ERVEBO (EBOLA ZAIRE VACCINE(rVSV∆G-ZEBOV-GP1,2 LIVE, ATTENUATED) SOLUTION FOR INJECTION

Indications

• Measles
• Mumps
• Rubella
• Yellow fever
• Varicella (chickenpox)
• Rotavirus

Dosage

Children: Refer to specific vaccine guidelines for paediatric dosing.

Adults: Refer to specific vaccine guidelines for adult dosing.

Mechanism of action

Attenuated vaccines work by mimicking a natural infection. The weakened pathogen replicates in the body, stimulating the immune system to produce a response against it, which includes the activation of T-cells and the production of antibodies. This prepares the immune system to recognize and fight off the pathogen if exposed in the future.

Pharmacodynamics

The pharmacodynamics of attenuated vaccines involve the interaction of the attenuated pathogen with the host's immune system. Upon administration, the vaccine induces both humoral (antibody-mediated) and cell-mediated immunity. This leads to the development of memory cells that ensure a faster and more effective response upon subsequent exposure to the actual pathogen.

Pharmacokinetics

Attenuated vaccines are generally administered via subcutaneous or intramuscular injection. The pharmacokinetics are characterized by the distribution of the vaccine components within the body, with the attenuated organisms replicating locally and inducing an immune response. The onset of immunity typically occurs within weeks, and the duration of immunity can vary depending on the specific vaccine.

Contra-indications

• Severe immunodeficiency
• Pregnant women (specific live attenuated vaccines)
• Severe allergic reactions to vaccine components

Adverse effects

• Injection site reactions (pain, swelling, redness)
• Low-grade fever
• Malaise
• Rash
• Rare neurological complications (e.g., Guillain-Barré syndrome)

Interactions

• Immunosuppressive agents (may reduce vaccine efficacy)
• Blood products (may interfere with immune response to vaccine)
• Other live vaccines (timing may affect immune response)

Precautions

• History of allergic reactions to previous vaccinations
• Presence of active infections
• Chronic illnesses that may affect immune response

Pregnancy

Live attenuated vaccines are generally contraindicated during pregnancy due to potential risks to the fetus.

Breast-feeding

Most live attenuated vaccines are considered safe during breastfeeding, but caution and consultation with a healthcare provider are advised.

Storage

Store in a refrigerator at 2-8°C. Do not freeze. Protect from light.

Formulations

• Injectable suspension
• Oral suspension
• Lyophilized powder for reconstitution

Indications

• Ebola virus disease
• Supportive treatment for Ebola virus infection

Dosage

Children: Refer to specific treatment guidelines for Ebola virus disease in children.

Adults: Refer to specific treatment guidelines for Ebola virus disease.

Mechanism of action

Ebola virus primarily infects macrophages and dendritic cells, leading to impaired immune response and significant inflammatory responses. The virus enters host cells via receptor-mediated endocytosis, where it releases its genetic material into the cytoplasm. The viral proteins interfere with host cell signaling pathways, inhibiting the production of type I interferons, which are crucial for antiviral defense. This evasion of immune response contributes to the virus's virulence.

Pharmacodynamics

Ebola virus infection leads to a rapid and severe inflammatory response, often resulting in multi-organ failure. The dysregulation of the immune response can cause a cytokine storm, leading to increased vascular permeability, shock, and coagulopathy. The disease progression can be exacerbated by the systemic inflammatory response, which can result in significant tissue damage and organ dysfunction.

Pharmacokinetics

Pharmacokinetic data specific to Ebola virus treatments can vary widely depending on the specific therapeutic agent used. However, treatments may involve monoclonal antibodies, antiviral agents, or supportive care. The metabolism and excretion of these agents depend on their specific mechanisms and pathways. For example, monoclonal antibodies may have prolonged half-lives due to their nature of being proteins, while antiviral agents may be metabolized by the liver and excreted via the kidneys.

