From the Research
Hepatitis A vaccine boosters are recommended for elderly individuals who have completed the initial vaccination series and are planning to travel to areas endemic for hepatitis A, as the immune response decreases with age and a booster dose can provide optimal protection. The standard hepatitis A vaccine series consists of two doses given at 0 and 6-12 months, which typically provides long-lasting immunity for most people. However, for elderly individuals, the immune response to the vaccine may be reduced, and a booster dose may be necessary to ensure optimal protection 1. A study published in 2006 found that a booster dose of hepatitis A vaccine in elderly individuals over 50 years old resulted in a seroprotection rate of 98%, compared to 65% after a single primary dose 1. Another study published in 2003 found that the response to combined hepatitis A and B vaccine decreased with increasing age, and that a booster dose was effective in inducing protective antibodies in elderly individuals 2.
However, it's worth noting that the most recent and highest quality study on this topic is not available, and the current evidence is based on older studies. Nevertheless, based on the available evidence, it is recommended to screen elderly travelers to areas endemic for hepatitis A for the presence of naturally acquired immunity, and if found susceptible, immunize them well in advance of their trip, to allow time for post-vaccination antibody testing and/or administration of a second dose of the vaccine 1.
In terms of the specific vaccine formulation, there is no clear evidence to recommend one formulation over another for elderly individuals, and the choice of vaccine should be based on individual patient factors and preferences. However, higher-dose formulations may be more effective in inducing protective antibodies in elderly individuals with decreased immune response.
Overall, the key takeaway is that hepatitis A vaccine boosters may be necessary for elderly individuals who have completed the initial vaccination series and are planning to travel to areas endemic for hepatitis A, and that a booster dose can provide optimal protection against hepatitis A infection.