Sinovac has stated that it can produce 20-30MM doses by the end of this year and I see no reason not to take Yin's word for it. They appear to have already begun production and should be able to distribute these doses in a timely fashion.
Second, this is not a competition between Chinese companies. This is an "all hands on deck" situation. Whoever can produce in a timely fashion will sell what they produce.
Moreover, Sinovac is quickly developing relationships (with orders almost sure to follow) from several countries: Mexico, Ukraine, Greece, and S. Korea---all four are clearly in play and have been mentioned in recent PRs---and there are several other possibilities from other relationships Sinovac has already formed (e.g. Thailand, Philippines, Russia).
In addition, it seems likely, as the co. has mentioned, that SVA will license (or already has licensed) H1N1 vaccine production to other Chinese companies and earn royalties. But I'll leave this out of the equation for now.
My best guess is that Sinovac will sell 13MM doses in China this season. Even at a super-discounted price per dose of $2.80 (the same price as Sinovac's seasonal flu vaccine), that's $36.4MM. Then it will export 12MM doses at $21 per dose (this figure from an interview Yin gave to a Spanish outlet last weekend and is still 30% below market). That would generate $252MM in revenue, or total H1N1 domestic and export vaccine sales of $288.4MM. I'd guess that half of this will come in 2009 and half in 2010.
Current non-H1N1 vaccine guidance for 2009 revenue from SVA is near 60MM, which is 29% over 2008 (and I expect it to exceed this, based on recent non-H1N1 developments). H1N1 sales this year will bring this figure over $200MM.
Even if there are NO H1N1 vaccine sales for 2010-11 (possible, but not likely), the H1N1 crisis is enabling SVA to generate a ton of cash; it already has $47MM as of June 30. This cash will go into acquisitions, expanded production capacity for Sinovac's other three commercialized vaccines, and R&D for its pipeline of 11-12(!) OTHER products.
All of this should justify a much higher valuation.