I normally give my puppies their first shot when they are between 7 and 8 weeks old. I have this situation come up where I kept one puppy for a family so they could go on a vacation. I'm afraid that by the time they come get their puppy after their vacation, they may forget to take it in 7 days later which would be 3 weeks from the first shot I gave him when he was 7 weeks old.

Is it ok to give this puppy his vaccination 2 weeks after his first vaccination this one time then they can get him on his regular every 3 weeks schedule ?

Didn't vets used to give vaccinations every 2 weeks years ago ?

I would not give pups a booster 2 weeks apart. Perhaps you can suggest to your client to schedule the vet appointment prior to picking up the puppy and bring you the date?

3 to 4 weeks apart

I give / recommend a series of 3 shots. They are given at 8 weeks, 12 weeks and 16 weeks. That seems to be the most common schedule.

Depends on the vaccines, but most of the vaccine packaging (the labelled use information) states that a booster vaccine is given 3-4 wks later. Sounds like you have a little extra time when they get back in town.

Not a good idea to give the vaccinations too close together, it can supress the immune system and cause all kinds of other unwanted problems to crop up... the shots should be spaced 4 weeks apart not 3.
Aloha,
Jackie