ROTATEQ

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

• Influenza prevention
• Viral respiratory infections
• Pediatric vaccination programs

Dosage

Children: Refer to specific guidelines based on the type of reassortant vaccine used, as dosing can vary.

Adults: Refer to specific guidelines based on the type of reassortant vaccine used, as dosing can vary.

Mechanism of action

Reassortant viruses work by introducing specific genes from a virulent strain into a backbone of a less virulent or attenuated strain. When administered, the vaccine stimulates the immune system to recognize and respond to the surface antigens of the virus, particularly hemagglutinin and neuraminidase, leading to the production of neutralizing antibodies. This prepares the immune system to respond more effectively to natural infections by the wild-type virus.

Pharmacodynamics

The pharmacodynamics of reassortant vaccines involve the interaction between the vaccine and the immune system, leading to the activation of both humoral and cellular immunity. Following vaccination, the body produces specific antibodies against the reassorted viral antigens, enhancing the immunological memory. This results in a quicker and more robust immune response upon subsequent exposure to the actual virus, reducing the severity and duration of the disease.

Pharmacokinetics

Reassortant vaccines are typically administered via intramuscular or subcutaneous injection. After administration, the vaccine components are processed by antigen-presenting cells, leading to T-cell activation and subsequent antibody production. The onset of immunity usually occurs within a few weeks, with the duration of protective immunity varying based on the specific vaccine and population factors. Clearance of the vaccine components is primarily through normal metabolic pathways, with no specific half-life defined due to the nature of vaccines.

Pregnancy

The safety of reassortant vaccines during pregnancy is not fully established. Pregnant individuals should consult healthcare providers before vaccination.

Breast-feeding

Reassortant vaccines are generally considered safe during breastfeeding, but it is advisable to consult a healthcare professional.

Storage

Reassortant vaccines should be stored in a refrigerator at 2-8 degrees Celsius, protected from light. Do not freeze.

Indications

• Rotavirus gastroenteritis
• Prevention of rotavirus-related diarrhea in infants and children

Dosage

Children: Refer to the BNF for Children for specific vaccination schedules and dosing information related to rotavirus vaccination.

Mechanism of action

Rotavirus infects and replicates in the epithelial cells of the small intestine. The virus disrupts the normal function of these cells, leading to malabsorption of nutrients and water. The infection triggers an inflammatory response, resulting in increased intestinal permeability, secretion of electrolytes and water into the intestinal lumen, and subsequent diarrhea.

Pharmacodynamics

The body's immune response plays a crucial role in controlling rotavirus infections. The production of antibodies against rotavirus is stimulated by natural infection and vaccination. These antibodies help neutralize the virus and prevent future infections. The severity of the disease is often related to the host's immune status and the age of the child at the time of infection.

Pharmacokinetics

As a virus, rotavirus does not follow traditional pharmacokinetic profiles like absorption, distribution, metabolism, and excretion seen with drugs. Instead, the focus is on the replication cycle of the virus within the host's intestinal cells and the resultant immune response. The stability of rotavirus outside the host is significant for transmission, as it can survive on surfaces for long periods.

Contra-indications

• Severe allergic reaction to any component of the vaccine
• History of intussusception
• Severe combined immunodeficiency (SCID)
• Moderate or severe acute illness

Adverse effects

• Diarrhea
• Vomiting
• Fever
• Irritability
• Intussusception (rarely)
• Allergic reactions (rare)

Interactions

• Immunosuppressive therapies may reduce vaccine efficacy
• Other live vaccines should generally be given at the same visit or separated by at least 4 weeks

Precautions

• Monitor for signs of intussusception after vaccination
• Use with caution in individuals with a history of gastrointestinal disorders
• Pregnant women should not receive the vaccine

Pregnancy

The vaccine is not recommended during pregnancy due to lack of safety data.

Breast-feeding

Safe to use during breastfeeding; no contraindications.

Storage

Store in a refrigerator (2°C to 8°C). Do not freeze.

Formulations

• Oral suspension for vaccination

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.