As far as I know the strains used each year are determined by the World Health Organisation and so the same vaccines are used worldwide. There are two types of flu vaccine available in Greece at the moment. The first aims to protect against three strains of the virus:
1 A/Michigan/45/2015 (H1N1) pdm09 (The cause of Swine flu in 2009)
2 A/Hon Kong/4801/2014 (H3N2) (Mainly affects the elderly and other high risk groups)
3 B/Brisbane/60/2008 (Mainly affects children)
The other vaccine aims to protect against the same three strains plus a fourth:
All are described as "like virus", i.e. they are similar to the strains listed above. I understand that one of them is a mutated variant of the original strain but I am not sure which one, possibly the first one. The first version of the vaccine appears to be the same as the version being used by the NHS in the UK. Possibly the second version is also available in the UK but perhaps not through the NHS? My pharmacy currently stocks both types.