Adult vaccination

Dewald SteynDepartment of Internal

MedicineUFS

When to vaccinate?

1. Routine - children2. High risk groups - adults3. Travel – both children & adults

Smallpox in the 18th century

• Most feared & greatest killer – It killed 10% of the

population– rising to 20% in towns

and cities

• Among children– it accounted for 1 in 3 of

all deaths

• Touched every section of society “Speckled Monster”

Edward Jenner • vaccination with

cowpox prevented the deadly smallpox

1749-1823

VARICELLA IN ADULTS• 15 x higher mortality

• Pneumonia– 1 to 2% of healthy adults

– Immunocompromised adults

– 10 to 20% of affected pregnant women develop varicella pneumonia

• mortality of up to 41%

Recommendations for varicella vaccine

• All susceptible immuno-compromised individuals– who have retained a moderate degree of immune

function• Women in the childbearing age group who never had

chickenpox • All susceptible healthcare workers • Healthy adults who are exposed to children• Dose – live attenuated vaccine

– > 1 year (single dose)– > 13y (2 doses, 1 month apart)

Varicella Post-exposure prophylaxis:

1. VZIG 6ml (3 ampoules) given imi – to all pregnant women or immuno-suppressed patients

• who are exposed to varicella and who may lack antibodies to the virus (only 25% are truly susceptible)

– as soon as possible after exposure• even up to 96 hours after exposure

– the primary indication for VZIG in pregnant women is to prevent complications of varicella in the mother, rather than to protect the foetus

Varicella Post-exposure prophylaxis:

2. Post-exposure administration of ACYCLOVIR– Effective in aborting VZV infections provided that the

timing is correct– must be given relatively late in the incubation period - 7

to 9 days after exposure

3. VARICELLA VACCINE – healthy individual within about 48 to 72 hours

after an exposure– you can prevent varicella

• Given within 36 hours: 90% chance of preventing varicella• Given within 72 hours: 75% chance of preventing varicella

Prevention of Zoster

• Risk to develop zoster – vaccinees < natural

infection• if you prevent

varicella, you prevent rash on the skin, you prevent entry of virus into the nervous system

cell-mediated immune response

Rabies + Tetanus

• 100% FATAL but also • 100%

PREVENTABLE– Human rabies

immune globulin (HRIG)

– Human diploid cell vaccine

• Tetanus toxoid /TIG

Meningoccal Prophylaxis• Antibiotics

– Household contacts– Kissing contacts

• preceding 10 days– Rifampicin – 600mg b.d x 2 days– Ciprofloxacin – 500mg stat– Ceftriaxone – 250mg stat

• Vaccine (2 weeks before protective Ab)– Groups A, C, Y, W135

• Military camps• Travelers (Africa menigococ belt or Mecca)• Splenectomised pts, complement deficiency

Pneumococcal vaccine

• 23-valent: Prevention of bacteremic disease– ability to prevent meningitis or pneumonia is

unproved• its overall efficacy against pneumococcal meningitis

is assumed to be about 50%• 7-valent conjugate vaccine

– 97.4% efficacy in preventing invasive pneumococcal disease including meningitis from the 7 serotypes of pneumococci in the vaccine

– and 93.9% efficacy in preventing invasive disease from all pneumococcal serotypes

Age-specific Mortality Due to

Hepatitis AAge group

(years)Case-Fatality(per 1000)

<5

3.05-14 1.6

15-29 1.630-49 3.8>49 17.5

Total 4.1Source: Viral Hepatitis Surveillance Program, 1983-1989

Geographic Distribution of HAV Infection

Anti-HAV Prevalence

HighIntermediateLowVery Low

Hep A in unprotected travelers

• 10 - 100 times > typhoid

• 1000 times > cholera

Who should be vaccinated against HepA?

• nursing staff and healthcare workers in contact with patients in children's wards, infectious diseases wards, emergency rooms and intensive care units

• day-care centre staff particularly where children have not been toilet trained

• staff and residents of homes or institutions • sewerage workers • food handlers • homosexual men • people in contact with an infected person • chronic liver disease or liver transplants, or people who receive

certain blood products • travellers to areas with a high incidence of hepatitis A

 

Hepatitis A vaccination?

• On average, adults with hepatitis A miss 30 days of work or routine daily activity.

• Although rare complications do occur!

Hepatitis B is 100 times more infectious than HIV

Virus can survive for up to 7 days on contaminated objects outside the body

Geographic Distribution of Chronic HBV Infection

HBsAg Prevalence8% - High

2-7% - Intermediate <2% - Low

Who should be vaccinated against Hepatitis B

• Spouses and family members of infected persons• Sexual promiscuous persons• HIV positive patients, IV drug users• Health care workers• Hemophiliacs and. Pts on haemodialysis• Residents and staff at institutions for mentally retarded

patients, prisoners• All neonates and non-immune children at 11–12y• Contact sportsmen• International travelers > 6 months to high endemic area

Protective Antibody level?

