2. Epidemiology
➔ HAV transmission is by fecal-oral route
➔ The virus multiplies in the intestinal epithelium and reaches the liver by hematogenous
spread
➔ It is shed in feces during the late incubation period and prodromal face of the illness
➔ Chronic carriers are not seen
➔ Type A Hepatitis occurs sporadically or as outbreaks ( caused by contaminated food ,
water, milk)
➔ Domestic or institutional spread of infection among children is common
➔ Overcrowding and poor sanitation favours its spread
3. ➔ Childrens - no symptoms or non specific symptoms
➔ Adults - 70-75% are symptomatics(<1% mortality)
- Hepatitis A vaccine can be offered to all healthy childrens with special emphasis in high
risk groups
Manifestation
High risk groups
● Patients with chronic liver disease.
● Carriers of hepatitis B and hepatitis C.
● Congenital or acquired immunodeficiency.
● Transplant recipients.
● Adolescents seronegative for HAV who are leaving home for residential schools.
● Travelers to countries with high endemicity for hepatitis A.
4. HIGH ENDEMICITY
Most individuals acquires natural
infection in childhood
Risk of out break/adults acquiring
infection is low
INTERMEDIATE ENDEMICITY
Ex - India (transition from high
endemicity to intermediate
endemicity)
Certain proportion of childrens (50%)
remains susceptible till adult
Risk of HAV transmission still persist
LOW ENDEMICITY
No circulation of virus
Hence the risk of acquiring infection is
low
5. VACCINES
INACTIVATED VACCINE
HM175/GBM strain :
➔ Grown on MRC-S human diploid cell lines
➔ Formalin inactivated and adjuvated with aluminium
hydroxide
RG-SB strain :
➔ Grown on MRC-S human diploid cell lines
➔ Formalin inactivated and adjuvated with IRIV
{immunopotentiating reconstituted influenza
virosome}
STORAGE:
➔ 2-8 °C
➔ Protect from light
➔ Use with in 30 min of reconsition
LIVE ATTENUATED VACCINE
H2 strain :
➔ Grown on KMB-17 cell line
➔ 2-8°C
➔ Do not freeze
➔ Use with in 30 min of reconsition
6. INACTIVATED VACCINE
AVAILABILITY :
● Monovalent
● Polyvalent
a ) Hep A /Hep B
b) Hep A / Vi-polysaccharide (thyphoid)
DOSAGE :
● <18 yrs - 0.5 ml
● > 18 yrs - 1ml
SITE ;
● Intramuscular (deltoid)
LIVE ATTENUATED VACCINE
● Monovalent
● <15 yrs - 0.5ml
● >15 yrs - 1ml
● subcutaneous
7. SCHEDULE ;
● Minimum age for administration is 12 months (<12 months immunogenicity is low )
DOSE -1
6-18 Months
DOSE -2
● WHO recommends single dose administration for live attenuated vaccine
CATCH UP :
AGE
<10yrs >10 yrs
Prevaccinaton
screening for HAV -Antibody as 50% of i
individuals above this are sero positive
2 dose schedule
8. ANTIBODY TITRES
>20 IU/ml
<20 IU/ml
Reactive ( sero positive ) Non reactive
(seronegative)
No need for vaccine 2 dose schedule
INACTIVATED VACCINE
Protection :
● 90-95% protection
● High efficiency in both pre-post exposure prophylaxis
Adverse reactions :
● Local pain
● Head ache
● Malaise
LIVE ATTENUATED VACCINE
● 100% in pre exposure
● 95% in post exposure prophylaxis
● But cannot be used during outbreaks
●
● Soreness
● Erythema
● Fever , malaise
9. INACTIVATED VACCINE
Contra indication:
● Anaphylaxis after previous dose
LIVE ATTENUATED VACCINE
● Hypersensitivity to egg protein
● Immunodeficiency
● Chemotherapy or radiotherapy
Duration of protection
● Long lastin , probably life long
