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Smallpox Vaccine: Overview for Health Care Response Teams Thomas G. Franck, MD, MPH Regional Physician Consultant Office of Emergency Preparedness & Response.

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Presentation on theme: "Smallpox Vaccine: Overview for Health Care Response Teams Thomas G. Franck, MD, MPH Regional Physician Consultant Office of Emergency Preparedness & Response."— Presentation transcript:

1 Smallpox Vaccine: Overview for Health Care Response Teams Thomas G. Franck, MD, MPH Regional Physician Consultant Office of Emergency Preparedness & Response Virginia Department of Health January 2003

2 Objectives To briefly review smallpox disease To briefly review smallpox disease To gain an in depth understanding of smallpox vaccine, including: To gain an in depth understanding of smallpox vaccine, including: –history of smallpox vaccination –overview of vaccinia –indications –contraindications –normal response –complications

3 Taxonomy Family: Poxviridae Family: Poxviridae Genus: Orthopoxviruses Genus: Orthopoxviruses Smallpox (variola) Smallpox (variola) Cowpox Cowpox Monkeypox Monkeypox Vaccinia Vaccinia 93% DNA Homology

4 Smallpox Caused by Variola virus Caused by Variola virus Unique to humans Unique to humans Person-to-person spread Person-to-person spread –usually via close contact - droplets –contaminated materials (uncommon) –aerosolized droplet nuclei spread (rare) 30% case-fatality rate on average 30% case-fatality rate on average

5 Smallpox: Clinical Features Incubation: days (range 7-17) Incubation: days (range 7-17) Prodrome: lasts 2-4 days Prodrome: lasts 2-4 days –fever, malaise, headache, backache, vomiting Eruptive stage (Rash): Eruptive stage (Rash): –Oral cavity/pharynx face, hands, forearms lower extremities trunk –Synchronous progression: maculopapules vesicles pustules scabs –Lesions on palms /soles –Infectious stage (especially 1 st week)

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8 Smallpox - Treatment Treatment Treatment –Supportive care –No treatment proven effective –Experimental treatment with antivirals, e.g., Cidofovir Prevention/Prophylaxis Prevention/Prophylaxis –Vaccination - protective if given within 3 days of exposure

9 Smallpox: Why the Concern Now? Last case in US in 1949 Last case in US in 1949 Last naturally acquired case in 1977 Last naturally acquired case in 1977 Disease declared eliminated by WHO in 1980 Disease declared eliminated by WHO in 1980 Stocks of Variola virus held by U.S. & Russia Stocks of Variola virus held by U.S. & Russia Bio Weapons programs in several countries Bio Weapons programs in several countries Recent Intelligence review: 4 countries may have covert stocks of smallpox virus – Russia, Iraq, North Korea, and France Recent Intelligence review: 4 countries may have covert stocks of smallpox virus – Russia, Iraq, North Korea, and France

10 1796:Edward Jenner develops vaccine (cowpox) 1805:Use of cows to produce vaccine 1940s: Freeze-drying of Vaccinia 1965:Licensure of bifurcated needle 1972:Routine vaccination stopped in U.S. 1983:Vaccine removed from civilian market 1990:U.S. Military vaccination stops Smallpox Vaccine: History

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16 Smallpox Vaccine Live virus called Vaccinia Live virus called Vaccinia An orthopoxvirus, genetically distinct from other orthopoxviruses such as cowpox, monkeypox, and variola (cause of smallpox) An orthopoxvirus, genetically distinct from other orthopoxviruses such as cowpox, monkeypox, and variola (cause of smallpox) Origin unknown: May be a virus now extinct in nature Origin unknown: May be a virus now extinct in nature

17 Vaccinia Vaccine Dryvax (Wyeth Laboratories) Dryvax (Wyeth Laboratories) Contains NY City Board of Health strain Contains NY City Board of Health strain 2.7 million doses licensed (phase 1)* 2.7 million doses licensed (phase 1)* Enough vaccine to vaccinate every single person in the country in an emergency* Enough vaccine to vaccinate every single person in the country in an emergency* *December 2002

18 Vaccine Efficacy: Pre-Exposure Reduces chance of getting infected (i.e., decreases secondary attack rate) Reduces chance of getting infected (i.e., decreases secondary attack rate) 91%-97% reduction in cases among case contacts with vaccination scar 91%-97% reduction in cases among case contacts with vaccination scar For those infected, reduces fatality rate and severity of disease For those infected, reduces fatality rate and severity of disease

19 Mack, J. Inf Dis, 1972

20 Vaccine Efficacy: Post Exposure Generally prevents smallpox, or significantly decreases severity, if given within 3 days of exposure Generally prevents smallpox, or significantly decreases severity, if given within 3 days of exposure Vaccination 4 to 7 days post-exposure still offered protection to many people, but significantly less than vaccination before 4 days Vaccination 4 to 7 days post-exposure still offered protection to many people, but significantly less than vaccination before 4 days

