I have never known of any teachers that have had vacation during the term, all the way from when I was in Kindergarten to graduating from medical school, with HS, undergrad and graduate school in between. I have had several miss a day or so because they were sick, and, sometimes, they take part of a day off for personal business, like closing on a new house.
If it is any consolation to you, working parents of school aged children have the same constraints on their vacation times that teachers do. The difference is that since our business doesn't close down when school is on Christmas, fall, spring or summer break, or on the legal holidays and school improvement days, or snow days, I have to "burn" my vacation days to care for my school aged son. In terms of practicality, I do it because I have a total of 23 PTO days, along with 5 days CME that I can use, while my husband has only 15. Believe it or not, those fall, spring, Christmas, school improvement days, snow days and legal holidays really add up, the same way an extra cookie a day will add 10 pounds over a years time. Since my son has been in school, and not hospital day care, which never closed for holidays or breaks, except the week after Christmas, I have managed to use my total allocation of PTO each year, with only a one week vacation and a 5 day CME trip to show for it. The rest was just nibbled away by various times school was closed and the office was open.
I personally wish that schools were open year round with staggered break times. I guess that would be difficult for other parents, or at least would require a shift in thought process. Actually, it might work better than it would seem on first impression. Then, the various activities that parents use to care for children could be open year round, instead of just a few weeks during the school year and during the summer. So, people who work there would have a steady pay check, and fewer would be needed, since, perhaps, only 1/3 or 1/4 or whatever fraction of kids would be out at any given time. It would completely eliminate the problem we have in our office, namely, we all have kids, and all need the same days off. So, I don't always get to stay home with my son, sometimes my husband does, because we can't have all the doctors gone at the same time. It usually takes alot of cooperation, negotiation and luck for us to be able to take a vacation, all three of us together, at the same time.