UPDATE 1-Sanofi "micro" flu shot wins European approval

* First of a new kind of vaccine against seasonal flu

* Developed in collaboration with Becton Dickinson

* Joint venture with Merck to market shot in W.Europe

(Adds details, background)

PARIS, Feb 26 (Reuters) - A new kind of "micro" vaccine against seasonal flu from Sanofi-Aventis (SASY.PA) has been cleared for sale by the European Commission, the French drugmaker said on Thursday.

The green light had been expected following a positive recommendation from the European Medicines Agency in December.

Sanofi's Intanza vaccine is the first intradermal microinjection flu shot and was developed in collaboration with Becton Dickinson (BDX.N), a specialist in injection technology.

Intradermal vaccination involves administering antigen into the dermal layer of the skin, which has a high concentration of specialised immune cells.

The shot is approved for use in adults 60 years of age and older, especially in those who run an increased risk of influenza-associated complications.

Older people tend to become less responsive to vaccination, a phenomenon known as immunosenescence, and are expected to benefit particularly from a vaccine that provides direct access to the immune system through the dermal skin layer.

Sanofi, the world's biggest supplier of flu vaccines, has tested the new shot in clinical trials involving more than 7,000 adult or elderly participants.

Intanza will be marketed in Western Europe by Sanofi Pasteur MSD -- a 50/50 joint venture between Sanofi and Merck & Co (MRK.N). Elsewhere, it will be sold by Sanofi's vaccine division, Sanofi Pasteur. (Reporting by Ben Hirschler; Editing by Mike Nesbit)