21 Vaccine Efficacy: Post Exposure Postexp vacc Never vacc Vacc <10 days Never vacc Vacc <7 days Never vacc Smallpox AR % (Madras) (Pakistan)

22 Duration of Immunity High level of protection (95-100%) for 3-5 years following vaccination High level of protection (95-100%) for 3-5 years following vaccination Immunity wanes after 5 years, but some residual protection evident at 10 and even 20+ years Immunity wanes after 5 years, but some residual protection evident at 10 and even 20+ years Reduction in disease severity with any history of vaccination Reduction in disease severity with any history of vaccination However, best protection if vaccinated <3-5 yrs ago; we cannot rely on previous vaccinations to protect our population and we should consider the population to lack immunity to smallpox. However, best protection if vaccinated <3-5 yrs ago; we cannot rely on previous vaccinations to protect our population and we should consider the population to lack immunity to smallpox.

23 Smallpox Vaccine Indications: Non-Emergency Current Indications: Current Indications: –Laboratory workers who handle cultures or animals infected with non-highly attenuated vaccinia or other Orthopoxviruses New Recommendations: New Recommendations: –Public health, hospital, and other personnel, generally years of age, who may have to respond to a smallpox case or outbreak

24 Smallpox Vaccine Indications: Emergency Situations Ring Vaccination Ring Vaccination –Persons exposed to initial release –Close contact with confirmed or suspected case –Direct care or transportation of confirmed or suspected case –Laboratory personnel –Persons with risk of contact with infectious materials from case Mass Vaccination of entire populations? Mass Vaccination of entire populations?

25 Contraindications: Non-Emergency Situations Eczema/atopic dermatitis (active or history of) or household contact with eczema/atopic dermatitis Eczema/atopic dermatitis (active or history of) or household contact with eczema/atopic dermatitis Other active skin conditions (allergic rash, burns, impetigo, chickenpox, shingles, herpes,psoriasis, severe acne, etc.) or household contact with acitve skin condition Other active skin conditions (allergic rash, burns, impetigo, chickenpox, shingles, herpes,psoriasis, severe acne, etc.) or household contact with acitve skin condition Immunosuppression or household contact with immunosuppression Immunosuppression or household contact with immunosuppression Pregnancy or pregnant household contact Pregnancy or pregnant household contact Breastfeeding Breastfeeding Infants (not advised in children < 18) Infants (not advised in children < 18) Severe allergic reaction to prior vaccination or vaccine component Severe allergic reaction to prior vaccination or vaccine component

26 Contraindications: Immunodeficiency Conditions causing immunodeficiency: Conditions causing immunodeficiency: –HIV, leukemia, lymphoma, other cancers, agammaglobulinemia, certain autoimmune disorders (e.g., SLE), other immune disorders Treatments causing immunodeficiency: Treatments causing immunodeficiency: –Chemotherapy, radiation treatment, antimetabolites, alkyltating agents, organ transplant meds, high-dose corticosteroids –Immunomodulatory medications? Unknown

27 Contraindications: Eczema/Atopic Dermatitis Eczema: a red, itchy rash that lasts at least two weeks and then comes and goes Eczema: a red, itchy rash that lasts at least two weeks and then comes and goes It is estimated that at least 15 million people in U.S. have atopic dermatitis It is estimated that at least 15 million people in U.S. have atopic dermatitis These people are at risk of a serious complication, eczema vaccinatum These people are at risk of a serious complication, eczema vaccinatum

28 Contraindications: Emergency Situations Exposed persons – no contraindications Exposed persons – no contraindications Unexposed persons – generally same as non-emergency situations w/ some modifications, depending on situation Unexposed persons – generally same as non-emergency situations w/ some modifications, depending on situation

29 Vaccine Administration Surgical needle Surgical needle Vaccinostyle Vaccinostyle Rotary lancet Rotary lancet Jet injector Jet injector Bifurcated needle* Bifurcated needle* *Only administration technique currently in use.

30 Vaccination Technique

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33 Vaccination Site Care Remember – live vaccinia virus is present at site of vaccination until scab falls off on its own, usually 2-3 weeks. Remember – live vaccinia virus is present at site of vaccination until scab falls off on its own, usually 2-3 weeks. Dressing Dressing Health care setting: 3 layers of protection – gauze, semipermeable dressing, shirt Health care setting: 3 layers of protection – gauze, semipermeable dressing, shirt Non-health care setting: 2 layers of protection – gauze & shirt Non-health care setting: 2 layers of protection – gauze & shirt Avoid salves and ointments Avoid salves and ointments Avoid touching/scratching site and picking scab Avoid touching/scratching site and picking scab

34 Post-Vaccination Follow-up Semipermeable dressing: change dressing at least every 3-5 days and as needed Semipermeable dressing: change dressing at least every 3-5 days and as needed Gauze dressing secured by tape: change dressing every 1-3 days and as needed Gauze dressing secured by tape: change dressing every 1-3 days and as needed Take evaluation: 7 days after vaccination (+/- 1 day) Take evaluation: 7 days after vaccination (+/- 1 day) If significant side effects or adverse event, follow-up with designated health care provider If significant side effects or adverse event, follow-up with designated health care provider

