MEASLES VACCINE LIVE ATTENUATED (FREEZE-DRIED)

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

• 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 measles through vaccination
• Management of measles infection in symptomatic patients
• Prevention of complications associated with measles infection

Dosage

Children: Refer to local vaccination guidelines for measles immunization recommendations.

Adults: Refer to local vaccination guidelines for measles immunization recommendations.

Mechanism of action

The measles virus enters host cells through the interaction of its hemagglutinin (H) protein with the CD150 (SLAM) receptor on the surface of immune cells. Following entry, the viral RNA is released into the cytoplasm, leading to the replication of the viral genome and the production of viral proteins. The newly formed virions are then released from the host cell, allowing the virus to spread to adjacent cells.

Pharmacodynamics

Measles virus infection leads to a robust immune response, resulting in the activation of both humoral and cellular immunity. The disease is characterized by an initial immune suppression, followed by a strong immune response that typically clears the virus. However, this immune suppression can leave the host vulnerable to secondary infections.

Pharmacokinetics

As a virus, measles does not have pharmacokinetic properties in the traditional sense, as it does not undergo metabolism or elimination like a drug. Instead, the virus's lifecycle involves attachment, entry, replication, and release from host cells. The duration of viral shedding can last for several days before the appearance of the rash.

Contra-indications

• Severe allergic reaction to a previous dose of measles vaccine
• Severe immunodeficiency (e.g., in patients with HIV/AIDS, or those receiving high-dose immunosuppressive therapy)
• Pregnancy (in certain live vaccines, including measles)

Adverse effects

• Fever
• Rash
• Diarrhea
• Otitis media
• Pneumonia
• Encephalitis (rare)

Interactions

• Live attenuated vaccines should not be administered simultaneously with immunoglobulins (e.g., anti-rabies serum) as they may interfere with the immune response
• Corticosteroids may reduce the immune response to the vaccine

Precautions

• Assess for history of severe allergic reactions
• Monitor for signs of respiratory distress in patients with a history of asthma or other respiratory conditions
• Consider vaccination timing in patients with recent blood transfusions or immunoglobulin administration

Pregnancy

Measles vaccination is contraindicated during pregnancy due to potential harm to the fetus. Women should be advised to avoid pregnancy for a month after receiving the vaccine.

Breast-feeding

Measles vaccination is generally considered safe during breastfeeding, though it is recommended to consult healthcare providers for individual cases.

Storage

Store in a refrigerator at 2°C to 8°C, do not freeze. Protect from light.

Formulations

• Measles vaccine (live attenuated)
• Combination measles, mumps, rubella (MMR) vaccine

Indications

• Prevention of infectious diseases such as measles, mumps, rubella, hepatitis B, influenza, and human papillomavirus (HPV)
• Travel vaccinations for diseases endemic to certain regions
• Vaccination for at-risk populations, such as those with compromised immune systems or specific occupational exposures

Dosage

Children: Dosage varies by vaccine type and age; refer to the BNF for Children for specific dosing information.

Adults: Dosage varies by vaccine type and indication; refer to specific guidelines for each vaccine.

Mechanism of action

Vaccines work by mimicking an infection. They introduce a harmless component of a pathogen (antigen) to the immune system, prompting the body to produce an immune response. This includes the generation of antibodies and memory cells that provide long-term immunity. Upon subsequent exposure to the actual pathogen, the immune system is primed to respond more rapidly and effectively.

Pharmacodynamics

The pharmacodynamics of vaccines involves the activation of both humoral and cellular immunity. Vaccines stimulate B cells to produce antibodies against the pathogen, while T cells are activated to destroy infected cells. This dual response helps to establish immunological memory, which enables a faster and more robust response upon re-exposure to the pathogen.

Pharmacokinetics

Vaccines are administered via various routes, including intramuscular, subcutaneous, and oral. After administration, the antigens are presented to antigen-presenting cells, which activate T cells and stimulate B cell proliferation and differentiation. The half-life of vaccine-induced immunity varies depending on the type of vaccine, with some providing lifelong immunity and others requiring booster doses to maintain protection.

Contra-indications

• Severe allergic reaction (anaphylaxis) to a component of the vaccine
• Severe immunocompromised state for live attenuated vaccines

Adverse effects

• Local reactions at the injection site (pain, redness, swelling)
• Fever
• Fatigue
• Headache
• Muscle pain
• Joint pain
• Nausea

Interactions

• Immunosuppressive medications may reduce vaccine efficacy
• Concurrent administration of some vaccines may require spacing to optimize immune response

Precautions

• History of allergic reactions to vaccines or vaccine components
• Pregnancy (specific vaccines may be contraindicated)
• Moderate to severe acute illness with or without fever

Pregnancy

Consult healthcare provider. Some vaccines are contraindicated during pregnancy, while others are recommended.

Breast-feeding

Generally considered safe, but consult healthcare provider regarding specific vaccines.

Storage

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

Formulations

• Liquid suspension for injection
• Lyophilized powder for reconstitution