APPENDIX 2 Vaccinia Virus • Accidental infection following transfer from the vac- cination site to another site (autoinoculation) or to Disease Agent: another person following intimate contact Likelihood of Secondary Transmission: • Vaccinia virus • Significant following direct contact Disease Agent Characteristics: At-Risk Populations: • Family: Poxviridae; Subfamily: Chordopoxvirinae; • Individuals receiving smallpox (vaccinia) vaccination Genus: Orthopoxvirus • Individuals who come in direct contact with vacci- • Virion morphology and size: Enveloped, biconcave nated persons core with two lateral bodies, brick-shaped to pleo- • Those at risk for more severe complications of infec- morphic virions, ~360 ¥ 270 ¥ 250 nm in size tion include the following: • Nucleic acid: Nonsegmented, linear, covalently ᭺ Immune-compromised persons including preg- closed, double-stranded DNA, 18.9-20.0 kb in length nant women • Physicochemical properties: Virus is inactivated at ᭺ Patients with atopy, especially those with eczema 60°C for 8 minutes, but antigen can withstand 100°C; ᭺ Patients with extensive exfoliative skin disease lyophilized virus maintains potency for 18 months at 4-6°C; virus may be stable when dried onto inanimate Vector and Reservoir Involved: surfaces; susceptible to 1% sodium hypochlorite, • No natural host 2% glutaraldehyde, and formaldehyde; disinfection of hands and environmental contamination with soap Blood Phase: and water are effective • Vaccinia DNA was detected by PCR in the blood in 6.5% of 77 military members from 1 to 3 weeks after Disease Name: smallpox (vaccinia) vaccination that resulted in a major skin reaction. • Progressive vaccinia (vaccinia necrosum or vaccinia • In the absence of complications after immunization, gangrenosum) recently published PCR and culture data suggest that • Generalized vaccinia viremia with current vaccines must be rare 3 weeks • Eczema vaccinatum after vaccination. • Postvaccination encephalomyelitis Survival/Persistence in Blood Products: Priority Level: • Unknown • Scientific/Epidemiologic evidence regarding blood Transmission by Blood Transfusion: safety: Theoretical • Never observed despite the coexistence of extensive • Public perception and/or regulatory concern regard- immunization activity and blood donation and trans- ing blood safety: Very low; the existence of any threat fusion during much of the 20th century. However, this of vaccinia to blood safety is dependent on the occur- was not systematically investigated. rence of an accidental or intentional release of variola, or a threat of bioterrorism sufficient to require Cases/Frequency in Population: a significant, widespread, reintroduction of smallpox • There is minimal use of the vaccine at this time. (vaccinia) immunization. • The source of current concern is speculation about • Public concern regarding disease agent: Absent cases occurring upon implementing widespread vac- Background: cination programs in anticipation of or response to the reintroduction of smallpox into the population. • Origin is unknown Incubation Period: • Currently used in smallpox vaccination regimen in individuals who may be exposed to variola (smallpox) • Complications of immunization tend to occur 7-21 proceeding from vesicle to pustule with a maximal days after inoculation. response at 8-11 days. • In one study, vaccinia DNA was infrequently detect- able up to 21 days after uncomplicated immuniza- Common Human Exposure Routes: tion. However, in another study, viral cultures were negative. Published data on the duration of vaccinia • Intentional dermal inoculation for vaccination viremia are not available. 160S TRANSFUSION Volume 49, August 2009 Supplement APPENDIX 2 Likelihood of Clinical Disease: • Animal models and very limited human data suggest the antiviral agent cidofovir may have clinical activity. • Low, except in immunocompromised persons Primary Disease Symptoms: Agent-Specific Screening Question(s): • Generalized vaccinia: Disseminated maculopapular • Currently required by the FDA and included in or vesicular rash that occurs because of lympho- AABB’s Donor History Questionnaire (despite only hematogenous spread 4-19 days following vaccina- minimal smallpox (vaccinia) immunization activity at tion. Immunocompetent hosts usually experience a this time): benign clinical course, whereas this can be life threat- ᭺ In the past 8 weeks, have you had any vaccina- ening in immunocompromised persons. tions or other shots? • Progressive vaccinia: Necrotic, locally progressive ᭺ In the past 8 weeks, have you had contact with virus replication in the skin and soft tissue of a vacci- someone who had a smallpox vaccination? nation site (generally seen in vaccinees or their con- tacts with defective cellular or humoral immunity) Laboratory