Oral Polio Vaccine (OPV)

Oral Polio Vaccine (OPV) is a prescription medication belonging to the vaccine class.

Oral Polio Vaccine (OPV) is approved to prevent polio (poliomyelitis), a viral infectious disease caused by the poliovirus. It is primarily administered to infants and young children.

It is a part of national routine immunization programmes.

When OPV is administered, it replicates in the intestinal mucosa, promoting the production of antibodies. It does not go through usual metabolic processes and is eliminated in the stool, which helps the body's immune system develop.

The Oral Polio Vaccine (OPV) 's common side effects include mild fever, irritability, diarrhoea, and temporary weakness.

Oral Polio vaccine is available in oral liquid solutions (drops).

Oral Polio Vaccine (OPV) is available in India, Canada, the United States, the United Kingdom, and Australia.

Oral Polio Vaccine (OPV), belonging to the vaccine class, acts as an inactivated poliovirus.

Oral Polio Vaccine (OPV) acts via Immune response against inactivated poliovirus.

The Oral Poliovirus Vaccine (OPV) consists of inactivated forms of all three types of polioviruses (I, II, & III). It stimulates the body to generate its defence through antibodies. In case of an infection, these antibodies prevent the virus from reaching the brain, safeguarding against paralysis. This vaccine enables the immune system to confront the poliovirus with reduced threat, yet it still triggers a robust humoral response for future protection. Specifically, with OPV, the vaccine prompts a localized immune reaction in the intestinal mucous membranes, where the poliovirus replicates. Locally produced antibodies hinder the replication of subsequent infections from the wild-type poliovirus. This mechanism is pivotal in the vaccine's effectiveness against polio.

The length of disease protection is long-lasting (years), although the onset of it is relatively slow.

Oral Polio vaccine is available in oral liquid solutions (drops).

Liquid solution, oral: To be administered orally, as applicable.

Following the doctor's instructions and completing the recommended treatment course is essential. Before polio protection is fully achieved, each vaccine dosage must be received.

Oral Polio vaccine can be used as follows:

• Children who have not received the initial shot of the polio vaccination and who are visiting or residing in high-risk areas.
• Programmes to immunize large numbers of people to stop an ongoing polio epidemic.

Oral Polio vaccine can help support the following health benefits:

• Prevention: OPV provides serum immunity to all three poliovirus types, protecting against paralytic poliomyelitis. When administered, OPV triggers the production of antibodies, which provide immunity against all three poliovirus types (Type 1, Type 2, and Type 3). This immunity helps individuals resist infection and prevents the spread of the virus. It offers robust immunity against polio infection, reducing the risk of transmission within communities.
• Global Polio Eradication: OPV is an essential vaccine to eradicate polio infection globally. Countries can contribute to the worldwide goal of eradicating polio by vaccinating populations with OPV. The global incidence of polio cases has reduced significantly since the introduction of OPV. It has played a crucial role in the eradication of the wild poliovirus in numerous nations and areas.
• Herd Immunity: Herd immunity is considerably boosted by the Oral Polio Vaccine (OPV). When enough of the population receives OPV vaccination, poliovirus transmission is reduced, protecting those who cannot accept the vaccine, such as people with compromised immune systems. OPV is essential in the ongoing fight against polio because the combination of immunity lowers the possibility of outbreaks and is essential to international efforts to eradicate polio. This concept involves vaccinating a sufficient proportion of the population to halt disease transmission.

OPV vaccine is approved for its use in the following clinical indications:

• It is administered to infants and young children to provide immunity against all three types of poliovirus (type 1, type 2, and type 3).
• Indicated to adults if they have not been previously vaccinated or if they need a booster dose for specific reasons, such as travel to areas with a higher risk of polio transmission.
• OPV is used to rapidly immunize those at risk during a polio outbreak, assisting in containing the virus' transmission and preventing additional outbreaks.
• For those who work with the polio virus in a lab or another setting or for medical professionals who treat polio patients.

Orally: OPV is a liquid medication that is usually taken orally. Using a specially designed dropper, a medical professional will administer the vaccination by putting drops of the liquid into the child's mouth. The immunization schedule will determine the quantity of drops and dosages.

It is best to take the oral poliovirus vaccine at a particular time each day, whether with or without meals. Because OPV is given orally, large immunization programmes may be done efficiently and effectively.

The dosage and duration of treatment should be as per the treating physician's clinical judgment.

Liquid solution, oral: 2 mL per vial

Oral Polio vaccine is available in oral liquid solutions (drops)

Dosage Adjustment for Adult Patients

Poliovirus Prophylaxis

Unvaccinated previously: Primary series of two doses, with a 4 to 8-week interval between doses.

Completely vaccinated: Adults can receive one booster dose if travelling to polio-endemic areas or areas with high exposure risk.

