Usage
This combination of Poliomyelitis Virus Type 1, 2, and 3 is used for active immunization against poliomyelitis. It is prescribed to prevent poliomyelitis, not to treat it. This combination vaccine is categorized as an active viral vaccine. The vaccine works by inducing an immune response in the body, creating antibodies specifically targeted against all three types of the poliovirus. This provides immunity and protects against contracting poliomyelitis upon subsequent exposure to the virus.
Alternate Names
Trivalent Oral Poliovirus Vaccine (tOPV), Oral Polio Vaccine (OPV).
Some popular brands are Sabin and other brand names as per availability in different countries.
How It Works
Pharmacodynamics: The trivalent oral poliovirus vaccine (tOPV) contains live attenuated (weakened) strains of all three poliovirus serotypes. Upon administration, the viruses replicate in the intestinal tract, stimulating both humoral and intestinal mucosal immunity. This leads to the production of specific antibodies (IgG, IgA) against each poliovirus type. The immune response generated mimics that of a natural infection, but without causing the disease itself.
Pharmacokinetics: The oral route of administration ensures localized replication within the gastrointestinal tract. The viruses are not intended to be systemically absorbed. However, the immune response it elicits triggers the production of antibodies, which then circulate in the blood, providing systemic protection. The viruses in the vaccine are eventually eliminated through the digestive system.
Mechanism of Action: tOPV stimulates the production of neutralizing antibodies that bind to the poliovirus, preventing its entry into cells and thus stopping infection. It also produces localized gut immunity thanks to the production of IgA.
Dosage
Standard Dosage
Adults: Not routinely administered to adults except in special circumstances (like outbreaks) where an initial dose and subsequent boosters may be given as per national guidelines.
Children: The standard pediatric dosage schedule typically involves multiple doses, with the first dose given at around 6 weeks, followed by additional doses at intervals defined in the country specific immunization program.
Special Cases: Dose adjustments are not typically required in special patient populations like elderly, renally or hepatically impaired individuals, as tOPV administration is not routine in these groups.
Clinical Use Cases
tOPV is not used in clinical settings like intubation, surgery, ICU, or emergencies. It is solely for routine childhood immunization or for specific outbreak management.
Side Effects
Common Side Effects: Generally, tOPV is well-tolerated.
Rare but Serious Side Effects: Vaccine-Associated Paralytic Poliomyelitis (VAPP) is an extremely rare but serious adverse event.
Contraindications
Immunocompromised individuals (due to the live attenuated viruses).
Drug Interactions
No clinically significant interactions are commonly reported.
Pregnancy and Breastfeeding
Generally, tOPV is not recommended during pregnancy. Regarding breastfeeding, its use is generally avoided in the national immunization program.
Drug Profile Summary
- Mechanism of Action: Induces immunity against all three types of poliovirus by stimulating antibody production.
- Side Effects: Generally well-tolerated, VAPP (extremely rare).
- Contraindications: Immunocompromised individuals.
- Drug Interactions: Not significant.
- Pregnancy & Breastfeeding: Not recommended.
- Dosage: As per the established national/international immunization schedule.
- Monitoring Parameters: Not typically applicable for vaccines.
Popular Combinations
Often administered as part of combined childhood vaccines.
Precautions
Standard vaccination precautions apply.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Poliomyelitis Virus Type 1 + Poliomyelitis Virus Type 2 + Poliomyelitis virus type 3?
A: It is not recommended for adults except in specific circumstances, such as during an outbreak. It is primarily given to children as per the specific guidelines of national and international health organizations.
Q2: What is Vaccine-Associated Paralytic Poliomyelitis (VAPP)?
A: VAPP is an extremely rare but serious adverse event where the attenuated virus in the vaccine reverts to a neurovirulent form, potentially causing paralysis.
Q3: Can pregnant women receive tOPV?
A: tOPV is generally avoided in pregnancy, although the absolute risk is considered low. Consult the latest recommendations for specific circumstances.
Q4: Who should not receive tOPV?
A: Individuals with known immunodeficiency or who are receiving immunosuppressant medications.
Q5: Is tOPV administered to adults during an outbreak?
A: Yes, in outbreak situations, adults may receive tOPV if not previously immunized, as per national guidelines.
Q6: How effective is tOPV?
A: Highly effective in preventing poliomyelitis when administered according to the recommended schedule.
Q7: What are the different types of polio vaccines?
A: There are two main types: tOPV (Trivalent Oral Poliovirus Vaccine) which contains live attenuated virus, and IPV (Inactivated Poliovirus Vaccine) which contains inactivated (killed) virus.
Q8: How is tOPV stored?
A: tOPV requires appropriate cold chain maintenance from manufacture to administration to maintain its potency. Storage guidelines should be strictly followed as per the manufacturer’s instructions.
Q9: Can tOPV be given with other vaccines?
A: Yes, tOPV can be administered simultaneously with other routine childhood vaccines.
