Yes, multiple applicants can be hired for the same posted job. To continue accepting applicants after initiating a hire, simply opt to keep the job posted. If you'd like to stop the flow of new applicants, you can pause the job, which removes it from job boards, but lets you continue to process and hire or reject the remaining applicants in your queue.
Tip: The Summary in the upper right corner of the job displays details of the job, including how many applicants have been hired.