Test(s) Available: • Eczema vaccinatum: Localized or generalized papular, vesicular, pustular, or erosive rash syndrome • No FDA-licensed blood donor screening test exists. approximately 5-19 days after exposure through vac- • Antibody assays might be useful as evidence of cination or close contact with a smallpox vaccinee, immunity. with substantial mortality. Lesions have a predilec- • Research assays exist for virus isolation, virus detec- tion for areas currently or previously affected by tion by direct fluorescent assay in lesion samples, and atopic dermatitis. nucleic acid amplification. None of these are licensed • Erythema multiforme: Usually benign rash illness in the US nor are they immediately suitable for high- after immunization throughput applications. • Accidental skin infection or keratitis through transfer- ence or intimate skin contact Currently Recommended Donor Deferral Period: • Postvaccination encephalomyelitis • Fetal infection • 21 days or until vaccination scab separated (longer of • Cardiomyopathy, myocarditis, pericarditis the two) for well vaccinees • Secondary (bacterial) infection of vaccination site • 14 days after resolution of all symptoms in vaccinees might have an analog if transfusion transmission with complications or in vaccinee contacts with occurred and resulted in typical vaccinia skin lesions complications • Prospective donors who are symptomatic after Severity of Clinical Disease: contact with recipients of smallpox vaccine are • Certain postvaccination manifestations carry sub- deferred until complete healing and spontaneous stantial morbidity and mortality (progressive separation of scabs from localized skin lesions, as vaccinia, eczema vaccinatum, heart disease, postvac- visually verified by donor room staff. If the scab was cination encephalomyelitis, fetal vaccinia, keratitis, otherwise removed, deferral is for 3 months from the erythema multiforme) in the appropriate host. vaccination of the source vaccinee. If the date of vac- cination of the source is unknown but could have Mortality: been within the last 3 months, deferral is for 2 months from the donor’s attempt to donate. • Mortality rates vary by complication. Range is down- ward from 25% for postvaccination encephalomyeli- Impact on Blood Availability: tis. Historical rates of mortality and severe morbidity may be modified with the availability of modern sup- • Agent-specific screening question(s): Minimal in the portive care, vaccinia immune globulin, and anti- absence of widespread, emergent, population-based virals (e.g., cidofovir). immunization initiatives. Impact will be small in Chronic Carriage: conjunction with local or narrowly targeted immu- nization programs. Impact will be major with • Not recognized community-wide immunization programs and could Treatment Available/Efficacious: be devastating to the blood supply during rapidly implemented, widespread regional or national • Uncontrolled data suggest that vaccinia immune immunization programs. globulin may mitigate complications of vaccination. • Laboratory test(s) available: Not applicable Volume 49, August 2009 Supplement TRANSFUSION 161S APPENDIX 2 Impact on Blood Safety: 7. Food and Drug Administration. Guidance For Industry: recommendations for deferral of donors • Agent-specific screening question(s): Minimal, given and quarantine and retrieval of blood and blood lack of evidence of viremia from vaccination in recent products in recent recipients of smallpox vaccine studies (vaccinia virus) and certain contacts of smallpox • Laboratory test(s) available: Not applicable vaccine recipients. US Department of Health and Leukoreduction Efficacy: Human Services, FDA, Center for Biologics Evalua- tion and Research. 2002. [cited 2009 June]. Available • Unknown from: http://www.fda.gov/BiologicsBloodVaccines/ • Cellular tropism studies using primary hemato- GuidanceComplianceRegulatoryInformation/ lymphoid cells suggest some viral clearance by leuko- Guidances/Blood/ucm075115.htm reduction can be anticipated. 8. Henderson DA, Moss B. Smallpox and Vaccinia. In: Plotkin SA, Orenstein WA, editors. Vaccines, 3rd ed. Pathogen Reduction Efficacy for Plasma Derivatives: Philadelphia: WB Saunders; 1999. [cited 2009 May]. • This enveloped virus was inactivated below the limit Available from: http://www.ncbi.nlm.nih.gov/books/ of detection in one study (that used 6 logs of virus) bv.fcgi?rid=vacc.chapter.3 with pasteurization, caprylate, and solvent-detergent 9. Hopkins RJ, Lane JM. Clinical efficacy of intramuscu- treatments. lar vaccinia immune globulin: a literature review. Clin • Sterile filtration of plasma for further manufacture Infect Dis 2004;39:819-26. reduced titers approximately 4 logs in one study. 10. Kempe CH. Studies on smallpox and complications