Immunisation

for travel

Conrad Moreira

The Travel Doctor – TMVC Sydney

• Hepatitis A and B ?

• Typhoid ?

• Yellow fever ?

• Cholera ?

• Diphtheria/tetanus/pertussis ?

• Measles/mumps/rubella ?

• Varicella ?

• Influenza ?

• Japanese Encephalitis ?

• Meningitis ?

• Polio ?

• Rabies ?

• Tick-borne encephalitis ?

• Tuberculosis ?

• Dengue?

“What vaccines do I need?”

“What vaccines do I need?”

How could we decide?

• Incidence - Consequence

• “This traveller, this trip, this time”

• “Three Rs”

• Japanese Encephalitis

• Rabies

• Kids / Pregnancy

The travel consultation

• Identify high-risk travellers

• Obtain insight into mental health / resilience

• Raise awareness of risks and preventative behaviours

• Review immune status: recommend relevant immunisation

• Consider prophylaxis

• Prescribe medical kit

Vaccines won’t prevent everything…

DON’T FORGET TO EDUCATE …• Eating and drinking safely (as possible)• Avoiding insect bite• Environment (water, soil, sun, high altitude)• Avoiding animal bite• Substance abuse• Safe sex and BBVs• Injury and personal safety• DVT, barotrauma etc…

The value of common sense

https://blogs.worldbank.org

This traveller…

This trip…

This time

This Traveller

• Age• General health and fitness• Chronic conditions• Medications• Allergies• Immune status…et cetera

This Trip

• Urban/rural/remote• Extremes of climate, altitude• Length of trip/exposure• Purpose of travel: holiday, business, VFR, expatriate• Style of travel: accommodation, transport, dining – affects

“quality” of exposure• Specific or unusual activities: caving, climbing, diving

This Time

• Wet/dry season• Current disease outbreaks• Political unrest• Weather events

What is happening there now? What could be happening at the time of travel?

Keep up to date!

wwwnc.cdc.gov/travel/

Yellow Book

Outbreaks / warnings

https://travelhealthpro.org.uk/

www.fitfortravel.nhs.uk

www.promedmail.org

https://smartraveller.gov.au/

3 ‘R’s of travel vaccination…

REQUIRED

– to cross international borders

ROUTINE

– routine, scheduled immunisations

RECOMMENDED

– to address specific risks of travel

“What vaccines do I need?”

REQUIRED– Yellow fever, meningococcal ACWY*, polio*

ROUTINE – DTP, MMR, Hib, varicella, pneumococcal, hep B*,

rotavirus, polio, HPV, flu, meningococcal ACWY*

RECOMMENDED– Hep A, hep B*, typhoid, cholera, JE, TBE, rabies,

meningococcal ACWY*, BCG

“What vaccines do I need?”

REQUIRED– Yellow fever, meningococcal ACWY*, polio*

ROUTINE– DTP, MMR, Hib, varicella, pneumococcal, hep B*,

rotavirus, polio, HPV, flu, meningococcal ACWY*

RECOMMENDED– Hep A, hep B*, typhoid, cholera, JE, TBE, rabies,

meningococcal ACWY*, BCG

“Routine” vaccines are

important travel vaccines

“What vaccines do I need?”

REQUIRED– Yellow fever, meningococcal ACWY*, polio*

ROUTINE – DTP, MMR, Hib, varicella, pneumococcal, hep B*,

rotavirus, polio, HPV, flu, meningococcal ACWY*

RECOMMENDED– Hep A, hep B*, typhoid, cholera, JE, TBE, rabies,

meningococcal ACWY*, BCG

Jane Doe, 23 yo

• Healthy female, no regular medication, immunised for age • No previous travel

• Travelling with partner for 5 weeks: September-October• 3-4 star hotels in urban centres• Singapore; Cambodia (Seam Reab, Phnom Penh); Vietnam (Ho Chi Minh to

Hanoi); Indonesia (Bali) • About a week in each country

• Mainly sightseeing – usual sites. Will try street food. No trekking• Shopping in Singapore• Angkor Wat, Tonle Sap; Phnom Penh • Mekong Delta, Cu Chi, Hoi An, Hue, Halong Bay• Uluwatu and Ubud

Risk assessment

This traveller

This trip

This time

Hazards?

Future travel???

Does Jane REQUIRE any

vaccines to enter or leave

these countries?

