Hepatitis A Vaccine - Pediatric Oncall

HEPATITIS - A VACCINE - LATEST UPDATES

Live Hepatitis A vaccine is now available that is to be given subcutaneously after 1 year of age. The international vaccine was first developed by Dr Mao, the main inventor of the vaccine in the year 1987 and introduced in China in 1992. Till date over 120 million people have been administered the vaccine successfully in China. This new generation vaccine offers long term protection and convenience of a single dose administration for both adults and children. There is no need for a booster dose with this vaccine. The vaccine is now available in India and is packaged as a vial of the freeze-dried, live attentuated lyophilised vaccine along with 1 ml of diluent for a single dose.
Accelerated Schedule: A randomized multicentric study from Germany conducted that accelerated schedule (Combined Hepatitis A & B at 0, 7, 21 days or Hepatitis A on day 0 and Hepatitis B vaccine on D0, D7 and D21 with booster at 12 months) provides a good immune response against Hepatitis A & B antigens and is suitable for last minute immunization.
A study from Israel reported that rectal immunization might be highly effective way of inducing both local and systemic immunity to Hepatitis-A virus (In animal model).
Hepatitis A Vaccine and Cirrhosis: Study from USA suggest that seroconversion after Hepatitis A vaccination was significantly less in decompensated liver disease and the presence of advanced disease (Child - Pugh Class B/C). These findings indicate that the response to Hepatitis A vaccination in chronic liver diseases is optimal when targeted to patients before the development of hepatic decompensation.
Hepatitis A Vaccination and HCV carriers: Recent study suggested that Hepatitis A vaccination should be considered in all patients positive for HCV infection.
Hepatitis A Vaccination - whether booster in needed? Data have shown that after a full primary immunization course protective antibodies persist for more than 10 years in healthy individuals and underlying immune memory provides protection far beyond the duration of anti HAV Antibodies. So it can be concluded that there is no evidence to lend support to HAV booster vaccination after a full primary vaccination course in healthy individuals. However for special patient groups further research is needed.
Post exposure prophylaxis: Study from Italy showed that post exposure administration of currently available immunoglobulin is effective in preventing Hepatitis A infection and disease. Active immunization with Hepatitis A vaccine to secondary contacts of exposed subjects should be offered.
Mother to Newborn transmission: Unlike Hepatitis B, mother infected with Hepatitis A rarely transmits the disease to their newborns

With the availability of vaccine, it is pertinent to consider its use in the effective control of the disease. However with the varied epidemiological patterns and economical constraints in different countries, it does not seem to be possible to evolve universal policy for immunization. Though universal immunization may be the most effective way of control, the same is not practical for many countries.

WHO position on Hepatitis A Vaccines:

The currently available vaccines against Hepatitis A are all of known good quality and in line with the WHO recommendations.
They are licensed for use in children more than one year of age because of interference by passively acquired maternal antibodies in children less than one year.
In countries where Hepatitis A is highly endemic, exposure to Hepatitis A is almost universal before the age of 10 years. In such countries, clinical Hepatitis A is usually a minor public health problem, and large-scale immunization efforts against this disease should not be undertaken.

References:

Ren A, Feng F; Ma J; Xu Y; Liu C. Immunogenicity and safety of a new inactivated hepatitis A vaccine in young adults: a comparative study. Chin Med J (Engl) 2002;115(10):1483-5.
Guptan RC, Thakur V, Safary A; Sarin SK. Immunogenicity and reactogenicity of a combined high dose hepatitis A and hepatitis B vaccine, compared to that of Twinrix in healthy Indian children. Vaccine 2002;20(16):2102-6.
Arankalle VA, Chadha MS. Who should receive hepatitis A vaccine? J Viral Hepat 2003;10(3):157-8.
Mitchell LA, Galun E. Rectal immunization of mice with hepatitis A vaccine induces stronger systemic and local immune responses than parenteral immunization. Vaccine 2003;21(13-14):1527-38.
Arguedas MR, Johnson A, Eloubeidi MA, Fallon MB. Immunogenicity of hepatitis A vaccination in decompensated cirrhotic patients. Hepatology 2001;34(1):28-31.
Core information for the development of Immunization Policy. WHO- Vaccines and Biologicals. 2002 Update
Sans M, Escorza S, Villagrasa D et al. Carriers of hepatitis C: should they all be vaccinated for hepatitis A? Aten Primaria 2002;30(2):80-4.
Nothdurft HD, Dietrich M, Zuckerman JN et al. A new accelerated vaccination schedule for rapid protection against hepatitis A and B. Vaccine 2002;20(7-8):1157-62.
Van Damme P, Banatvala J, Fay O et al. Hepatitis A booster vaccination: is there a need? Lancet 2003;362(9389):1065-71.
Taliani G, Gaeta GB. Hepatitis A: post-exposure prophylaxis. Vaccine 2003;21(19-20):2234-7.

