Given all that is written in the last post on puppy socialisation, it is very important that your puppy is out and about at the earliest age possible so as to maximise the benefit of the socialisation period. Currently, the earliest you can safely walk your puppy in the UK is somewhere between 10 and 11 weeks old. The most common practice for vaccinating puppies is as follows. The first vaccination is given no later than 8 weeks old. The second vaccination is then given two weeks later at 10 weeks old. Vets usually to tell you to wait roughly 7 days after the second jab before it's safe to walk your pup. This means the day that your puppy turns 11 weeks old and the week that follows is one of the most important weeks in your dogs life, as this is the optimum window for socialisation. You can continue to socialise your pup all through puppyhood, however after the age of 16 weeks he will not be so accepting to new experiences.
This information is intended as a rough guide only. Please check the information with your vet as timings can vary depending on vaccination brand.