The quick answer to, “Can you play Pandemic Legacy more than once?” is yes but there is a finite number of times.
There is a storyline that follows 12 months. Once you have played through that storyline and have either won or lost then you cannot replay the story. You will be able to play between 12 and 24 games.
Pandemic Legacy is a fantastic genre of games that are very popular. As of publishing this article Pandemic Legacy is sitting at number 2 of the Board Game Geek charts. This has got to be one of the games you should check out.