07/09/60

Updates on Yellow Fever Vaccination

Watcharapong Piyaphanee MD, Board Int Med, CTH™, Dip Trav Med, MFTM RCPS (Glasgow) Travel Medicine Research Unit Department of Clinical Tropical Medicine Faculty of Tropical Medicine, Mahidol University

Content

Introduction to yellow fever Yellow fever vaccine Current international regulation Current yellow fever outbreak

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Yellow fever endemic area

Source: who.int

Yellow fever

Is a mosquito borne disease, particularly Aedes or Haemagogus spp. Nonhuman and human primates are the main reservoirs of the virus 43 Countries in Africa, South and Central America are endemic area for yellow fever 800 million people live in yellow fever risk area Approx 130,000 yellow fever cases and 44,000 deaths reported annually in Africa

CDC Health Information for International Travel 2014 World Health Organization (WHO) 2 07/09/60

Yellow fever

Incubation period usually 3-6 days Most infections likely to be asymptomatic Severe case: fever, jaundice, renal failure and multiorgan failure  death Case fatality rate in severe case is 20-50% No specific treatment

CDC Health Information for International Travel 2014 World Health Organization (WHO)

Yellow fever endemic area

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Risk to travelers

For a two weeks stay: Risk of illness and risk of death are: – West Africa are 5 per 10,000 and 1 per 10,0000 respectively – South America are 5 per 100,000 and 1 per 100,000 respectively

During 1970-2011: – 9 cases of yellow fever among travelers reported – 8/9 travelers died

CDC Health Information for International Travel 2014 4 07/09/60

Colebunders R, et al. CID 2002: 35, e113

Yellow fever vaccine

Live attenuated vaccine More than 900 million doses used Excellent safety and efficacy Need to receive 10 days before travel Routinely used in endemic country Immunity from vaccine – long lasting*

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Vaccine for travelers

Required vaccine (Mandatory)  Yellow fever vaccine, Meningococcal vaccine (for Hajj, Umrah)

Routine vaccine  DTP, MMR, JE, HepB, Polio, BCG

Recommended vaccines for travelers • Hepatitis A,B vaccine • Rabies vaccine • JE vaccine • Typhoid vaccine • Meningococcal vaccine • Cholera vaccine

Contraindication of YF vaccine

Children ≤ 6 months Patient with thymus diseases Allergic to vaccine component Immunocompromised host – Symptomatic HIV or CD4<200 – On immunosuppressive therapy – Primary immunodeficiency – Malignant neoplasm – Transplantation 6 07/09/60

Precaution of YF vaccine

Children ≤ 9 months Age ≥ 60 years Pregnancy Breastfeeding Asymptomatic HIV CD4 200-499

Serious adverse reactions

Yellow fever vaccine associated viscerotropic disease (YEL-AVD) – Severe illness similar to wild-type diseases – Disseminated viral infection with multiple organ failure – All cases occur in first time vaccinee – Risk 0.4 per 100,000 dose1 1 per 100,000 dose in people 60-69 yrs1 2.4 per 100,000 in people >70 yrs2 – Mortality rate >60%2

1CDC Health Information for International Travel 2016 2 WHO – International Travel and Health 2014 7 07/09/60

Vaccine 2005; 23:3256–3263.

Risk of YEL-AVD 8 07/09/60

Fatal myeloencephalitis following yellow fever vaccination in a case with HIV infection.

Kengsakul K, Sathirapongsasuti K, Punyagupta S

A 53 year old physically healthy man, unaware of any immunocompromised condition developed rapidly fatal myelomeningoencephalitis following a live- attenuated yellow fever vaccination. He was found to have asymptomatic HIV infection with high viral loads and low CD4 counts. This is the first reported case of such an incidence in the world literature. It is strongly suggested that in countries where HIV infection is endemic, an HIV blood test should be performed prior to the yellow fever vaccination and the vaccine should not be given to those immunocompromised persons

J Med Assoc Thai. 2002; 85(1):131-4. 9 07/09/60

Serious adverse reactions

Yellow fever vaccine associated neurologic disease (YEL-AND) – Present as meningitis/encephalitis/GBS/ADEM or other neurological deficit – Mainly seen in infant, so YF vaccine is contraindicated in children <6 month – Risk 0.8 per 100,000 dose 1.6 per 100,000 dose in people 60-69 yr – Almost all cases occur in first time vaccinee – Rarely fatal

CDC Health Information for International Travel 2016

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Yellow fever certificate

(Yellow book)

Yellow fever certificate

Must be issued in authorized vaccination center only Valid life long* (Previously 10 years before June 2016) One certificate for one person no correction/amendment on this book

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Validity of YF vaccine certificate

May 2014, WHO’s Strategic Advisory Group of Experts on immunization that

a single dose of yellow fever vaccine confers life-long protection

IHR 2005 : Annex 7 – Amend yellow fever vaccine certificate to valid for life Enforced on 11 July 2016

Theoretically, yellow fever vaccine certificate should valid for life time

But it is uncertain when and if all countries with current yellow fever vaccination entry requirements will adopt this change. CDC Health Information for International Travel 2016

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YF vaccine

Is this trip including yellow fever risk area? Is it required by international law/regulation? Is there any contraindication/precaution of YF vaccine?

