varicella virus vaccine (Varivax)

Indications

• all healthy children between 12 months & 18 years
  • children 12 months to 13 years who have not been immunized & have not had chickenpox should receive 1 vaccination
  • children between 13 & 18 years of age require 2 vaccinations 4-8 weeks apart
• added to childhood immunization schedule for infants 12-28 months of age (12-15 months)
• recommended to be given with measles, mumps, rubella vaccine (MMR)
• a second vaccination at age 4-6 years, to be given with MMR as MMRV (ProQuad) now recommended
• susceptible adolescents & adults in one of the following groups
  • health care workers
  • household contacts of immunosuppressed patients
  • workers in schools or day-care centers
  • young adults in closed or semi-closed populations
    • college students
    • military
  • non-pregnant women of child-bearing age
  • international travelers who anticipate close contact with local populations

Contraindications

• hypersensitivity to any component of the vaccine including gelatin
• history of anaphylactoid reaction to neomycin
• individuals with blood dyscrasias, leukemia, lymphoma, or other malignant neoplasm affecting the bone marrow or lymphatic systems
• individuals on immunosuppressive therapy
• primary & acquired immunodeficiency states
• family history of congenital or hereditary immunnodeficiency
• active, untreated tuberculosis
• febrile illness
• pregnancy

Caution:

• avoid pregnancy until 3 months after vaccination
• avoid if breast feeding
• immediate treatment for anaphylactoid reaction should be available
• defer vaccination for 5 months following blood transfusions or immune globulin therapy
• avoid immune globulin therapy for 2 months following vaccination
• avoid salicylates for 5 weeks after vaccination (Reye syndrome)
• vaccinated individuals should not have close contact with susceptible high-risk individuals following vaccination (newborns, pregnant women, immunocompromised individuals)

pregnancy-category -

safety in lactation ?

Dosage

• children 12 months to 12 years: 0.5 mL SC
  • 2 dose vaccination schedule since 2006
• children >12 years & adults:
  • 2 doses of 0.5 mL SC separated by 4-8 weeks

Lyophilized powder for injection:

• 0.5 mL single dose vials
• store in freezer
• can be stored refrigerated for 72 hours

Pharmacokinetics

• elimination: liver
• onset of action: 4-6 weeks after vaccination

Adverse effects

• most common (1-10%)
  • pain, fever, irritability, nervousness, fatigue, disturbed sleep, headache, malaise, chills, redness, rash, pruritus, generalized varicella-like rash, diarrhea, loss of appetite, nausea/vomiting, abdominal pain, hematoma, induration & stiffness at the site of injection, myalgia, arthralgia, otitis, upper respiratory illness, allergic reaction
• uncommon (< 1%)
  • febrile seizures (causality not established), pneumonitis
• complications in immunodeficient children (contraindication)

Drug interactions

• immunosuppressive agents
  • decrease effectiveness of vaccine
  • increase risk of varicella disease from vaccine
• salicylates may increase the risk of Reye syndrome

Notes

Effectiveness:

• 48% of vaccinated children vs 86% of unvaccinated children developed chickenpox upon exposure in a daycare center
• 73% effective if given at 12 months of age 99% effective if given at 15 months of age difference only applies to 1st year after vaccination
• unknown if vaccine will prevent shingles
• universal childhood varicella vaccination diminishes mortality
• vaccinated individuals can still develop chicken pox, but their clinical course is usually milder than in unvaccinated patients

More general terms

• live virus vaccine

More specific terms

• Herpes zoster (shingles) vaccine (Zostavax, Shingrix)

Additional terms

• Varicella [Herpes] zoster virus (VZV); human herpesvirus 3 (HHV3)

Component of

• measles virus vaccine live attenuated/mumps virus vaccine/rubella virus vaccine live/varicella virus vaccine