (by touching or through hands), they can get the infection and become the carrier.

In turn, an infected person can infect others immediately (with no symptoms) and up to two weeks after the symptoms show up. The virus can survive in stool for many weeks and can contaminate food and water when touched with unwashed hands. Once viral reproduction occurs in the nasopharynx (mucosal surface), the polio virus multiplies. The multiplication increases further in the intestine.

The virus then enters the bloodstream and invades the central nervous system (brain and spinal cord). After entering the central nervous system, the virus destroys the nerve fibers and nerve cells (motor neurons) responsible for the functioning of skeletal muscles. The nerve cells can not regenerate, and the muscle loses its ability to function. This condition is known as acute flaccid paralysis (AFP). Generally, leg muscles are more affected than arm muscles. A more extensive infection may result in quadriplegia (paralysis of both legs and arms).

In severe cases (bulbar polio), poliovirus attacks the motor neurons of the brain stem resulting in diminished breathing capacity, difficulty in swallowing, and impaired speech. Bulbar polio can strike at any age but is more frequent in children (under three years of age) and may result in death.

What Are the Symptoms of Polio?

• Most people do not have any such symptoms, and many people recover without complications.

• Some people experience flu-like symptoms such as sore throat, tiredness, nausea, headache, pain, and fever. Symptoms may last for two to five days.

• In rare cases, polio can be crippling. People may suffer from weakness and paralysis of the limbs. This can last for a lifetime.

The effect on the nervous system may result in -

• Feeling of pins and needles in the legs (paresthesia).

• Infection of the outer covering of the brain and spinal cord (meningitis).

• Paralysis of limbs.

Paralysis is the most severe symptom, as it can lead to permanent disability and death.

The best way to protect yourself and the nation from this deadly virus is through vaccination.

How Serious Is Polio Infection?

• Lifelong paralysis is a serious issue associated with polio.

• Children who recover from polio can develop pain, weakness, and paralysis fifteen to forty years later.

• Children may die from polio if the virus affects the muscle that helps to breathe (bulbar polio).

How Can We Prevent Polio?

Polio can be prevented by the administration of vaccines.

Two types of vaccines are available:

• An inactivated (killed) polio vaccine (IPV) was first developed by Dr. Jonas Salk in 1955. It is given by a shot in the leg or arm (depending on age).

• An oral polio vaccine (OPV) was developed by Dr. Albert Sabin in 1961.

99 out of 100 children who take recommended doses of the polio vaccine can be protected from this crippling disease. In 1988, the World Health Assembly in Geneva resolved to eradicate the poliovirus from the world. The result is in front of us. There has been a decrease in cases of poliomyelitis by 99% to date.

What Is Inactivated Polio Vaccine (IPV)?

• The inactivated polio vaccine was developed in 1955 by Dr.Jonas Salk. It is also called the Salk vaccine.

• Inactivated (killed) polio vaccines are produced from wild-type poliovirus strains of all three poliovirus types. These strains are killed with formalin.

• It is given as a shot on the leg or arm intradermally or intramuscularly.

• It can be administered alone or in combination with other vaccines such as diphtheria, tetanus, hepatitis, etc.

• Generally, three doses are given. In most countries, a booster dose is also given.

• The inactivated polio vaccine has successfully eradicated polio cases in many countries.

• Inactivated polio vaccine provides immunity against all three types of polio.

• The efficacy of inactivated polio vaccine is more.

• Since it is not a live vaccine, no such risk is associated with the administration of inactivated polio vaccines.

What Is the Oral Polio Vaccine (OPV)?

• Oral polio vaccines are the predominant vaccines to eradicate polio.

• There are different types of oral polio vaccines available.

• Three or more doses are required to generate the desired immunity and protection.

• They are safe, effective, and less expensive.

• They are administered orally.

• No such side effects are seen.

• They are most suitable for the mass vaccination campaign.

How Efficient Are Polio Vaccines?

The Polio vaccine provides lifelong immunity but is limited to the particular type of virus involved (type one, two, three). Infection with one type of virus does not protect the prevention of infection from the other two types. Oral polio vaccines and inactivated polio vaccines are both highly effective against all three types of poliovirus. However, the safety and efficacy of both these vaccines vary.

What Is the Recommended Dose of the Polio Vaccine?

Children and Infants:

Children should get four doses of polio vaccines at the age of-

• Two months.

• Four months.

• Six to eighteen months.

• Four to six years

Children traveling to high-risk countries should receive doses before the trip.

If a child cannot complete the recommended series, an accelerated schedule has to be followed.

If the accelerated schedule can not be followed, then doses should be taken in the affected country or upon returning home.

Adults:

Most adults do not require polio vaccines as they are already vaccinated. Some adults at higher risk who should be considered for vaccination are,

• People traveling to countries at high risk of polio infection.

• Laboratory workers dealing with poliovirus.

• Healthcare workers treating polio cases.

• Unvaccinated people.

Adults who have never been vaccinated should get three doses of inactivated polio vaccine.

• First dose - at any time.

• Second dose - one to two months after the first dose.

• Third dose - six to twelve months after the second dose.

Adults who have completed all three doses and are at increased risk of exposure can receive a booster dose of inactivated polio vaccine.

Who Should Not Get Polio Vaccines?

• If the person has life-threatening allergies.

• If the person getting the vaccine is not well or has mild illnesses such as cold or fever.

What Are the Side Effects of Polio Vaccines?

• There are usually mild symptoms that go away on their own.

• Some people get a sore spot at the site where the shot was given.

• Redness, swelling, and pain are other common side effects.

• Some people faint after vaccination. Sitting or lying down for fifteen minutes post-vaccination prevents fainting.

• On rare occasions, some people may suffer from severe shoulder pain.

• The risk of severe allergies is very rare.

Conclusion:

Poliomyelitis is a crippling and life-threatening disease caused by poliovirus that may result in paralysis. To prevent poliomyelitis, polio vaccines are used. Two types of polio vaccines are there, inactivated polio vaccines (IPV) and oral polio vaccines (OPV). The former is administered intradermally or intramuscularly, while the latter is given as oral drops. Both types are efficacious and safe. To prevent the spread of poliovirus, everybody should follow the vaccination schedule and get their children vaccinated. Remember: Vaccinations are for your protection. Do not avoid them.