* EU agency backs vaccines from Glaxo, Novartis
* Clears way for mass vaccinations to start imminently
* Two-dose schedule recommended but this may be updated
* Baxter expects its shot to win recommendation "in days"
* Glaxo shares up 1.7 pct, Baxter up 1.2 pct, Novartis flat
(Adds analyst comment, latest share prices)
By Ben Hirschler and Kate Kelland
LONDON, Sept 25 (Reuters) - European healthcare regulators recommended two swine flu vaccines for approval on Friday, clearing the way for mass vaccination programmes to start imminently.
Governments and manufacturers have been scrambling for vaccines to target the new H1N1 flu strain, ahead of a feared second wave of infection as the northern hemisphere heads into winter.
The European Medicines Agency (EMEA) said its expert committee on new drugs gave the go-ahead for the first H1N1 swine flu vaccines from GlaxoSmithKline and Novartis, called Pandemrix and Focetria.
The shots now only need final approval from European Commission, a move EMEA chief executive Thomas Lonngren said he expected to happen "very rapidly ... hopefully next week" as part of an accelerated regulation system for pandemic vaccines.
A third vaccine from Baxter, which had also been submitted under the fast-track "mock-up" procedure, did not get a green light, but the watchdog said it was still reviewing this and other applications.
A spokeswoman for Baxter said it expected to receive a positive opinion "within days".
Shares in Glaxo rose 1.7 percent by 1350 GMT, buoyed by the European green light.
"They weren't first out of the gate with the other players in the U.S. -- although they are confident of getting approval there -- so this has given them a bit of boost," said Navid Malik, an industry analyst at Matrix Corporate Capital.
Baxter stock added 1.2 percent, while Novartis was flat.
The World Health Organisation (WHO) said on Thursday that drugmakers will only be able to produce enough H1N1 vaccine each year for half the planet -- around 3 billion doses per year -- meaning governments will have to decide who should get the limited supplies.
The WHO added that a single dose should be enough to give immunity to healthy adults and older children from the virus commonly known as swine flu, which was declared a pandemic in June.
TWO DOSES...FOR NOW
The EMEA, however, said it was currently recommending two doses be given, at an interval of three weeks, although it acknowledged preliminary data suggested one dose might suffice and this recommendation could be updated as new data comes in.
The London-based watchdog said it was confident the new vaccines were safe, despite being rushed through the approval process, adding manufacturers would have to carry out safety studies in 9,000 subjects for each vaccine after launch.
"Decades of experience with seasonal influenza vaccines indicate that insertion of a new strain in a vaccine should not substantially affect the safety or level of protection offered," the agency said in a statement.
Both the Glaxo and Novartis shots contain adjuvants -- substances that enhance the immune response so that less active ingredient, or antigen, can be used in each dose.
Glaxo said its vaccine contained just 3.75 micrograms of antigen while the Novartis product contains 7.5 micrograms. That compares with 15 micrograms needed in non-adjuvanted vaccines.
Most rich nations have contracts with drugmakers to obtain enough vaccine to cover their populations and governments have already been building up stockpiles ahead of the shots winning regulatory approval.
But poorer countries lack the financial resources to compete for an early share of limited supplies.
Earlier this month, America's Food and Drug Administration (FDA) approved H1N1 flu vaccines from four drugmakers -- Sanofi-Aventis, CSL, AstraZeneca's MedImmune unit and Novartis.
The WHO says it will begin an initial distribution of around 300 million doses of H1N1 vaccine donated by rich nations to more than 90 developing countries from November. (Additional reporting by Ben Deighton; Editing by David Cowell)