A live attenuated vaccination called Varivax (Varicella Virus Vaccine) promotes active protection against the varicella virus. It is used in the prevention of varicella (Chickenpox) in the following group of patients:

• For the prevention of varicella in persons aged 1 year and older
• All kids, teens, and adults who don't exhibit immunity are advised to get vaccinated, according to the Advisory Committee on Immunization Practices (ACIP).
• Vaccination is especially required for:
  • Adolescents and adults in households with children
  • Household contacts of immunocompromised patients
  • Persons in environments where transmission has been previously reported
  • People who reside or work in places where transmission is quite likely, such as childcare providers, instructors, residents, and institutional employees
  • Nonpregnant women of childbearing age
  • International travelers
  • Health care people
• It is laso used as off-label medicine in postexposure prophylaxis of varicella

Varivax Dose in Adults

Varivax dosage in the treatment of Varicella immunization:

• • Two doses are given of 0.5 mL separated by ≥ 1 month (1-2 months apart).

• All children and adults without proof of immunity are advised to receive two doses of the vaccine, according to the ACIP.
• People who received only one dose of a varicella vaccine should receive a second dose.

• Canadian labeling:
  • 2 separate dosages 0.5 mL are administered 4 to 8 weeks apart (Varivax III) or after 6 weeks.

• Adults and adolescents who have only had one dose of the vaccine are advised to get a second dose, according to the NACI.

Off Label Dosage in the Postexposure prophylaxis of healthy, previously unvaccinated individuals:

• It is best to provide 0.5 mL subQ within 3 days of exposure, albeit this can happen up to 5 days later.

Varivax Dose in Childrens

Varivax dose in the treatment of Primary immunization:

• CDC and ACIP recommendations:
  • Children ≥12 months:
    • It is given as 0.5 mL subQ per dose for a total of 2 doses administered as:
      • 12 - 15 months of age and 4 - 6 years of age.
    • If more than three months have gone since the first treatment, the second dose may be given sooner.
    • It is regarded as valid if the second dose is administered four weeks following the first dose.
• Canadian labeling:
  • • Children:
      • Varilrix:
        • 2 doses of 0.5 mL S/C separated by ≥6 weeks
      • Varivax III:
        • 0.5 mL S/C as a single dose
    • Adolescents:
      • SubQ:
        • 2 doses  0.5 mL S/C given separated by 4 to 8 weeks (Varivax III) or ≥6 weeks (Varilrix)

Varivax dose in the treatment of Catch-up immunization:

• Children and Adolescents:
  • ACIP recommendations: Series should not be restarted.
  • • 0.5 mL subQ per dose is given for a total of 2 doses administered as follows:
      • first dose administered on the chosen day
      • If the patient is younger than 13 years old, the second dose is typically administered at least 3 months or at least 1 month following the first dose (if age is more than 13 years).

Varivax dose in the postexposure prophylaxis of healthy, previously unvaccinated individuals:

• Children older than 12 months and Adolescents:
  • Ideally, 0.5 mL subQ should be administered within 72 hours of exposure, however it is possible to use it up to 120 hours later.

Pregnancy Risk Factor: D

• Pregnancy should be avoided for three months after receiving the varicella virus vaccination, which is contraindicated for females.
• These women's miscarriage and birth defect rates did not appear to be higher than background levels.
• Additionally, there were no newborns born with anomalies suggestive with congenital varicella syndrome.
• Congenital varicella syndrome can result from varicella infection in the first or second trimester.
• The newborn can contract varicella if the mother contracts it starting five days before delivery and lasting until two days after delivery.
• During a prenatal checkup, all women should be examined for immunity; those who don't show any signs of immunity should be immunised following the completion or termination of pregnancy.

Varivax vaccine use during breastfeeding:

• Status of varicella is nor known in breast milk.
• The decision to breastfeed after an immunization should take into account the chance of infant exposure, the effects of breastfeeding to the infant, and benefits of treatment to the mother.
• Guidelines recommend that immunization should not be delayed due to breastfeeding and vaccinated women may continue breastfeeding.
• Breastfed infants should be vaccinated as recommended schedules.

Varivax Dose in Renal Disease:

• There are no dosage adjustments given in the manufacturer's labeling in patients with renal disease.

Varivax Dose in Liver Disease:

• There are no dosage adjustments given in the manufacturer's labeling.in patients with liver disease.

