MAREKS CF VACCINE

Indications

• Herpes simplex virus infections
• Genital herpes
• Cold sores (oral herpes)
• Herpes zoster (shingles)
• Varicella (chickenpox)

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines for paediatric patients.

Adults: Refer to the BNF for specific dosing recommendations based on the type of herpes infection and individual patient factors.

Mechanism of action

Antiviral agents such as aciclovir, famciclovir, and valaciclovir inhibit viral DNA synthesis. They are nucleoside analogues that interfere with the viral enzyme DNA polymerase, preventing the replication of viral DNA. This action reduces the viral load and alleviates the severity of herpes outbreaks.

Pharmacodynamics

Antiviral medications exhibit a selective toxicity towards viral cells as they are preferentially activated by viral enzymes. This leads to a decrease in the viral load, alleviating symptoms and promoting healing of lesions. The clinical efficacy of these drugs is maximized when initiated early during an outbreak.

Pharmacokinetics

After oral administration, aciclovir is absorbed with a bioavailability of 15-30%. It is widely distributed in body fluids and tissues, with a volume of distribution of approximately 0.6 L/kg. The drug is metabolized in the liver and primarily excreted unchanged in urine. The elimination half-life is approximately 2.5 to 3 hours in patients with normal renal function. Dosage adjustments may be required in cases of renal impairment.

Interactions

• aciclovir+herpes-zostervaccine: Unknown (decreases efficacy)
• covid-19vaccine+herpes-zostervaccine: Unknown (affects response)
• famciclovir+herpes-zostervaccine: Unknown (decreases efficacy)
• normalimmunoglobulin+herpes-zostervaccine: Unknown (decreases efficacy)
• aciclovir+herpes-zostervaccine,live: Unknown (decreases efficacy)
• covid-19vaccine+herpes-zostervaccine,live: Unknown (affects response)
• famciclovir+herpes-zostervaccine,live: Unknown (decreases efficacy)
• valaciclovir+herpes-zostervaccine,live: Unknown (decreases efficacy)
• valaciclovir+herpes-zostervaccine: Unknown (decreases efficacy)

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

• Prevention of Marek's disease in poultry
• Vaccination in young chickens to protect against MDV

Dosage

Children: Refer to the specific manufacturer's guidelines for vaccination protocols in young poultry. Doses may vary based on the vaccine type used.

Adults: Refer to the specific manufacturer's guidelines for vaccination protocols in adult poultry. Doses may vary based on the vaccine type used.

Mechanism of action

Marek's disease virus primarily functions by integrating its DNA into the host cell's genome, leading to transformation of the infected cells. This results in the proliferation of T-cells and the formation of lymphomas, causing clinical disease. The vaccines work by providing an immune response that prevents the virus from establishing infection.

Pharmacodynamics

The pharmacodynamics of Marek's disease vaccines involve the stimulation of the immune system to recognize and combat the Marek's disease virus. The immune response generated includes both humoral and cellular immunity, which helps prevent the disease's onset and reduces the severity of clinical signs in vaccinated birds.

Pharmacokinetics

The pharmacokinetics of Marek's disease vaccines are not directly applicable as they are biological products rather than conventional drugs. However, once administered, the vaccine components are taken up by the immune system, leading to the development of immunity over a period of time. The onset of immunity typically occurs within a few weeks after vaccination.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Skin rash
• Allergic reactions

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of hypersensitivity
• Consider potential interactions with other medications

Pregnancy

The safety of Marek's vaccine in pregnant women has not been established. Caution is advised.

Breast-feeding

It is unknown if Marek's vaccine is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

Store at 2 to 8 degrees Celsius. Protect from light and do not freeze.

Formulations

• Live attenuated vaccine

Indications

• High-quality protein source
• Nutritional support for muscle maintenance
• Source of B vitamins
• Source of selenium
• Source of zinc

Dosage

Children: Protein needs for children vary by age. It is recommended to consult specific dietary guidelines for children, which suggest that the intake of protein should be proportionate to their age, weight, and level of physical activity.

Adults: The recommended dietary allowance for protein varies, but generally, adults require approximately 46-56 grams of protein per day, which can be met through the consumption of turkey as part of a balanced diet.

Mechanism of action

Turkey meat contains proteins that are broken down into amino acids during digestion, which the body utilizes for various physiological functions, including muscle repair, hormone production, and immune function. The presence of tryptophan, an amino acid found in turkey, is known to affect serotonin levels in the brain, which may influence mood and sleep patterns.

Pharmacodynamics

Turkey is rich in amino acids, vitamins, and minerals, which can support overall health. The bioavailability of nutrients such as zinc and B vitamins from turkey contributes to various metabolic processes and functions, including energy production, immune response, and nervous system health. The consumption of turkey is associated with satiety and may impact dietary patterns due to its protein content.

Pharmacokinetics

Nutrient absorption from turkey occurs primarily in the gastrointestinal tract, where proteins are digested into amino acids, and vitamins and minerals are absorbed into the bloodstream. The rate of absorption may vary based on the method of cooking and individual digestive health. Protein metabolism involves hepatic processing, where amino acids are utilized or stored as needed by the body.

Pregnancy

Generally considered safe to consume during pregnancy, but should be cooked thoroughly to avoid foodborne illnesses.

Breast-feeding

Typically safe for breastfeeding mothers, but should be prepared properly to ensure safety for both mother and infant.

Storage

Store in a cool, dry place. Fresh turkey should be refrigerated and consumed within a few days or frozen for longer storage.

Indications

• Influenza
• HIV/AIDS
• Hepatitis B and C
• Herpes simplex virus infections
• Cytomegalovirus infections
• COVID-19
• Respiratory syncytial virus infections

Dosage

Children: Refer to specific antiviral agents for dosing guidance.

Adults: Refer to specific antiviral agents for dosing guidance.

Mechanism of action

Viruses infect host cells by attaching to specific receptors on the cell surface. Once inside, they hijack the host cell's machinery to replicate their genetic material and produce viral proteins. New viral particles are assembled and released from the host cell, often destroying the cell in the process. The specific mechanism can vary depending on the virus type, including integration into the host genome in retroviruses or utilizing specific pathways for replication.

Pharmacodynamics

The pharmacodynamics of antiviral agents depend on the specific virus and the mechanism of action. Antiviral drugs may inhibit viral entry into host cells, block viral replication, or prevent the assembly of new virions. The effectiveness of antiviral therapy often relates to the stage of viral replication and the immune response of the host.

Pharmacokinetics

Pharmacokinetics of antiviral drugs varies widely based on the specific medication used. Generally, antiviral agents are absorbed through the gastrointestinal tract and distributed throughout the body. They may undergo hepatic metabolism and are often excreted through the kidneys. The half-life of these drugs can range from a few hours to several days, influencing dosing schedules.