Questionable. The two vaccinations for Hep A are supposed to be given within 6-12 months of each other for the highest efficacy. A single vaccination covers 10 years, while having both provides immunity for at least 20 years. Given the multi-year spacing between vaccines, I'm not sure which category you fall into. If you are at risk for Hep A, you can always get the two-dose series again - it won't hurt anything.