Respiratory infection, can they catch it again?

[BabyPea]

Hi. I was wondering once a young pea gets a respiratory infection and its healed can it get it again? Do they get immune to it? The reason I ask 3 yrs ago one of my birds got sick and got healed. Never got sick again.
It's just a random thought of mine and was just wondering that.

 

[Midnightman14]

They can get it more than once.

 

[KsKingBee]

It can be a secondary infection or it can be caused by living conditions like dusty coops.

 

[BabyPea]

Thank you for the response.