Oral Polio Vaccine (OPV) should be used to prevent poliomyelitis along with no appropriate dietary restrictions. OPV usually has little effect on dietary or food substances when administered. Consuming regular foods and drinks before and after receiving the vaccine is safe.

It is commonly advised to stay hydrated by drinking water or other fluids after vaccination to reduce the risk of side effects.

The dietary restriction should be individualized as per patient requirements.

Oral Polio Vaccine (OPV) may be contraindicated in the following conditions:-

• Anaphylaxis (previous Dose of OPV or any of its components)
• Hypersensitivity to 2-phenoxyethanol, formaldehyde, neomycin, streptomycin, or polymyxin B.
• Acute febrile illness
• Immunodeficiency disorders like HIV/AIDS infection.
• Pregnancy, especially during the first trimester.
• Recent Blood or Plasma Transfusion (at least four weeks after)
• History of Guillain Barré syndrome
• Severe combined immunodeficiency (SCID) which may potentially develop vaccine-associated paralytic polio (VAPP).

The treating physician must closely monitor the patient and keep pharmacovigilance as follows.

• Those who intend to receive any live virus vaccinations, such as measles, mumps, rotavirus, smallpox, etc., must consult a healthcare professional within a month of taking OPV.
• Individuals should not get a booster shot if they have a potentially fatal adverse response to any vaccination, including live or inactivated polio virus.
• OPV should not be administered to patients receiving immunosuppressive medication (such as chemotherapy or high-dose corticosteroids) as it might not work in such cases and could increase the risk of vaccine-related complications.
• When getting OPV, individuals in close contact with those with severe immunodeficiency should exercise caution. This is due to the possibility that they unexpectedly shed the vaccination virus in their stool, possibly exposing the immunocompromised person to it.

Caution is advised when consuming alcohol with an Oral Polio Vaccine.

There is no sufficient scientific evidence traceable regarding the use and safety of Oral Polio Vaccine in the breastfeeding population.

Unsafe to use during pregnancy.

There is no sufficient scientific evidence traceable regarding the use and safety of Oral Polio vaccines in concurrent use with any particular food.

The adverse reactions related to the Oral polio vaccine can be categorized as

• Common: Low-grade fever.
• Less Common: Moderate fever, irritability and GI symptoms like nausea or diarrhoea.
• Rare: Allergic Reactions and neurological issues.

The clinically relevant drug interactions of the Oral polio vaccine are briefly summarized here:

• Immunosuppressants- Drugs like prednisone or cyclosporine suppress the immune system and may lower the effectiveness of OPV when used.
• Immunoglobulins: When administered concurrently, immunological globulins, such as intravenous immunoglobulin (IVIG), can interfere with the immunological response to OPV. The vaccination may need to be distributed more often or in greater doses for optimal outcomes.
• Antiviral Agents: Some antiviral drugs, particularly those used to treat HIV, may prevent the immunological response triggered by OPV.
• Antibiotics: OPV efficacy is typically not known to be affected by antibiotic use. However, postponing OPV delivery until the antibiotic course is over if a person is receiving antibiotics for a medical condition is usually recommended. This is so that the vaccination can provide protection, which depends on an active immune response.
• Other Vaccines: Multiple vaccinations, including OPV, given at the same time may increase the risk of adverse reactions. Medical professionals frequently adhere to vaccination regimens separated by at least four weeks to reduce such a risk, considering the time and space of vaccines.

The common side of the Oral Polio Vaccine (OPV) includes the following-

• Low or high fever
• Vomiting
• Unexpected weakness or fatigue
• Diarrhea
• Irritability

The use of Oral Polio Vaccine (OPV) should be prudent in the following group of special populations

• Pregnancy: The oral polio vaccine is unsafe to use during pregnancy since there is clear evidence that it poses a risk to the developing baby.

Pregnancy Category: X; Avoid using when pregnant. The risks exceed any potential benefits. There are safer alternatives.

• Paediatrics: Patients are given an Oral Polio Vaccine(OPV) to protect them from poliovirus infections. To protect children's health and well-being, it is an integral part of routine childhood immunization programmes.

Dosage Adjustment for Paediatric Patients

Poliovirus Prophylaxis

First Dose (Birth): The first Dose of OPV is often administered shortly after birth, ideally within the first 24 to 48 hours.

Second Dose (6 weeks): The second Dose is given at around six weeks of age. This strengthens the immunity gained from the first Dose.

Third Dose (10 weeks): The third Dose is typically administered at ten weeks of age. This further strengthens the immunological response.

Booster Doses: Additional booster doses are administered between the ages of 12 and 18 months and between 4 and 6 years. These booster vaccinations help in maintaining and strengthening immunity throughout childhood.

