Novartis

5. Novartis
2013 sales: $1.42 billion

Novartis ($NVS) may rank among the world's top 5 vaccine makers now, but come next year, that status will be a thing of the past if all goes as planned. After years of struggling in the shadow of Big 3 rivals Sanofi ($SNY), GlaxoSmithKline ($GSK) and Merck ($MRK), the Swiss pharma agreed in April to ride pharma's slim-down wave, sending most of the division to GSK for $7.1 billion.

With it will go Bexsero, the world's first meningitis B vaccine, which is currently on the market in Europe and awaiting regulatory approval in the U.S. And while Novartis touted Bexsero's potential for years, pinning the foundering unit's hopes on the vaccine, the tradeoff for the Basel-based drugmaker is that Glaxo will also take on most of a division that posted $165 million in 2013 operating losses.

But with its own influenza offerings, GSK won't be taking Novartis' flu vaccines off its hands, and the company has said it's working on a separate sales process to divest that lineup. While it doesn't include a quadrivalent shot--the type that brought sales boosts to competitors that rolled them out for last year's flu season--it does have cell-culture vaccine Flucelvax, along with a newly green-lighted U.S. facility to produce it.

All hasn't been rosy for the flu business, however. It's hit a couple of snags as of late, including a patent infringement lawsuit in Europe from Canada-based Microbix and an Italian probe into possible fraud linked to flu-vaccine pricing.

For more:
Novartis' soon-to-be-Glaxo's vaccine unit sees mounting losses, diving sales in Q2
Italian officials probe Novartis for possible flu vaccine pricing fraud
Novartis submits Bexsero to FDA in race for MenB market
Novartis facility grabs FDA license to produce cell-culture vaccines