• Anti-HBs > 10 IU/L• Need for

booster dose? – (7 to 10years)

Combination vaccine

• TwinrixR

– 720 EL.U inactivated hepatitis A virus and – 20 g HBs antigen

– 0, 1, 6 month schedule• Twinrix Adult: > 16 years - 1ml• Twinrix Junior: < 15 years – 0,5ml

Live attenuated intranasal vaccine (LAIV) - FluMist

• intranasal trivalent, cold-adapted LAIV– recently approved in the US– persons aged 5 - 49 years

• 2 influenza A viruses and 1 influenza B virus

Avian Flu

• H7N7 is unrelated to • avian influenza virus currently in Asia

(H5N1) • and the avian influenza reported in

chickens with no human cases in the United States (H5N2)

Other possible prophylaxis

• Oseltamivir (TamifluR)– Prophylaxis of Influenza (>13 years)

• 75 mg o.d

– Treatment of Influenza (>13 years)• Initiate within 48 hours• 75 mg b.d

• Zanamivir (RelenzaR)• 10 mg inhalations b.d for 5 days

Health Advice for International Travel

• General Considerations– Where to ?– When ?– Duration of stay ?– Reason for travel ?– Medical History:

• Illness, Drugs, Allergy, Pregnancy– Immunizations

Advice on disease Prevention

• Travelers’ diarrhea• Malaria• Dengue fever• Schistosomiasis• STD’s• Jet lag, Motion sickness, Sun protection, Acute

mountain sickness, Chronic illness, Pregnancy, HIV

- Myth 1: Not taking Malaria prophylaxis

• highly irresponsible– parasites can multiply at phenomenal rates– malaria can quickly get out of hand

• you will always be able to make the diagnosis – symptoms will present with the same intensity– time to progress to severe malaria may be longer

• repeated blood smears• new antigen-assay tests

- Myth 2

“Prophylaxis need only be taken while in a malaria area”

The drugs work on The drugs work on the parasite once it the parasite once it enters the enters the bloodblood This does not occur This does not occur until until 10-14 days after 10-14 days after being bittenbeing bitten

Malanil® is the Malanil® is the only exceptiononly exception

- Myth 3

• 'the silent killer‘

• she does not buzz around your head at night

“ “ I wasn't bitten, I wasn't bitten, so can I stop so can I stop taking my taking my prophylaxis”prophylaxis”

Insect repellents• DEET

– The American Academy of Paediatrics recommends ≤ 10% for children < 12 y

• Citronella oil – less active than DEET – shorter acting

• must be reapplied every 40-90 minutes

• Bathing, showering, sweating– Re-apply more frequently after

Insecticide-treated nets (ITNs)

• < 5 years– all-cause mortality: <

20%– < 0.5 million deaths / year

in Sub-Sahara Africa • Pregnant women

– protected by ITNs every night during their first 4 pregnancies

– 25% < underweight or premature babies

- KenyaWHOWHO

NOT RECOMMEDED NOT RECOMMEDED

• Chloroquine resistance Chloroquine resistance

• Low Efficacy (60%)Low Efficacy (60%)

1. Mefloquine• 250mg = 1 tab

– 1 week before– weekly in the area– weekly for 4 weeks after

leaving the area

• Restrict use to 1 year• With food

MefloquineNot recommended Not recommended

< 3 months< 3 months < 5 kg< 5 kg 11stst trimester trimester

Dose: Dose: • 5 – 20 kg: ¼ tablet5 – 20 kg: ¼ tablet• 21– 30 kg: ½ tablet21– 30 kg: ½ tablet• 31- 45 kg: ¾:tablet31- 45 kg: ¾:tablet• > 45 Kg: adult dose> 45 Kg: adult dose

Mefloquine• 1 in 10 000

– serious (never again)• 1 in 100

– severe (will not tolerate)• 1 in 20

– minor (may not tolerate)

• Well tolerated by children

Side EffectsSide Effects

• mental illness or mental illness or epilepsyepilepsy• prolongation of the prolongation of the QTc intervalQTc interval