Last Updated on 01-3-2006 Courtesy Pediatric Oncall

HEPATITIS - A VACCINE

1). Which are the hepatitis -A vaccines available?
1). There are 2 types of Hepatitis A vaccines available. Killed inactivated vaccine contains HM 175 strains of Hepatitis A virus grown on human diploid cell culture originally obtained from the fecal sample of patients from Melbourne, Australia. A new freeze dried live attenuated vaccine is now available that is made from master seen virus , the H2 attenuated strain of HAV cultured in human diploid cells. 5 vaccines are available currently- Biovac A (Internationally - Zhepu), Havrix, Avaxim, Vaqta and Epaxal. Only the first 3 brands are available in India .

BIOVAC A is single dose of 1.0 ml to be administered subcutaneously .

Havirix is available in two forms for pediatric use, as 360 EU per dose in 0.5 ml ready to use suspension, and 720 EU per dose in 0.5 ml suspension. Adult vial contains 1440 EU in 1.0 ml volume.

Vaqta is available for pediatric use containing 25 U/ dose and adult dose containing 50 U/dose.

Pediatric use means till 19 years of age and adult dose > 19 years of age.

2). What is the schedule of giving Hepatitis A vaccine?

2). The dose and schedule differ with the 3 vaccines.

BIOVAC A is single dose to be administered subcutaneously in a child above 1 year of age.

Havirix in children can be given in 2 schedules. First schedule consists of 3 doses of 360 EU at 0, 1 and 6-12 months and second schedule of 2 doses of 720 EU at 0 and 6 - 12 months. It is to be given intramuscularly in the deltoid region.

Vaqta in children is given as 2 doses of 25 U at 0 and 6- 12 months.It is to be given intramuscularly in the deltoid region.

3). How are the Hepatitis - A vaccines stored?
3). The vaccines are stored at 2-8⁰ C in refrigerator.

4). What are the side effects of hepatitis - A vaccine?
4). The side effects of Hepatitis A vaccines are very rare and mild. Local side effects seen include redness, swelling and pain at injection site. They usually subside in 72 hours. Systemic side effects like mild fever, headache, malaise, arthralgia and gastrointestinal disorders may be seen.

5). When is Hepatitis A vaccine contraindicated?

5). Patients known to have hypersensitivity to the vaccine or any component of the formualtion should not be given the vaccine. It is also contraindicated during pregnancy and in patients with fever. Live vaccine should be avoided in immunocompromised patients. Patients with history of anaphylaxis to vaccines should avoid the vaccine.

6). What is the efficacy of each vaccine?
6) Among the killed vaccine it is found that antibody titres rise by 2nd week after first dose in over 85% of children and in 95% of children by the end of the first month. After the second dose (in 3 dose schedule), 97% have protective titres and after the third dose, 100% have protective titres. One year after completion of vaccination the titres fall gradually however Kinetic models developed have suggested that titres are likely to remain in protective range for at least 20 years after vaccination.

Live vaccine: A study in 3089 adult healthy individuals suggested that seroconversion occurs in 2-5 weeks after the injection and was seen in 95.6% of individuals. Another study in 3031 children aged 6 to 9 years found the seroconversion rate to be 97.5% after 4 weeks of inoculation. The protective efficacy of this vaccine was found to be 94.47% in randomised and controlled trials in 12036 children.

7). Who should be receive Hepatitis A Vaccine?
7)Though Hepatitis-A is a self limiting disease, there is no effective treatment. In addition there is occasional mortality due to fulminant hepatitis especially in adolescent and adults.Thus primary immunization may be recommended for pre-exposure prophylaxis in individuals who are at increased risk of the infection such as -

Foreign traveller : Those staying in low endemic areas for Hepatitis A do not develop natural immunity till adulthood. Such persons are at risk of developing Hepatitis A when they visit an area with high endemicity. If such a person is going to stay for <3 months, Hepatitis A immunoglobulin can be enough to prevent hepatitis-A. If the stay is going to be prolonged it is better to give the vaccine.
Patients with chronic liver disease who may be at increased risk of fulminant hepatitis A.
During epidemics: Whenever there is an outbreak of Hepatitis A in a community
IV drug abusers
Those who have occupation hazards like staff working in laboratories, food handlers, health personnel, zoo keepers, veterinarians, emergency relief workers and members of armed forces.
Those who work in day-care centers or schools or institutionalized children etc.

Children from a higher socio-economic group who may not have had natural infection may be given the Hepatitis A vaccine.

8) Can hepatitis-A vaccine be given along with other vaccines?
8) Yes, hepatitis-A vaccine can be given along with any other vaccine provided one uses separate syringes and separate sites for different vaccines.

Last created on 23-02-2001
Last updated on 01-12-2004

How to cite this url

Dr.Shah N.Hepatitis A Vaccine.Pediatric Oncall [serial online] 2004 [cited 2004 December 1];1. Available from:


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