• Geriatrics: There is no sufficient scientific evidence traceable regarding the use and safety of the oral polio vaccine for geriatric populations.

• Lactating mothers: There is no sufficient scientific evidence traceable regarding the use and safety of oral polio vaccine for lactating mothers populations.
  

Dosage Adjustment in Kidney Impairment

There are no specific dosage adjustments provided.

Dosage Adjustment in Hepatic Impairment

There are no specific dosage adjustments provided.

The oral polio vaccine (OPV) is generally safe and effective when administered according to the established guidelines. Overdosage of OPV rarely occurs because healthcare professionals help it according to specific or precise dosing guidelines.

There is no specific antidote or treatment for excessive intake of OPV. Medical attention should be sought immediately when an overdose is suspected, followed by monitoring any adverse effects or allergic reactions. Supportive therapy should also be given, addressing any symptoms that persist or worsen. Physical treatment might be added if necessary.

Pharmacodynamics of Oral Polio Vaccine (OPV):

The Oral Polio Vaccine (OPV) has a physiological mechanism that plays a role in its pharmacodynamics. OPV stimulates the immune system to develop poliovirus-blocking antibodies. The inactivated poliovirus antigens in the vaccination cause an immunological reaction when given. Immune cells, including B cells and macrophages, recognise and process these antigens. As a result of this processing, B cells get activated and grow more numerous, producing anti-poliovirus antibodies. These antibodies serve several purposes, such as opsonization (marking the virus for destruction), neutralization (making the virus inert), and complement system activation (improving immune response). In conclusion, OPV's pharmacodynamics include producing particular antibody-mediated immunity against the poliovirus, preventing people from acquiring the disease.

Pharmacokinetics of Oral Polio Vaccine (OPV):

Absorption: Upon consumption, the vaccine viruses replicate in the digestive tract, particularly in the intestinal mucosa. Replication is necessary to trigger an immunological response.

Distribution: The intestinal mucosa, an essential site for the production of antibodies against the poliovirus, is where the replication generally takes place. The body's overall defence against the virus is helped by the immunological response produced in the digestive system.

Metabolism: Unlike drugs, OPV doesn't involve metabolism processes because vaccines contain inert viral proteins, not active drugs. The vaccine's effectiveness relies on the replication and subsequent immune response it triggers in the intestinal mucosa.

Elimination: Once metabolized or in its original form, the drug leaves the body mainly through the kidneys in the form of stool.

• Mateen, Farrah J et al. "Oral and inactivated poliovirus vaccines in the newborn: a review." Vaccine vol. 31,21 (2013): 2517-24. doi:10.1016/j.vaccine.2012.06.020
• Tang, Guihua et al. "Immunogenicity of sequential inactivated and oral poliovirus vaccines (OPV) versus inactivated poliovirus vaccine (IPV) alone in healthy infants: A systematic review and meta-analysis." Human vaccines & immunotherapeutics vol. 14,11 (2018): 2636-2643. doi:10.1080/21645515.2018.1489188
• Ciapponi, Agustín et al. "Sequential inactivated (IPV) and live oral (OPV) poliovirus vaccines for preventing poliomyelitis." The Cochrane Database of Systematic Reviews vol. 12,12 CD011260. 5 Dec. 2019, doi:10.1002/14651858.CD011260.pub2
• John, T Jacob, and Vipin M Vashishtha. "Eradicating poliomyelitis: India's journey from hyperendemic to polio-free status." The Indian Journal of Medical Research vol. 137,5 (2013): 881-94.

• Explain to the caregivers the vaccine's dosage and schedule, including information about the benefits of administration in multiple doses as part of a vaccination schedule to ensure adequate immunity against poliovirus.
• Remind the vaccine recipient, their parents, or their guardians whether they experienced any adverse reactions from a previous dose of the OPV. Also, inform them that the shot should be given annually before or during flu season.
• Assure caregivers that OPV immunizations are generally safe, with only minor, short side effects. Encouraging them to immediately report any unexpected or severe responses to the healthcare physician and, whenever applicable, to use reporting systems like the Vaccine Adverse Event Reporting System (VAERS)
• Inform caregivers of the recommended immunization schedule, which usually consists of two or three doses, depending on the vaccine brand. Also, mention the ages at which the doses should be administered and give the Vaccine Information Statements, which must be disclosed before immunization by the National Childhood Vaccine Injury Act of 1986 about the Centres for Disease Control and Prevention (CDC) website (www.cdc.gov/vaccines), these resources are freely accessible.

http://www.cdc.gov/vaccines/schedules/

https://www.indianpediatrics.net/oct2014/785 figure1.pdf

https://main.mohfw.gov.in/sites/default/files/Universal.pdf

https://www.cdc.gov/vaccines/vpd/polio/index.html