PRIORIX TETRA VACCINE

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 mumps through vaccination
• Management of mumps infection
• Monitoring for complications such as orchitis or meningitis

Dosage

Children: Refer to the BNF for Children for specific vaccination schedules and dosage recommendations related to the MMR vaccine.

Adults: Refer to the specific guidelines for vaccination, typically the MMR vaccine is administered as a two-dose series, with the first dose given at 1 year of age and a second dose at 4 to 6 years of age. Further details should be checked in the relevant vaccination schedule.

Mechanism of action

The mumps virus enters host cells by binding to sialic acid receptors on the surface of the cells. Once inside, the virus releases its RNA genome, leading to the production of viral proteins and replication of the viral genome. The newly formed viral particles are then released from the host cell, allowing for further infection of adjacent cells.

Pharmacodynamics

Mumps primarily affects the salivary glands but can also impact other organs such as the testes, ovaries, pancreas, and central nervous system. The immune response to the infection typically involves the activation of T cells and the production of antibodies, which help to clear the virus from the body. The severity of the disease can vary, with some individuals experiencing mild symptoms while others may develop complications such as orchitis or meningitis.

Pharmacokinetics

The pharmacokinetics of the mumps virus is not applicable in the traditional sense as it is a viral infection. However, the incubation period for mumps is typically 16 to 18 days, with the virus being contagious from approximately three days before to five days after the onset of parotitis. The immune response develops over a period of weeks, leading to long-lasting immunity in most cases post-infection or vaccination.

Adverse effects

• Fever
• Headache
• Muscle pain
• Swelling of the salivary glands
• Orchitis (inflammation of the testes)
• Oophoritis (inflammation of the ovaries)
• Meningitis
• Encephalitis

Precautions

• Individuals with weakened immune systems should be monitored closely.
• Vaccination may be less effective in those with specific conditions affecting the immune response.

Pregnancy

Mumps vaccination is generally avoided during pregnancy unless the benefits outweigh the risks, as the effects of the vaccine on fetal development are not fully established.

Breast-feeding

Vaccination is not contraindicated during breastfeeding, but consultation with a healthcare provider is recommended.

Storage

Store at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.

Formulations

• Live attenuated mumps virus vaccine

Indications

• Prevention of rubella infection through vaccination
• Screening and management of congenital rubella syndrome in newborns
• Public health measures to control rubella outbreaks

Dosage

Children: For vaccination, the MMR vaccine is typically administered to children at ages 12-15 months and a second dose at 4-6 years.

Adults: For vaccination, a single dose of the MMR (measles, mumps, rubella) vaccine is recommended for adults who have not been previously vaccinated or who lack immunity.

Mechanism of action

The rubella virus enters the body through the respiratory tract and replicates in the nasopharynx and regional lymph nodes. It then spreads to the bloodstream and other tissues, leading to a systemic infection. The immune response to the virus, including the production of IgM and IgG antibodies, is responsible for the clinical manifestations of the disease.

Pharmacodynamics

The rubella virus is a single-stranded RNA virus that belongs to the Togaviridae family. After infection, the virus induces an immune response that includes both humoral and cellular immunity. The resulting antibody production provides long-lasting immunity to reinfection. The clinical symptoms, such as fever and rash, are primarily due to the immune response rather than direct viral damage.

Pharmacokinetics

The incubation period for rubella is typically 14 to 21 days. The virus is present in the nasopharynx and urine. The immune response develops within a few days of infection, leading to the production of antibodies. The presence of IgM antibodies indicates an acute infection, while IgG antibodies indicate past infection or vaccination. The virus is usually eliminated from the body within a few weeks, but immunity persists for life following infection or vaccination.

Contra-indications

• Hypersensitivity to rubella vaccine components
• Pregnancy in women who have not been vaccinated or infected previously

Adverse effects

• Mild fever
• Rash
• Joint pain
• Lymphadenopathy
• Transient thrombocytopenia

Interactions

• Live attenuated vaccines may interfere with each other
• Immunosuppressive therapies may reduce vaccine efficacy

Precautions

• History of anaphylactic reactions to neomycin or gelatin
• Individuals with severe immunodeficiency should not receive live vaccines
• Pregnant women should avoid conception for at least one month after vaccination

Pregnancy

Rubella vaccination is contraindicated during pregnancy due to potential harm to the fetus. Women are advised to receive the vaccine before conception.

Breast-feeding

Rubella vaccination is considered safe during breastfeeding.

Storage

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

Formulations

• Live attenuated rubella 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

Indications

• Prevention of varicella (chickenpox) in children and adults
• Post-exposure prophylaxis in individuals at high risk of severe disease

Dosage

Children: Refer to specific guidelines for varicella vaccination and management in children.

Adults: Refer to specific guidelines for varicella vaccination and management in adults.

Mechanism of action

The varicella-zoster virus enters the body through the respiratory tract and mucosal tissues. It replicates in lymphoid tissues and then disseminates through the bloodstream, leading to a systemic infection. The virus causes the characteristic skin lesions by infecting epidermal cells, leading to cell lysis and the formation of vesicular lesions. The immune response to the infection ultimately leads to the resolution of the disease and the formation of latent virus in sensory nerve ganglia.

Pharmacodynamics

The pharmacodynamics of varicella involves the immune response elicited by the body upon infection. The primary response includes the production of antibodies specific to VZV, which help to neutralize the virus and prevent further infection. Additionally, T-cell mediated immunity plays a crucial role in controlling the infection and preventing reactivation of the virus later in life, which can result in herpes zoster (shingles).

Pharmacokinetics

Varicella-zoster virus has a complex pharmacokinetic profile. After initial infection, the virus undergoes replication in lymphoid tissue, followed by viremia and subsequent infection of the skin. The onset of the rash typically occurs 10 to 21 days after exposure. The virus can remain dormant in sensory ganglia and may reactivate later in life, causing herpes zoster. The vaccine, when administered, stimulates an immune response without causing the disease, leading to the establishment of immunity.

Contra-indications

• Hypersensitivity to varicella vaccine components
• Immunocompromised individuals
• Pregnant women

Adverse effects

• Injection site reactions (pain, redness, swelling)
• Mild rash
• Fever
• Fatigue
• Headache

Interactions

• Corticosteroids may reduce vaccine effectiveness
• Immunosuppressive therapies may alter immune response to vaccination

Precautions

• Assess for history of allergic reactions to previous vaccines
• Monitor for potential interactions with immunosuppressive medications
• Consider the risk of transmission to susceptible individuals

Pregnancy

Varicella vaccine is contraindicated during pregnancy due to potential risks to the fetus.

Breast-feeding

Breastfeeding is not a contraindication for varicella vaccination; however, consult healthcare provider for individual cases.

Storage

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

Formulations

• Live attenuated varicella vaccine, administered subcutaneously