2. Atovaquone-proguanil - Malanil®

• efficacy: 98%• very well tolerated • One dose per day

– 1 to 2 days before– daily in area – for 7 days after return

• Most expensive

MALANIL® Dosage in Prevention of Malaria

Adults: One MALANIL® /

MALARONE® Tablet adult strength = 250 mg

atovaquone/100 mg proguanil

Pediatric Patients: dosage based on body weight

MALANIL®

Atovaquone-proguanilDosage for Prevention of Malaria

in Pediatric Patients

Weight (kg) Total Daily Dose Dosage Regimen

11-20 62.5 mg/25 mg 1 Pediatric Tablet daily

21-30 125 mg/50 mg 2 Pediatric Tablets daily

31-40 187.5 mg/75 mg 3 Pediatric Tablets daily

>40 250 mg/100 mg 1 Adult Strength Tablet daily

3. Doxycycline • not < 8 years• not for pregnancy• >15y or >45 kg

– 100mg /d• >8y or 31kg

– 3mg/kg• Daily• highly effective • short term use• photosensitivity • birth control

Advantages and disadvantagesMefloquineMefliam®, Lariam®

DoxycyclineDoximal®, Doxitab® or other

Atovaquone-proguanilMalanil®

Avoid with neuropsychiatric or epilepsy history Avoid in porphyria

Not specifically contraindicated with neuropsychiatric disorders

>5 Kg not for < 8 years >11 Kg40 kg RSA

Pregnancy: Yes (2nd Trim)

Pregnancy: NO pregnancy ?

Vivid dreams and nightmares and insomnia

Gastro-esophageal irritation Diarrhea

Mood alterations in susceptible individualsDizziness and nauseaOnce weekly dosageShould start at least one week before departureShould be taken for four weeks after returnInexpensive

Skin photosensitivity(3% in one study)Candida super infectionDaily dose + for 4 weeks after returnUseful in areas of mefloquine resistanceInexpensive

Drug rash (uncommon)Nausea and vomitingOnce daily dosageShould start 2 days before departureShould be taken for 7 days after returnMost expensive

MefloquineMefliam®, Lariam®

DoxycyclineDoximal®, Doxitab® or other

Atovaquone-proguanilMalanil®

AdvantagesAdvantages and disadvantagesand disadvantages

continuecontinue

ADULTS

MefloquineMefliam®, Lariam®

DoxycyclineDoximal®, Doxitab®, other brands

Atovaquone-proguanilMalanil®

Efficacy 95% Score = 3

95% Score = 3

95% Score = 3

Tolerance Occasional disabling SEScore = 1

Rare disabling SEScore = 2

Rare minor SEScore = 3

Convenience Weekly dosingScore = 3 + 1

Daily dosingScore = 2 -1

Daily dosingScore = 2

After leaving the area

Need to be taken for 4 weeks Score = 0 + 1

Need to be taken for 4 weeks Score = 0

Need to be taken for 7 days Score = 2

Cost

Score = 2 Score = 3

R 500 for 12 tabs

Score = 1 –1

Total 11 9 10

MefloquineMefliam®, Lariam®

Atovaquone-proguanilMalanil®

DoxycyclineDoximal®, Doxitab®, other brands

Efficacy 95% Score = 3

95% Score = 3

95% Score = 3

Tolerance Occasional disabling SEScore = 1 + 1

Rare minor SEScore = 3

Rare disabling SEScore = 2 - 2

Convenience Weekly dosingScore = 3 + 1

Daily dosingScore = 2

Daily dosingScore = 2

After leaving the area

Need to be taken for 4 weeks Score = 0 + 1

Need to be taken for 7 days Score = 2

Need to be taken for 4 weeks Score = 0

Cost

Score = 2 - 1

R 500 for 12 tabs

Score = 1 Score = 3

Total Children 11 10

Not < 8y8

• If the child vomits within 1 hour after oral dose, the dose must be repeated

Stand by therapyStand by therapy

Traveler's Diarrhea

• This is the most common health problem to affect travelers– 80% is bacterial, typically acquired from contaminated food or water

• Attack rates among travelers to the Caribbean, southern Europe, Israel, Japan, and South Africa range from 8% to 20%.

• Attack rates are as high as 60% within 2 weeks of travel to Mexico, the Middle East, Asia, and the developing countries of Africa and Central and South America. [1]

• affects 20% to 50% of persons who travel to tropical and semitropical areas, including Latin America, parts of the Caribbean, southern Asia, and Africa

• Watery diarrhea, caused primarily by enterotoxigenic Escherichia coli, affects as many as 60% of short-term travelers and is characterized by explosive, nonbloody stools with nausea, vomiting, abdominal cramping, and fever

• Fortunately, most of these cases are self-limited to a duration of less than 1 week.

Travel Medicine Resources

• www.cdc.gov/travel• http://travel.state.gov

• http://wwwn.cdc.gov/travel/contentYellowBook.aspx