Final answer:
IgG-HAVAb is the antibody indicative of long-term immunity to Hepatitis A virus, providing protection against reinfection.
Step-by-step explanation:
The antibody that is protective against reinfection with hepatitis A virus (HAV) is IgG-HAVAb. This antibody indicates long-term immunity and protection against HAV. Producing IgG antibodies against the virus usually follows the acute phase of hepatitis A, characterized by the presence of IgM-HAVAb, which indicates recent infection. Once a person has recovered from HAV, they typically have lifelong immunity due to the protective IgG antibodies that remain in their system.