Get vaccinated. If you're adults you can get a combo Hep A/Hep B injection. I think it's a series of three injections, spread over a year or so. You will have some protection after the first dose. But, get it soon, takes a couple of weeks to be effective.
The combo hep A/B vaccine is called "Twinrix" and is given in a series of 3 injections: an initial dose followed by doses at 1 month and 6 months.
While it true that just one injection does provide soem immunity, it is quite a bit lower than that achieved by two injections, which again is less than the full series.
If only one dose can be given due to time cojiderations, an individual hep A vaccine instead of one shot of the combination vaccine may provide better protection against A.
Following the final dose, immunity to the hepatitis B virus is thought to be lifelong; hep A vaccine probably should be repeated after an interval of 10-yrs or so. Neither provides 100% protection, but the immunity conferred is quite high.
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.