Yellow fever endemic area

CDC Yellow book 2016 13 07/09/60

Common problem

Am I really need yellow fever vaccine for Brazil? – Some say yes – Some say no

If I visit only Rio de Janeiro, do I need a shot?

CDC Yellow book 2016 14 07/09/60

ประเทศทีเป็นเขตติดต่อของโรคไข้เหลือง* ทวปี อเมริกา บราซิล(Brazil), โบลิเวีย(Bolivia), เปรู(Peru), เอกวาดอร์(Ecuador),กายอานา กลาง-ใต้ 13 (Guyana), เฟรนซ์เกียนา(French-Guiana), ปานามา(Panama), โคลอมเบีย ประเทศ (Colombia), เวเนซูเอลา(Venezuela), ซูรินาเม(Suriname), ตรินิแดดแอนดโ์ ตเบโก (Trinidad and Tobago), อาร์เจนตินา(Argentina), ปารากวยั (Paraguay)

ทวปี แอฟริกา 32 แองโกล่า(Angola), เบนิน(Benin), บูร์กินาฟาโซ(Burkina-Faso) บุรุนดิ (Burundi), ประเทศ แคเมอรูน (Cameroon), สาธารณรัฐแอฟริกากลาง(Central African Republic), สาธารณรัฐคองโก(Republic of Congo) โกตดิววั ร์(Cote D’Ivoire), เอธิโอเปีย (Ethiopia), แกมเบีย(Gambia), กาบอง (Gabon), กานา(Ghana), กินี(Guinea), กินี บิสเซา(Guinea-Bissau), อิเควทอเรียลกินี(Equatorial Guinea), เคนยา(Kenya), ไลบีเรีย(Liberia), มาลี(Mali), มอริเตเนีย(Mauritania), ราวนั ดา(Rwanda), เซาโตเม และปรินซิเป(Sao Tome & Principe), เซเนกลั (Senegal), เซียร์ราลิโอน(Sierra Leone), โซมาเลีย(Somalia), ซูดาน(Sudan), ชาด(Chad), โตโก (Togo), อูกนั ดา (Uganda), แทนซาเนีย (Tanzania), สาธารณรัฐประชาธิปไตยคองโก (Democratic Republic of Congo) ไนเจอร์(Niger), ไนจีเรีย(Nigeria)

* ตามประกาศของกระทรวงสาธารณสุข

Yellow fever area as declared by each countries

Country Africa Latin America

WHO, US CDC 30 13 Australia 30 13 China 29 13 Thailand 32 13 Saudi Arabia 29 13 Singapore 30 13

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Yellow fever endemic area

CDC Yellow book 2016

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Case Scenario

70 years old couples plan to visit Kenya for 2 week for safari and ask for yellow fever vaccine.

They have never get yellow fever vaccine before

Risk of serious adverse event?

Risk of YFL-AVD (US CDC) • General population 4 in 1,000,000 • 60-69 years 1 in 100,000 dose • >70 years 2.3 in 100,000 dose Or 1 in 50,000 dose

Risk = 1: 50,000 Is it High or Low? Is it acceptable?

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Risk Perception

Everyone looks at the same risk differently Risk tolerance differs from man to man Travelers’ peace of mind must be considered

Pre-travel visit must be individualized – Risk communication – Risk perception and risk tolerance – Risk management

Yellow fever in Brazil 2017

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Yellow fever in Brazil 2017

Yellow fever in Angola 2016

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Yellow fever situation in Africa

Routine childhood vaccination implemented 35 out of 42 endemic countries Vaccine coverage is poor In 2015 Nigeria had only 40% coverage Cost and supply of vaccine remain a problem

Yellow fever outbreak in Angola

72% vaccine coverage among children aged 9 months Jan – July 2016 – 3818 suspected cases (875 confirmed) – 369 death – YF spread to DRC Congo; 2051 cases/95 deaths – 2 YF cases identified in Kenya – 11 YF cases identified in China

BMJ 2016;354:i4559 doi: 10.1136/bmj.i4559 20 07/09/60

11 imported YF cases from Angola to China

J Infect. 2016. pii: S0163-4453(16)30164-5. doi: 10.1016/j.jinf.2016.07.003

YF vaccine shortage

WHO has around 6 million doses of YF vaccine reserved for emergency Certainly not enough to halt the outbreak in Angola and DR Congo WHO expert group suggest the use of 1/5 doses (0.1ml) and it can give protection but the duration of protection may be not life-long

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Conclusion

YF is an international heath problem Asia is a potential area that might have YF spreading Travelers to yellow fever risk area should be vaccinated International regulation/control should be strengthening

Thank you for your attention

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