Smallpox Vaccine

1. See also
   1. Smallpox
2. Indications
   1. Postexposure prophylaxis
   2. High risk of exposure as Biological Weapon
3. Contraindications (Relative if actual Smallpox exposure)
   1. Also applies to conditions in household or sex contacts
   2. Consider concurrent VariolaImmunoglobulin 0.3 ml/kg
   3. Eczematous Dermatitis
   4. Exfoliative condition (e.g. Burn Injury, Shingles)
   5. Immunodeficiency
      1. Chemotherapy or Radiation Therapy
      2. Immunosuppresant use within 3 months of vaccine
      3. Corticosteroids (including ocular Corticosteroids)
         1. Prednisone >2 mg/kg/day for over 2 weeks or
         2. Prednisone 20 mg/day for over 2 weeks
      4. Human Immunodeficiency Virus (HIV)
      5. Hereditary Immunodeficiency
      6. Pregnancy
      7. Concurrent moderate to severe illness
   6. Heart disease or 3 or more Cardiac Risk Factors
   7. Age under 12 months
   8. Unless emergency, avoid use if age under 18 or over 65
   9. Breastfeeding
   10. Allergy to vaccine components
       1. Polymyxin B, Streptomycin, Tetracycline or Neomycin
       2. Phenol
       3. Latex Allergy (Latex in vaccine vial stopper)
4. Technique
   1. Obtain sterile bifurcated needle
   2. Dip needle into reconstituted vaccine ampule
   3. Limit vaccine to 5 mm area
   4. Scratch skin with 15 perpendicular needle strokes
      1. Trace of blood should appear with 15-30 seconds
   5. Wipe excess vaccine from skin
   6. Apply bandage securely to inoculation site
5. Site care post vaccination
   1. Keep site always covered to prevent virus transmission
      1. Change dressing every 1-3 days
      2. Dispose of dressings as infectious waste
      3. Do not apply any topical agents (e.g. cream) to site
   2. Site care to prevent autoinoculation or transmission
      1. Infectious from day 3 to 28 (when scab falls off)
      2. Avoid touching or exposing others to site
      3. Wash skin carefully if accidental exposure occurs
   3. Other measures to prevent transmission
      1. Isolate linen and clothing from others in house
      2. Avoid public swimming until scab falls off (4 weeks)
      3. Wear long sleeve clothing over bandaged site
   4. Should not disrupt work in most occupations
      1. Food preparation may continue
      2. Travel is not contraindicated
      3. Healthcare workers may still care for patients
6. Adverse effects
   1. Uniform skin response (Jennerian response, "Take")
      1. Red Papule at vaccine site by 3 days
      2. Vesicle by day 5
      3. Jennerian Pustule by day 7
         1. White, umbilicated Pustule on erythematous base
      4. Dark crust forms and falls off by 3 weeks
      5. Full progression timing depends on prior exposure
         1. Primary vaccination: 15 days
         2. Revaccination: 8 days
   2. Inadequate Vaccination (Requires re-vaccination)
      1. Peak erythema within 48 hours (hypersensitivity)
   3. Common Constitutional symptoms
      1. Fever between days 4-14 (70% of children)
      2. Regional Lymphadenopathy
7. Complications
   1. Post-vaccine Encephalitis (15 per 1 million vaccinees)
      1. Occurs within 2 weeks of vaccine
      2. Mortality: 25%
      3. Morbidity: Serious neurologic sequelae in 25%
      4. No treatment other than supportive care
   2. Progressive Vaccinia (Vaccinia gangrenosa)
      1. Only occurs in immunodeficient patients
      2. Suspect if lesions progress beyond 2 weeks
      3. Non-healing skin lesions progressing to skin necrosis
      4. Frequently fatal
      5. May respond to medications
         1. VariolaImmunoglobulin 0.6 ml/kg divided over 24 h
         2. Cidofovir (Vistide)
         3. Ribavirin
   3. Eczema Vaccinatum (10-39 per 1 million vaccinees)
      1. Occurs if patient has Atopic Dermatitis
      2. Variola skin lesions involve eczematous skin
      3. VariolaImmunoglobulin 0.6 ml/kg divided over 24 hour
         1. Reduces potential mortality from 40% to 1%
   4. Autoinoculation (600 per 1 million vaccinees)
      1. Accidental inoculation of face, eyes, mouth, genitals
   5. Other complications
      1. Generalized Vaccinia
         1. Onset 6-9 days after vaccination
         2. Benign with resolution within 2 weeks
      2. Ocular Vaccinia
         1. Opthalmology referral
         2. Avoid VIG (Corneal Opacity risk)
         3. Consider ocular antiviral (e.g. Trifluridine)
      3. Myopericarditis
         1. Presents within 30 days of vaccination
         2. Recently reported as more common adverse effect
8. Storage of vaccine
   1. Vaccine may be refrigerated 60 days post-reconstitution
9. Efficacy
   1. Single dose results in protection by 10 days in 95%
   2. Immunity lasts 5 years or more after vaccination
      1. Booster dose extends duration of immunity
10. Drug Interactions
    1. Most vaccinations are safe to concurrently administer
    2. Do not administer with Varicella Vaccine
       1. Due to differentiating potential reactions
    3. Do not use with immunosuppressants or Corticosteroids
       1. See contraindications above
11. Reporting
    1. See Immunization Resources
12. References
    1. (1990) MMWR Morb Mortal Wkly Rep 40(RR-14):445-8
    2. Breman (2002) N Engl J Med 346:1300-8
    3. Cono (2003) MMWR Recomm Rep 52(RR-4):1-28
    4. Goldstein (1975) Pediatrics 55:342-7
    5. Grabenstein (2003) JAMA 289:3278-82
    6. Henderson (1999) JAMA 281:2127-37
    7. Kempke (1960) Pediatrics 26:176-89
    8. Maurer (2003) Am Fam Physician 68(5):889-96