Smallpox: Risks of VaccinationPatricia Lee MD

Smallpox Vaccine Does Not Contain Smallpox

• Live virus – Vaccinia - pox type virus– Vaccinia - mutated cowpox or variola virus

• Unsure when switch came from cowpox to vaccinia

– Can be transmitted to other parts of the body or other people

• Other live virus vaccines: measles, mumps, rubella, chickenpox

–Calf-lymph vaccine Dryvax–contains polymyxin B, neomycin sulfate, streptomycin sulfate, chlorotetracycline hydrochloride

–Vero monkey kidney cell vaccine, human fibroblast cell vaccine- expected 2004

Smallpox Vaccine

• 15 million doses available to US, plan to purchase 300 million more doses– Dilution seems effective with less side effects

• Vaccinate up to 3 days post-exposure

• Up to 4-7 days post-exposure may offer some protection or modify severity of disease

Vaccination and Immunity

• First time vaccination: (45% population)– immunity lasts 3-5 yrs

• Revaccination: – longer immunity- 10 yrs

• A successful vaccination: “take”

• If unsuccessful, revaccinate 7-10 days later

Vaccinia

• Another pox type virus related to smallpox

• Vaccine does not contain smallpox virus– cannot spread smallpox

• Vaccinia can be spread through the vaccination site – touching site or bandage– Meticulous vaccination site care

• It is not airborne

Vaccination• Given in upper arm• Bifurcated needle dipped in vaccine solution.

– Skin is pricked 15 times in a few seconds. Small amount of bleeding

• 3-4 days: red itchy bump • Week 1: large blister fills with pus, drains• Week 2 : blister begins to dry up and form scab• Week 3: Scab falls off, scar remains• First timers: stronger take• Diluted vaccine is effective

Who should NOT receive smallpox vaccine?

• Up to 25% of population will be ineligible• Any person who has one of the following

conditions OR lives with someone who does – Skin conditions:

• Eczema or atopic dermatitis – even if not active

• Other skin conditions – burns, chickenpox, shingles, impetigo, herpes, severe acne, psoriasis

– Immunocompromised, eg. CA, steroid use, HIV

– Pregnancy or plans to become pregnant within one month of vaccination

Who should NOT receive smallpox vaccine?

• In addition, you should not get the vaccine if:– Less than 18 yrs old– Have small children < 1 yr old– Moderate or short term illness– Breastfeeding– Allergic to vaccine or any of its ingredients

• Polymyxin B sulfate, Streptomycin sulfate, Neomycin sulfate• Chlorotetracycline hydrochloride

– Inflammatory eye disease

• EXCEPTION: If exposed to smallpox – you EXCEPTION: If exposed to smallpox – you should get vaccine regardless of health statusshould get vaccine regardless of health status

Reactions to Smallpox Vaccination

• Normal, typically mild reactions– Do not require treatment– Arm sore with intense erythema surrounding site– Tender impressive axillary adenopathy – Low grade fever 101, myalgias, malaise– 1 of 3 people may miss work, school, recreational

activity, or have insomnia around day 4-7

• Bacterial infections of site - children

Reactions to Smallpox Vaccination

• Serious Reactions– 1000 people/million vaccinated – Autoinoculation: common

• Vaccinia rash limited to one area

• Wash hands with soap and water after touching site

– Generalized vaccinia - widespread vaccinia rash –due to viremia

– Erythyma multiforme, other non vesicular rash– Vaccinia keratitis

Reactions to Smallpox Vaccination

• Life Threatening Reactions**– 14-52 people/million vaccinated for 1st time

(300,000)– Eczema vaccinatum – due to autoinoculation or

contact with vaccinee – Progressive vaccinia (vaccinia necrosum) – seen in

immunocompromised– Postvaccinal encephalitis

**based on studies in 1968

Reactions to Smallpox Vaccination

• 1-3 people/million vaccinated may die (30)

• Serious reactions are lower for revaccination – 0.1 deaths/million

• USA adverse events rate unknown: – higher due to number of immunocompromised

(CA, Tx, HIV, eczema, etc.) or lower due to improved health care???

Satellite lesions

Satellite lesions

Revaccination

Revaccination

Vaccinia keratitis

Progressive vaccinia

Erythyma multiforme

Erythyma multiforme and revaccination

Post vaccination commentsDecember 5, 2002 Washington Post

• 200 healthy university students inoculated– 1/3 missed at least 1 day of work or school

• “The reactions we saw were quite remarkable”• “I just wanted to go to bed for a day or two”• “I thought, can you just chop off my arm?”• “You can’t scratch it, it’s all bandaged up; all I could do was smack it”• “I was pretty miserable for 1 week”• “Range of reactions from small rash to swelling the size of a grapefruit”• “You are going to have to be prepared to see these individuals and to see

really bad takes…you’ll wonder if they are bacterial infections; in some cases the rash will move up the arm and onto the chest. The vaccinee requires a lot of TLC”

Vaccine Safety

• Best protection available against smallpox

• Most people experience mild reaction

• Treatment against serious reactions– Vaccinia Immune Globulin (VIG) 700 doses

• CDC controlled

• Enough if 6 million vaccinated

– Cidofovir 3500 doses • enough if 15 million vaccinated

What are we waiting for?• Section 304 Homeland Security Bill covering

liability of vaccinations, 1/24/03• Tommy Thompson, Sec HHS will declare

immunization program to start• Illinois to finalized issues of workman’s

compensation• Chicago

– 21 hospitals have replied with smallpox response plans– 7 hospitals have declined to participate– Others await corporate decisions regarding employee

post vaccination care

Smallpox Response Team

• CDC rollout vaccination plan for smallpox response team in hospitals– 50 health care workers/hospital

• Expected 30 day completion

• Revaccinate 7-10 days after

Top 15 Things I Learned About Smallpox Vaccination

• Vaccination is preventative

• Vaccinia virus is used for vaccine

• Previously vaccinated are not immune

• Can vaccinate up to 3 days post exposure

• Vaccination site must be covered with occlusive dressing and inspected before work duty

Top 15 Things I Learned About Smallpox Vaccination

• Ineligible for vaccination: either have or live with someone who has:– Pregnancy– Extensive skin disease– Immunodeficiency– Inflammatory eye disease– Eczema (past present or “healed”)– Vaccine component allergy– Child < 1 year old

Top 15 Things I Learned About Smallpox Vaccination

• 1 of 3 persons mild reactions: may miss school or work 5-7 days post-vaccination

• 1000 persons/million serious reactions

• 14-52 persons/million with life-threatening reactions

• 1-3 persons/million will die

• VIG and/or Cidofovir for serious reactions

Top 15 Things I Learned About Smallpox Vaccination

• Previously vaccinated have a lower risk of vaccine complications

• Vaccine cannot spread smallpox

• Patients who have been vaccinated will come to the ED and require a lot of TLC

• If smallpox exposed: all contraindications are null – Everyone should be vaccinated