Hepatitis a prophylaxis - Vaccine or immunoglobulin?

Hepatitis A virus (HAV) infection, once endemic in children in most continents and usually asymptomatic, is now declining. As a result, more and more adult populations worldwide are becoming susceptible to HAV infection, which is frequently symptomatic and disabling in those above 12 to 15 years of age. Traditionally, serum immunoglobulins containing high-titre antibodies to HAV (anti-HAV) have been used effectively during the past 50 years for post- or pre-exposure prophylaxis. However, decreasing prevalence of individuals with anti-HAV has led to a worldwide decline in anti-HAV titres in blood donors and, as a result, to a shortage of immunoglobulin. Meanwhile, several excellent vaccines have been developed from attenuated HAV propagated in tissue culture and inactivated by formaldehyde. These vaccines are highly efficacious and immunogenic, and so far have an excellent record of safety and tolerability. Currently, a single dose of these HAV vaccines will prime the immune system in children and young adults, affording rapid protection against clinical HAV-induced disease within 3 to 5 weeks of administration and lasting for more than 6 months. Booster doses will prolong protection for several years. To date, some federal health agencies believe that cost-benefit analysis still favours immunoglobulin administration over active immunisation for hepatitis A prophylaxis. However, once the cost of the new vaccines drops, immunisation is expected to gain worldwide acceptance by national healthcare authorities. Available data already suggest that 2 to 3 doses of the new vaccines will provide long term immunity against HAV, thus reducing the discomfort and unknown long term risks associated with immunoglobulin injection. Thus, regardless of economic considerations, travel medicine experts and primary core physicians in most Western countries recommend active immunisation against HAV for individuals at risk if they can afford to cover the cost.