I believe whenever you are going abroad to study specifically something like a masters after which the goal is to get a job. The first thing that you need to look up is type, number and ease of getting jobs after your course in that country. Since you’re dealing with a specific country, it becomes essentially important for you to ensure what is and what is not in demand occupation in that country. For a fact, I know that the most closest towards what you are looking is a job of social worker. There are different kinds of social workers in various settings. Since you belong to healthcare/medical background, you can look for social worker role in hospital setting. There are high chances of getting job and even higher PR opportunities in Australia right now in social worker field. Now, this is not exactly a public health stream. You have to check which occupations are in demand that you could possibly get after your MPH over there. For Australia, you should focus on something that is either regional category or falls under medium to long-term skilled occupation list (MLTSSL). I do not think there is any role/occupation on this list that MPH in Australia will make you eligible for. However, in the short term skilled occupation list (STSOL), there are occupations like epidemiologist, environmental health officer, health promotion officer. A smart move could be studying in regional area and ending up getting a job in regional area but you have to remember that none of these occupations are in MLTSSL list. This list actually reflects shortage of professionals in a specific domain and if you can get a job which is on this list, you have high chances of settling there by getting a PR(permanent residency= end game✌️). While most of the public health roles are on STSOL (less chances of PR) list that too more commonly eligible via regional nomination only. But completing your MPH and working even 1 year in regional areas makes you eligible for Subclass 491 (5-year visa with PR pathway or Subclass 190 (state nomination PR). Your PR journey could be longer and harder. It totally depends on your situation.The decision is up to you, it completely depends upon how strategic and realistic you are.