CORRECTED - Glaxo may not launch Synflorix vaccine in U.S.

(Corrects in second paragraph that drug was recommended for approval (not approved).

LONDON Feb 5 (Reuters) - GlaxoSmithKline Plc (GSK.L) may not launch its new pneumococcal vaccine Synflorix in the United States, opting for a different product instead, its chief executive said on Thursday.

Synflorix, which was recommended for approval in Europe last month, will compete with Wyeth's WYE.N blockbuster Prevnar, the world's top-selling vaccine, which had sales of $2.4 billion in 2007. Glaxo has not submitted it for approval in the United States.

"It's clear that Synflorix versus Prevnar is a much more competitive innovation outside of the U.S. because of the presence of different pneumococcal subtypes," Andrew Witty told analysts after reporting 2008 results.

"We haven't finally decided, but I think we are more likely to tackle the U.S. with a different type of vaccine to Synflorix. My expectation, subject to some further analysis, is it probably won't be Synflorix we take to the U.S.," he added.

Glaxo's new vaccine is designed to offer protection against both invasive pneumococcal disease and bacterial respiratory infections.

It is active against 10 types of streptococcus pneumoniae, compared with seven strains for Prevnar.

Wyeth -- which agreed last week to be acquired by Pfizer Inc (PFE.N) -- also has an improved version of Prevnar, active against 13 strains, which was submitted for approval in Europe in December.

Pneumococcal disease covers a number of illnesses caused by the bacterium Streptococcus pneumoniae, including meningitis, sepsis, pneumonia and otitis media. (Reporting by Ben Hirschler; Editing by David Holmes and Carol Bishopric)