I am not sure whether this is a serious typos in a published article Just now i found few short form typos in my published articles few years ago.The mistakes is almost like this: If I declare my first sentences Quantum Chromodynamics (QCD) is one of the most important topics in high energy physics, but i state in same paragraph in second sentences and i type the short form QDC (wrongly) is a is the theory of the strong interaction between quarks and gluons......, i wonder is it consider serious typo? Thank you.
If readers or the editor have not complained to you - they probably smiled to themselves and continued reading - likely thinking "ha, done that typo myself"... 

So, unless you have been contacted don't worry.