35 Clinical Response to Vaccination* Sign/symptom Papule Vesicle Pustule Maximum erythema Scab Scab separation Time after Vacc 3 days 5-6 days 7-11 days 8-12 days 14 days 21 days *typical response in a nonimmune person

36 Clinical Response to Vaccination Major (primary) reaction Major (primary) reaction –Indicates viral replication has occurred and vaccination was successful No reaction or equivocal reaction No reaction or equivocal reaction –No immunity and vaccination must be repeated

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38 Major Reaction* (6-8 days after vaccination) Primary vaccination Primary vaccination –Vesicular or pustular lesion –Area of definite palpable induration surrounding a central crust or ulcer Revaccination Revaccination –Less pronounced and more rapid progression –Pustular lesion or induration surrounding a central crust or ulcer *WHO Expert Committee on Smallpox, 1964

39 Day 3 PrimaryRevaccination

40 Day 7 PrimaryRevaccination

41 Day 10 PrimaryRevaccination

42 Day 14 Primary Revaccination

43 Normal Variants: Satellite Lesions

44 Normal Variants: Cellulitis & Lymphangitis

45 Smallpox Vaccination: Normal Side Effects Fever: 10% of adults Fever: 10% of adults Localized soreness: 35-47% Localized soreness: 35-47% Headache/muscle aches: 40-50% Headache/muscle aches: 40-50% Redness/swelling > 3 inches: 15% Redness/swelling > 3 inches: 15% 1/3 may feel bad enough to miss work, school, activity, or have trouble sleeping 1/3 may feel bad enough to miss work, school, activity, or have trouble sleeping

46 Smallpox Vaccination: Adverse Events Contact transmission: spread vaccinia to others Contact transmission: spread vaccinia to others Inadvertent autoinoculation: spread to other sites on body Inadvertent autoinoculation: spread to other sites on body Generalized vaccinia: spread throughout body Generalized vaccinia: spread throughout body Eczema vaccinatum: severe skin reaction Eczema vaccinatum: severe skin reaction Progressive vaccinia (vaccinia necrosum) Progressive vaccinia (vaccinia necrosum) Postvaccinial encephalitis Postvaccinial encephalitis Death Death

47 Accidental Inoculation Accidental auto-inoculation of cheek with vaccinia virus, approximately 5 days old. Primary take on arm, days old. Photo courtesy of John M. Leedom, MD.

48 Accidental Inoculation

49 Generalized Vaccinia Generalized vaccinia in an apparently normal child. Recovered without sequelae. Photo courtesy of John M. Leedom, M.D.

50 Generalized Vaccinia

51 Eczema Vaccinatum

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53 Progressive Vaccinia

54 Post-Vaccinial Encephalitis Autoimmune process Autoimmune process No predictors of susceptibility No predictors of susceptibility Supportive care; no specific therapy Supportive care; no specific therapy Vaccinia Immune Globulin is not effective and is not recommended. Vaccinia Immune Globulin is not effective and is not recommended % mortality; and 25% had permanent neurological sequelae

55 Vaccinia Keratitis

56 Vaccine Adverse Events Complication # per million Household transmission 27 Accidental autoinoculation Generalized vaccinia Eczema vaccinatum Progressive vaccinia Encephalitis3-12 Death1-2

57 Complication Rates of Vaccination Rates (per million vaccinations) U.S., 1968 (ten state survey) Total 212 Postvaccinal Encephalitis 31.5 Progressive Vaccinia 339 Eczema Vaccinatum 9242 Generalized Vaccinia Inadvertent Autoinoculation RevaccinationPrimaryVaccinationComplication Total 212 Postvaccinal Encephalitis 31.5 Progressive Vaccinia 339 Eczema Vaccinatum 9242 Generalized Vaccinia Inadvertent Autoinoculation RevaccinationPrimaryVaccinationComplication

58 VIG: Vaccinia Immune Globulin Indicated: Indicated: –Eczema vaccinatum –Progressive vaccinia –Generalized vaccinia (if severe or recurrent) –Accidental implantation (ocular or extensive lesions) Not Recommended: Not Recommended: –Accidental implantation (mild instances) –Generalized vaccinia (mild or limited - most instances) –Erythema multiforme –Encephalitis Contraindicated: Contraindicated: –Vaccinia keratitis

59 Issues for Discussion HIV testing HIV testing Pregnancy testing Pregnancy testing Vaccination site care – who, how often? Vaccination site care – who, how often? Should healthcare provider continue to work? Should healthcare provider continue to work? Liability & workers compensation Liability & workers compensation

60 …it now becomes too manifest to admit of controversy, that the annihilation of the Small Pox, the most dreadful scourge of the human species, must be the final result of this practice. -Edward Jenner, 1801


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