Need Help,

I have an '85 Vanagon and the lifters occasionally stick at start-up.
 Typically they will free up before you get out of the driveway.  Today,
however, one stuck and did not free up for several miles.

I have two questions.  First, can this damage my engine?  And second, is
there anything I can do to prevent them from sticking?  

Thanx,

John M.
'85 Vanagon
'65 Ghia Coupe