VACCINES FOR TRAVELERS

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VACCINES FOR TRAVELERS
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Vaccines for the traveler

• Reduce the risk of vaccine preventable diseases
  for the individual traveler
• Reduce the risk of international transmission of
  diseases, and reintroduction of diseases into
  countries
• Moderate risk Hepatitis A 20cases/1000
  travelers per month
• Low risk Polio 20/1 000 000 unimmunized
  travelers, Japanese encephalitis lt1/1 000 000
  travelers

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Factors affecting disease risk and choice of
vaccines in travelers

• Destination, duration of travel, nature and
  conditions of travel, occurrence of outbreaks
• Category of traveler leisure and pleasure,
  business, luxury or adventure, refugee, combat
• Vaccines officially required for entry, vaccines
  dependent on disease risk
• Person factors immunization/disease history,
  age, allergies, co-morbid disease
• Costs, time available pretravel

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Travel vaccines

• Yellow fever
• Hepatitis A B
• Typhoid
• Cholera
• Meningococcal disease
• Diphtheria
• Polio
• Rabies
• Japanese encephalitis
• European tick borne encephalitis
• Influenza
• Measles
• Tetanus
• BCG

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Yellow fever vaccine

• Attenuated 17 D strain prepared in chick embryos
• International Health Regulations compulsory
  vaccine for travel to endemic countries or
  persons returning from an endemic area to a
  potentially receptive non-endemic area
• Administered in licensed yellow fever centres
• Administer 10 days before travel, durationgt10
  years
• Little risk of yellow fever to travelers

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• Yellow fever maps
• Yellow fever in tourists

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Yellow fever vaccine

• C/I egg allergy, immunosuppression including
  symptomatic HIV, pregnancy, children lt 6 months
• ADR YF vaccine-associated neurologic disease, YF
  vaccine-associated viscerotropic disease
• Yellow fever in travelers-
• Chan Lancet 2001, Martin Lancet 2001

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Hepatitis A vaccine

• Commonest vaccine preventable travel infection
• gt95 protection 4 weeks after first dose
• Vaccine versus immunoglobulin?
• Testing for immunity pre vaccination?

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Polio vaccine

• Low risk in travelers
• Single dose for travelers to high risk areas
• OPV v IPV

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Rabies vaccine

• Generally low risk, area dependent
• 1,882 European travelers in Thailand dog bites
  in 1.3, dog licks in 8.9 in lt 3 weeks
  (Steffan)
• UK 10 /12 cases over 20 years imported from
  India
• USA over 17yrs, 33 were imported
• CDC

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Rabies vaccine

• Pretravel rabies vaccine obviates need for
  (scarce) rabies immunoglobulin in high risk
  exposure
• Indications consider mode of travel, area of
  travel, local rabies epidemiology, access to safe
  and effective post exposure prophylaxis
• Pre exposure vaccine IMI on days 0, 7 and 28
• Post exposure give boosters on days 0, 3 and
  omit immunoglobulin
• Some antimalarials suppress immune response to
  rabies vaccine

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Typhoid vaccines

• Live oral vaccine Ty21a strain, schedule of 4
  doses on alternate days
• Efficacy 63 for 3 years in trials in endemic
  areas. No studies in travelers
• Polysaccharide vaccine Typhim Vi
• Efficacy 72-80 in Nepal, in South Africa
• Indications selected travelers to high risk
  areas
• Acharya NEJM 1987 Klugman Lancet 1987

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Cholera vaccine

• Dukoral? inactivated oral vaccine
• Protects against Vibrio cholerae 01 and ETEC
• Cholera protective efficacy 80-85 for 6
  months, and 63 over 3 years
• ETEC protective efficacy about 60, lasting
  about 3 months
• Indication Travelers to high risk destinations ?

BASRA, IRAQ 2004
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Meningococcal vaccine

• Polysaccharide vaccine A,C,W135,Y AC
• Single dose
• 3 yrs protection
• Indications travelers to the Hajj
• Travelers to countries in meningitis belt
  experiencing outbreaks

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Immunization of immunocompromisedtravelers

• Increased risk of travel related disease
• Potential risk from live vaccines
• Potential increase in adverse reactions
• Decreased vaccine immunogenicity
• Effect on HIV replication

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Vaccine schedules

• Yellow fever and cholera must be given at least
  3 weeks apart
• Inactivated vaccines and live vaccines can be
  given simultaneously
• Antibody responses to live vaccines reduced if
  given with immunoglobulin give live vaccines
  either 2 weeks before or minimum of 6 months
  (ideally 3 months) after immunoglobulin

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The impossible traveler

• 34 year old security worker on contract to Iraq
• Request for smallpox vaccine..