Common Side Effects of Varivax vaccine include:

• Local:
  • Injection site reaction includes
    • Swelling
    • Pain
    • Hematoma
    • Numbness
    • Stiffness
    • Induration
    • Erythema
• Miscellaneous:
  • Fever

Less Common Side Effects of Varivax Vaccine Include:

• Central Nervous System:
  • Irritability
  • Fatigue
  • Nervousness
  • Headache
  • Malaise
  • Sleep Disturbance
  • Chills
• Dermatologic:
  • Diaper Rash
  • Skin Rash
  • Contact Dermatitis
  • Urticaria
  • Dermatitis
  • Eczema
  • Pruritus
  • Miliaria
  • Xeroderma
  • Varicella-Like Rash
• Gastrointestinal:
  • Constipation
  • Anorexia'
  • Nausea
  • Aphthous Stomatitis
  • Dental Discomfort
  • Vomiting
  • Abdominal Pain
  • Diarrhea
• Genitourinary:
  • Hematologic & Oncologic: Lymphadenopathy
  • Herpes Labialis
• Hypersensitivity:
  • Hypersensitivity Reaction
• Neuromuscular & Skeletal:
  • Neck Stiffness
  • Myalgia
  • Arthralgia
• Ophthalmic:
  • Eye Discomfort
• Otic:
  • Otitis
• Respiratory:
  • Respiratory Tract Disease (Lower/Upper)
  • Cough

Contraindication to Varivax Vaccine Include:

• Patients with AIDs or other clinical signs of HIV
• Having primary and acquired immunodeficiency states;
• active & untreated tuberculosis
• severe allergic reaction involving the vaccine, gelatin, neomycin, or any other formulation component
• Individuals with compromised immune systems, immunosuppressed patients, including those with lymphomas, leukaemia, or other malignant
• neoplasms that affect the lymphatic or bone marrow systems (including immunosuppressive doses of corticosteroids)
• Suffering from febrile illness
• Pregnant

Warnings & Precautions

• Anaphylactoid/ Allergic reactions:
  • Epinephrine 1 mg/mL for anaphylactoid and hypersensitivity responses should be available when using the vaccination.
• CNS infection:
  • Immunocompetent people who had previously received the varicella virus vaccine have experienced cases of meningitis and encephalitis caused by the vaccine strain of the virus months to years after vaccination.
  • Cases frequently include an existing or recent herpes zoster rash.
• Syncope:
  • Utilization of injectable vaccines has been associated with syncope, which can result in severe secondary injuries such skull fracture and brain bleeding.
  • If syncope occurs, actions should be taken to restore cerebral perfusion and prevent injury from falls.
• Acute illness:
  • Although the manufacturer states that fever is a contraindication, current recommendations allow vaccination delivery to people with mild acute illnesses.
• Altered immunocompetence:
  • Immunodeficient or immunosuppressed individuals should not use this vaccination.
  • Near family and friends of immunocompromised people can get the majority of age-appropriate immunizations.
  • When possible, live vaccinations should be administered up to 4 weeks before immunosuppression and prevented within 2 weeks of immunosuppression.
  • After receiving immunosuppressive therapy, live vaccinations shouldn't be administered for at least 3 months.
• HIV:
  • HIV-infected children who have CD4+ T lymphocyte percentages above 15% for their age can receive live attenuated varicella vaccine.
  • Children above the age of 8, teenagers, and adults with CD4+ T-lymphocyte counts under 200 cells per microliter are eligible for vaccination.

Monitor:

• Keep an eye out for allergy symptoms like rash and fever.
  15 minutes after injection, keep an eye out for syncope and allergic responses.
• Maintain the patient in a supine or Trendelenburg position if seizure-like activity accompanied by syncope occurs in order to restore appropriate cerebral perfusion.

How to administer Varivax vaccine?

SubQ:

• Inject in the lateral or anterior portion of the upper thigh.
• Give intramuscularly or intravenously not.
• Give right away after reconstitution.
• Only administer Varilrix (a Canadian medication) to the deltoid area.
• It shouldn't be combined with other injections or immunizations.
• For each injection, separate needles and syringes should be used.
• By administering the shot while seated or lying down, syncope-related risks can be avoided.
   

Mechanism of action of Varivax (Varicella virus) vaccine:

• It is a live attenuated vaccine.
• By triggering cell-mediated and humoral immune reactions, it provides active immunisation against the varicella-zoster virus, which is the cause of Chickenpox.

The onset of action:

• After a single treatment and two doses, the rates of séroconversion after 4–6 weeks are 97% and 99.9%, respectively.
• The seroconversion rate was around 75% after 4 weeks of the first dosage and 99% after 4 weeks of the second dose in adults and adolescents older than 13 years old.

Duration of action:

• Antibody titers can be found 10 years after vaccination.
• The antibody titers may vary by year and age group, but for children at ten years and for adults and adolescents at six years post-immunization, they range from 99% to 100%.
• The wild type of varicella may increase antibody levels.

International Brands of VAR:

• Okavax
• V-Z Vax
• Vaccin Varilrix
• Varcelvax
• Varicela Biken
• Varilrix
• Varipox
• Varivax

Varicella Virus Vaccine in Pakistan:

• Okavax - Sanofi Aventis
• Varilrix - GSK
• Varivac - Changchun Changsheng Life Sciences/Hi-Warble
• Vaxapox - Sind Medical stores