VAXIGRIP

Indications

• Vaccination against infectious diseases
• Allergy testing and immunotherapy
• Monoclonal antibody production
• Transplantation to prevent organ rejection

Dosage

Children: Dosing of antigens in children also depends on the specific antigen and the clinical indication. For pediatric vaccinations, refer to the BNF for Children.

Adults: Dosing of antigens is highly variable and depends on the specific antigen and the clinical indication. For vaccine administration, refer to national immunization guidelines.

Mechanism of action

Antigens work by binding to specific receptors on the surface of immune cells, such as B cells and T cells. This binding triggers a cascade of immune responses, including the proliferation of specific immune cell populations and the production of antibodies that target the antigen. This process is crucial for the development of adaptive immunity, allowing the body to remember and respond more effectively to future encounters with the same antigen.

Pharmacodynamics

The pharmacodynamics of antigens involve the interaction with the immune system to elicit a response. The magnitude and quality of this response can vary based on several factors, including the nature of the antigen, the route of exposure, and the host's immune status. Antigens can be classified as T-cell dependent or T-cell independent, influencing the type of immune response generated.

Pharmacokinetics

Antigens are processed by antigen-presenting cells (APCs) that present peptide fragments to T cells. The pharmacokinetics of antigens can vary widely depending on their form (e.g., live attenuated, inactivated, or subunit vaccines). Generally, once introduced into the body, antigens are taken up by APCs, which then migrate to lymph nodes to activate T and B cells. The duration of immune response can be influenced by the type of antigen and the presence of adjuvants.

Pregnancy

Safety during pregnancy depends on the specific type of antigen. Consult relevant guidelines for specific antigens.

Breast-feeding

Safety during breastfeeding varies by antigen type. Consult relevant guidelines for specific antigens.

Storage

Store at controlled room temperature, away from light and moisture. Specific storage conditions may vary based on the type of antigen.

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

• Treatment of uncomplicated influenza in adults and children
• Post-exposure prophylaxis in individuals at high risk of influenza complications
• Prevention of influenza in populations during outbreaks

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on the drug

Adults: Refer to BNF for specific dosing recommendations based on the drug used for treatment.

Mechanism of action

The influenza virus enters host cells through endocytosis, where it releases its RNA into the cytoplasm. The viral RNA is then replicated and translated into viral proteins, which are assembled into new virions. The virus's hemagglutinin (HA) protein facilitates binding to sialic acid receptors on respiratory epithelial cells, while neuraminidase (NA) assists in the release of new viral particles from the host cell surface, allowing for the spread of infection.

Pharmacodynamics

Upon infection, the influenza virus triggers an immune response, leading to the production of pro-inflammatory cytokines and the activation of immune cells. This immune response results in the characteristic symptoms of influenza. Antiviral medications, such as neuraminidase inhibitors (e.g., oseltamivir), can reduce the severity and duration of illness by inhibiting the viral replication process.

Pharmacokinetics

The pharmacokinetics of antiviral agents used to treat influenza vary. For example, oseltamivir is rapidly absorbed after oral administration, reaching peak plasma concentrations within 1-2 hours. It is converted to its active form, oseltamivir carboxylate, primarily by hepatic metabolism. The drug is excreted mainly in urine, with a half-life of about 6-10 hours. Renal function significantly affects the clearance of oseltamivir, necessitating dose adjustments in patients with renal impairment.

Adverse effects

• Fever
• Cough
• Sore throat
• Muscle aches
• Fatigue
• Headache
• Chills
• Nasal congestion
• Gastrointestinal symptoms

Precautions

• Individuals with a history of severe allergic reactions to vaccine components should consult a healthcare professional.
• Immunocompromised patients may have a reduced response to the vaccine.
• Patients with acute febrile illness should delay vaccination until recovery.

Pregnancy

Inactivated influenza vaccines are generally considered safe during pregnancy and are recommended due to the increased risk of severe illness from influenza in pregnant individuals.

Breast-feeding

Breastfeeding individuals can receive the influenza vaccine, as it does not pose a risk to the infant and may provide passive immunity.

Storage

Store at 2-8 degrees Celsius. Do not freeze. Protect from light.

Formulations

• Inactivated influenza vaccine
• Live attenuated influenza vaccine

Dosage

Children: Refer to specific product guidelines for dosing recommendations.

Adults: Refer to specific product guidelines for dosing recommendations.

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution, as it may be excreted in breast milk and could affect the nursing infant.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Indications

• Bacterial infections
• Viral infections
• Epidemiological studies
• Antibiotic resistance monitoring

Dosage

Children: Refer to specific antimicrobial treatment guidelines based on the strain identified and the infection site.

Adults: Refer to specific antimicrobial treatment guidelines based on the strain identified and the infection site.

Mechanism of action

The mechanism of action for a strain depends on the type of microorganism it represents. For pathogenic bacteria, the strain may produce toxins, evade the host's immune response, or possess resistance mechanisms that allow it to survive in the presence of antibiotics. For viruses, strains may exhibit mutations that alter their ability to infect host cells or evade antiviral therapies.

Pharmacodynamics

Pharmacodynamics in the context of strains involves the interaction between the strain and the host's immune system, as well as the effects of specific antimicrobial agents on the strain. These interactions can influence the efficacy of treatments and the development of resistance.

Pharmacokinetics

Pharmacokinetics is not directly applicable to strains themselves but rather to the drugs used to treat infections caused by specific strains. Factors such as absorption, distribution, metabolism, and excretion of antimicrobial agents can vary depending on the strain's characteristics and the site of infection.

Pregnancy

There is limited information on the safety of strain in pregnancy. It is advisable to consult healthcare professionals for guidance.

Breast-feeding

Safety during breastfeeding is not well established. It is recommended to seek medical advice before use.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Keep out of reach of children.

Indications

• Viral infections
• Influenza
• HIV/AIDS
• Hepatitis
• Herpes simplex virus infections
• COVID-19

Dosage

Children: Paediatric dosing for antivirals is also specific to the drug and condition. Refer to established pediatric guidelines or the BNF for Children for accurate dosing.

Adults: Dosing for antiviral medications varies widely based on the specific agent and the condition being treated. Refer to specific drug guidelines for appropriate dosing information.

Mechanism of action

Virions enter host cells via various mechanisms, including receptor-mediated endocytosis or membrane fusion, depending on the type of virus. Once inside the host cell, the viral genome is released and hijacks the host's cellular machinery to replicate and produce new virions. This can lead to cell death or dysfunction, contributing to the pathophysiology of viral infections.

Pharmacodynamics

The pharmacodynamics of antiviral agents targeting virions typically involve inhibiting specific stages of the viral life cycle, such as attachment, entry, uncoating, replication, assembly, or release of virions. This can result in reduced viral load and alleviation of disease symptoms.

Pharmacokinetics

The pharmacokinetics of antiviral medications varies widely based on the specific drug being used. Absorption, distribution, metabolism, and excretion are influenced by the drug's formulation, route of administration, and the presence of food or other substances. Many antivirals have a short half-life, necessitating frequent dosing, while others may have longer duration of action.

Pregnancy

There is limited information regarding the safety of virion in pregnancy. Caution is advised, and it should be used only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

The effects of virion on breastfeeding are not well established. Caution is recommended, and it should be used only if necessary.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.