• Cambodia

• Vietnam

• Indonesia

• Singapore

What would you recommend?

Hepatitis A?

Hepatitis B?

Typhoid?

Rabies?

Japanese Encephalitis?

Cholera?

Address the traveller’s concerns as well as the risk

Japanese Encephalitis

Most common vaccine-preventable encephalitis in Asia

Enzootic cycle: birds, pigs and mosquitoes

Transmission seasonal or year-round; varies with latitude

20-30% mortality; Up to 50% residual disability in children affected

Prevalent in areas of rice cultivation, flood irrigation

Transmitted by Culex mosquitoes; mainly active during twilight

Source: CDC Yellow Book 2018

JE and travellers

• Overall risk in travellers to Asia: <1/1,000,000

• Expats, intense exposure: up to 50/100,000/year• This approximates local risk: 5–50 cases per 100,000

children per year

• CDC: • 1973-2017: 84 cases identified in travellers from non-

endemic areas • 1993-2017: 12 cases in US travellers (post-vaccine

licensure)

http://www.nih.go.jp/niid/entomology/picture/tritaeniorhynchus/tritae03.jpg

Culex tritaeniorhynchus

“Nestled within an exclusive estate surrounded by lush

greenery and verdant rice fields…

…villas and suites gracing a five-hectare rural expanse

echoing with cheerful birdsong, paparazzi-free privacy is

assured…”

Australian Immunisation

Handbook

• “JE vaccination is recommended for travellers spending 1 month or more in endemic areas in Asia and Papua New Guinea during the JE virus transmission season, including persons who will be based in urban areas but are likely to visit endemic rural or agricultural areas…

• …It is important to note that, as JE has occurred in travellers after shorter periods of travel, JE vaccination should be considered for shorter-term travellers, particularly if the travel is during the wet season, or anticipated to be repeated, and/or there is considerable outdoor activity, and/or staying in accommodation without air conditioning, screens or bed nets…

• …All travellers to Asia (and other tropical regions) must be fully aware of the need to take appropriate measures to avoid mosquito bites.”

http://www.immunise.health.gov.au/

CDC Yellow Book

• “…recommends JE vaccine for travelers who plan to spend ≥1 month in endemic areas during the JE virus transmission season. This includes long-term travelers, recurrent travelers, or expatriates who will be based in urban areas but are likely to visit endemic rural or agricultural areas during a high-risk period of JE virus transmission. Vaccine should also be considered for the following:

• Short-term (<1 month) travelers to endemic areas during the JE virus transmission season, if they plan to travel outside an urban area and their activities will increase the risk of JE virus exposure…

• Travelers to an area with an ongoing JE outbreak.

• Travelers to endemic areas who are uncertain of specific destinations, activities, or duration of travel.

https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/japanese-encephalitis

JE vaccines

• Inactivated mouse brain-derived• (Korean Green Cross)

• Inactivated Vero cell-derived• Vero cell IC51 SA14-14-2 (IXIARO, JESpect)• Vero cell Beijing (Biken)

• Live attenuated• SA14-14-2 (Chengdu)

• Live recombinant (chimeric)• IMOJEV, ChimeriVax-JE

• Likely to be cheaper overseas (for expats)

JE Vaccination: Australia

• JESpect®:• Can use from 2mths of age• 2-dose primary course: 0 and 28 days• Accelerated course in adults (>=18yo): 0 and 7 days• Booster at 12-24 months• ?further boosting required

• IMOJEV ® : • Can use from 12 mths of age• Single dose in adults• Lower persistence of immunity in young children• Up to 17 years old: booster at 12 months• ?further boosting required

JE: Practice Points

• Low risk, high consequence

• Quality of exposure is important

• Think about recurrent travel

• Awareness of risk and need for bite prevention is usually adequate

• Reassure low-risk travellers but also be sensitive to their perceptions and risk tolerance

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Monkey Business…

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49

50

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Rabies

~26,000-61,000 human deaths/year– 99% due to dogs

Incubation variable, usually 1-3 months– 1-3% become ill >6mths after exposure

– Encephalitic (‘furious”) and Paralytic variants

Human travellers– risk of exposure: 0.4% per month of stay - street dogs, monkeys

– 1990-2012: 48 deaths from imported cases; 45 dog bites

WHO. Technical Report Series 982. 2013

Gautret, Parola. Curr Opin Infect Dis. 2012;25(5):500-506.

