PICOVAX

Indications

• Hepatitis A
• Hepatitis B
• Influenza
• Polio
• Rabies
• Typhoid fever

Dosage

Children: Refer to specific product guidelines for paediatric dosing, as it varies by vaccine type and indication.

Adults: Refer to specific product guidelines for adult dosing, as it varies by vaccine type and indication.

Mechanism of action

Inactivated vaccines work by introducing a form of the pathogen that cannot cause disease into the body. This stimulates the immune system to produce antibodies and memory cells specific to the pathogen, allowing for a robust immune response upon future exposure. The immune system recognizes the inactivated pathogen as foreign, leading to the activation of T-cells and B-cells, which are crucial for long-term immunity.

Pharmacodynamics

The pharmacodynamics of inactivated vaccines involve the generation of an adaptive immune response. After vaccination, the body produces specific antibodies against the inactivated pathogen. The response typically includes both humoral immunity, characterized by antibody production, and cellular immunity, involving T-cell activation. The duration of immunity can vary, and booster doses may be required to maintain adequate protection.

Pharmacokinetics

Inactivated vaccines do not have a pharmacokinetic profile like traditional drugs since they do not enter systemic circulation in the same manner. Following administration, the vaccine components are taken up by antigen-presenting cells, which process and present the antigens to T-cells. The immune response is initiated locally at the site of injection and can be influenced by factors such as the route of administration and the presence of adjuvants that enhance the immune response.

Adverse effects

• Injection site reactions (pain, swelling, redness)
• Fever
• Fatigue
• Headache
• Myalgia
• Chills

Precautions

• Assess for allergies to vaccine components
• Monitor for allergic reactions post-administration
• Consider underlying health conditions that may affect immune response

Pregnancy

Inactivated vaccines are generally considered safe during pregnancy, but individual risk-benefit assessment is recommended.

Breast-feeding

Inactivated vaccines can be administered during breastfeeding without concern for adverse effects in the infant.

Storage

Store in a refrigerator at 2°C to 8°C. Do not freeze.

Formulations

• Inactivated viral vaccines
• Inactivated bacterial vaccines

Indications

• Poliomyelitis prevention
• Vaccination against poliovirus
• Public health immunization programs

Dosage

Children: Refer to national immunization guidelines for childhood vaccination schedules, including IPV and OPV.

Adults: Refer to national immunization guidelines, typically involving a series of vaccinations with IPV or OPV.

Mechanism of action

Poliovirus infects host cells by binding to specific receptors on the cell surface, leading to the internalization of the virus. Once inside, poliovirus releases its RNA genome, which hijacks the host's cellular machinery to replicate and produce viral proteins. This replication can cause cell lysis and inflammation, leading to symptoms of the disease.

Pharmacodynamics

Poliovirus primarily targets motor neurons in the spinal cord and brainstem, resulting in cell death and, subsequently, muscle weakness or paralysis. The severity of the disease varies significantly, with many infections being asymptomatic, while a minority progress to paralytic disease. The immune response to the infection plays a crucial role in determining the outcome.

Pharmacokinetics

The pharmacokinetics of poliovirus is characterized by its ability to survive in the gastrointestinal tract, where it replicates before entering the bloodstream. The virus does not undergo conventional pharmacokinetic processes such as absorption, distribution, metabolism, or excretion like typical drugs, as it is a living organism. The duration of viral shedding can vary, typically lasting from a few weeks to several months, depending on the individual’s immune response.

Adverse effects

• Mild fever
• Fatigue
• Headache
• Sore throat
• Nausea
• Vomiting
• Diarrhea
• Flu-like symptoms
• Rarely, paralytic poliomyelitis

Precautions

• Monitor for signs of allergic reactions
• Patients with immunocompromised states should be assessed carefully
• Individuals should be screened for history of vaccine-associated paralytic poliomyelitis

Pregnancy

The inactivated poliovirus vaccine (IPV) is considered safe during pregnancy. Live attenuated vaccines are generally avoided.

Breast-feeding

IPV is safe for breastfeeding mothers. Live attenuated vaccines may have specific recommendations.

Storage

Store at 2 to 8 degrees Celsius. Do not freeze.

Formulations

• Inactivated poliovirus vaccine (IPV)
• Oral poliovirus vaccine (OPV)