My boyfriend has chronic HBV infection. When I knew him, his DNA load was around something *10^5. I had blood tests twice last year, HBsAg negative and HBsAb positive. This year, when I lodged my permanent visa in Australia, I was tested for HBsAg again, and it was negative. So I would say that, in my case, vaccination is the best protection. By the way, my boyfriend is a nice guy, and I believe HBV should not be the obstacle for us.
Regarding Australian visa, if it is for permanent residency (PR), policies say that the applicants need to take HIV and HBsAg tests, but it doesn’t mean testing HBsAg positive will be a problem. For other types of visa, such as student visa (subclass 500), HBsAg test is not compulsory.
If you want to lodge PR visa, HBsAg test is required. However, for most occupations, if the DNA load is lower than 2000 it is alright. If you are on medication, then the costs for 10 years should not exceed 81,000 Australian dollars. The amount has been updated this year. Before the update, it was 60k something. So, whether it is Entecavir or TDF, the costs are within 81,000 and it shall be all good.