Plotkin. Clinical Infectious Diseases 2000;30:4–12

WHO categories of risk

Category 1 No risk Lyssavirus-free

Category 2 Low risk Only rabies-related lyssaviruses circulating in bats or rabies

virus circulating in bats (non haematophagous) and other

wildlife and

Medical care, CCEEVs and other rabies biological products are

easily accessible, and reliable laboratory-based surveillance

data are available.

Category 3 Moderate risk Rabies virus circulates in bats (non haematophagous) and

other wildlife

Category 4 High risk Sustained dog-to-dog transmission of the rabies virus and/or

where vampire bat rabies is reported

Pre- or Post-Exposure Vaccination?

• Animal rabies at the destination• High risk of exposure• Duration or complexity of itinerary

• Availability of PEP– Access to medical facilities– Immunoglobulin / MAb– Cell culture rabies vaccine

• Cost– ?intradermal vaccination– ?vaccinate overseas

Individuals with documented immunodeficiency should

be evaluated on a case-by-case basis and best receive

an ID or IM PrEP schedule as above, plus a third vaccine

administration between days 21 to 28. Additionally, in

the event of an exposure, a complete PEP course,

including RIG, is recommended.

Should you advise the WHO

recommended 2-dose PrEP ???

US CDC (Yellow Book)

https://wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/rabies

UK HPA

Australian Immunisation

Handbook

Pre-exposure prophylaxis (PreP)

The recommended schedule for pre-exposure

prophylaxis (PreP) for rabies or other lyssavirus

infection consists of a total of 3 doses of vaccine; the

1st dose of vaccine is given on day 0, and subsequent

doses on days 7 and 21–28. Although the 3rd dose can

be given as early as 21 days, there are no data to

support the use of an even more accelerated schedule

for those with limited time before travel to a rabies-

enzootic area.

Rabies PrEP: Practice Points

• Is there an unusually high risk of animal bite?

• Difficulty accessing PEP in a timely fashion?

• Will the itinerary make it difficult to adhere to a PEP schedule?

• Is there time to complete PrEP?

• Will there be recurrent exposure?

• What does the traveller want to do?

Child travellers

• May not be fully-immunised

• Vaccines may not be as effective

• Immunologically-naïve

• Immune response may not be as severe

• Higher gastric pH; more rapid gastric emptying – less killing of ingested bacteria

• Animal bites more likely, more severe

• Malaria and TB can be more severe

BCG

• Protective efficacy:– ~50% overall

– ~80% for disseminated TB, TB meningitis and death

• Consider for children <5 years old going for more than one month to a region of high prevalence

Vaccines recommended for travel

Vaccine Lower age limit

• BCG No lower limit

• Rabies No lower limit

• JESpect 2 months

• Men B-ACWY 6 weeks

• Yellow Fever 9 months

• IMOJEV 12 months

• Hep A 12 months

• Typhoid Vi 2 years

• Cholera 2 years

• Typhoid Ty21a 6 years

Travel vaccines in pregnancy

Recommended dTpa

Influenza

Indicated based on risk Hepatitis A

Typhoid Vi

Hepatitis B

IPV

Meningococcal (ACWY, B)

Japanese Encephalitis (inactivated)

Yellow fever*

Contraindicated BCG

Varicella-zoster

MMR

Japanese Encephalitis (live, chimeric)

“Benefits of vaccinating pregnant women

usually outweigh potential risks when the

likelihood of disease exposure is high, when

infection would pose a risk to the mother or

fetus, and when the vaccine is unlikely to

cause harm.”

CDC. Advisory Committee on Immunization Practices. MMWR 2011; 60 (2): 26.

Take away messages

• Educate as well as vaccinate

• Assess risk accurately

• Know what’s happening at the destination

• Know the detail of the trip

• Assess likelihood of exposure

• Consider the consequence for the traveller

• Choose vaccines systematically

• Routine vaccines are also travel vaccines

Thank you

Useful resources

CDC: www.cdc.gov/travel

NATHNAC: https://travelhealthpro.org.uk/

fitfortravel (NHS) : www.fitfortravel.nhs.uk

ProMed: www.promedmail.org

Smartraveller: https://smartraveller.gov.au

Australian Immunisation Handbook: https://immunisationhandbook.health.gov.au/

NCIRS: http://www.ncirs.org.au