Adverse effects

• Fever
• Fatigue
• Diarrhea
• Vomiting
• Abdominal pain
• Muscle pain
• Headache
• Hemorrhagic manifestations
• Rash
• Conjunctivitis

Precautions

• Use caution in patients with a history of severe allergic reactions.
• Implement strict infection control measures due to the highly contagious nature of the virus.
• Monitor for signs of bleeding or organ failure.

Pregnancy

Ebola virus infection in pregnancy poses significant risks, including miscarriage and maternal mortality. It is crucial to evaluate the risks and benefits before any treatment.

Breast-feeding

Breastfeeding is not recommended during Ebola virus infection due to the risk of transmission through breast milk.

Storage

Ebola virus is a highly infectious pathogen and should be handled in a biosafety level 4 facility. Specimens need to be stored and transported under strict containment protocols.

Indications

• Measles
• Mumps
• Rubella
• Varicella (chickenpox)
• Yellow fever
• Rotavirus
• Intranasal influenza

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and vaccine type.

Adults: Refer to specific product guidelines for dosing information, as it can vary by vaccine type and brand.

Mechanism of action

Live vaccines work by introducing a weakened or attenuated form of a pathogen into the body. This stimulates the immune system to recognize and respond to the pathogen, leading to the production of antibodies and memory cells that provide long-term protection against future infections by the same pathogen.

Pharmacodynamics

The pharmacodynamics of live vaccines involve the activation of both humoral and cellular immunity. Following vaccination, the immune system generates a robust response, including the production of specific antibodies and the activation of T cells that can recognize and eliminate infected cells. This dual action helps establish long-term immunity.

Pharmacokinetics

The pharmacokinetics of live vaccines vary depending on the specific vaccine. Generally, the vaccine is administered via injection, allowing the live attenuated organisms to enter the bloodstream. The immune response typically begins within days and can last for years, depending on the vaccine. Live vaccines are usually stored under refrigeration to maintain their viability, and they should be administered within their expiration dates.

Interactions

• livevaccines + abrocitinib: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + baricitinib: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + filgotinib: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + dexrazoxane: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + iron chelators: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + ozanimod: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + ponesimod: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + siponimod: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + upadacitinib: Severe (increases risk of generalised infection (possibly life-threatening))
• livevaccines + diroximelfumarate: Moderate (increases risk of generalised infection (possibly life-threatening))

Indications

• Ebola virus disease caused by Zaire ebolavirus
• Post-exposure prophylaxis in high-risk individuals
• Treatment of confirmed Ebola cases

Dosage

Children: Refer to specific antiviral treatment guidelines for pediatric dosing information, as doses can vary based on the medication used.

Adults: Refer to specific antiviral treatment guidelines for dosing information, as doses can vary based on the medication used.

Mechanism of action

The Zaire ebolavirus primarily infects host cells by binding to specific receptors on the cell surface, leading to viral entry via macropinocytosis. Once inside, the virus hijacks the host cell's machinery to replicate its RNA and produce viral proteins. The newly formed virions are then released from the host cell, allowing for further infection of adjacent cells. This cycle of infection leads to widespread cell death and immune system dysregulation.

Pharmacodynamics

The pharmacodynamics of antiviral treatments for Zaire ebolavirus involve the inhibition of viral replication and the modulation of the host immune response. Some therapeutic agents target viral proteins or RNA synthesis, while others aim to enhance immune responses to control and eliminate the infection. The effectiveness of such treatments can vary depending on the timing of administration and the severity of the disease.

Pharmacokinetics

The pharmacokinetics of antiviral treatments for Ebola, including those targeting the Zaire strain, often involve rapid absorption, distribution, metabolism, and excretion, although specific parameters can vary widely depending on the drug. Generally, these agents are administered intravenously or orally and are distributed widely in body tissues. Metabolism may occur in the liver, and excretion is typically via urine. The half-life and clearance rates can differ based on the specific antiviral used.

Pregnancy

Safety during pregnancy has not been established. Use only if clearly needed and the benefits outweigh the risks.

Breast-feeding

It is unknown whether this drug is excreted in human milk. Caution is advised.

Storage

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