Sanofi

2. Sanofi
2013 sales: $5.52 billion

Coming in second is Sanofi ($SNY), which held 21.6% of the worldwide vaccines market in 2013, according to EvaluatePharma. Powering that share were two top-10 sellers: Pentacel, which raked in $1.53 billion last year to score the No. 3 spot, and influenza shot Fluzone/Vaxigrip, which followed right behind it in fourth place with $1.4 billion in 2013 sales.

Sanofi also reaps sales of No. 2 seller Gardasil, which is marketed by the French drugmaker's joint venture with Merck ($MRK)--Sanofi Pasteur MSD--in Europe. Those may soon be growing, thanks to a brand-new European Commission indication for preventing anal cancer.

But while Sanofi may be trailing now, it will be in the lead come 2020, EP predicts. It expects to see the pharma giant's vaccines sales climb to $8.81 billion that year, beating out runner-up Merck by more than $600 million.

The company's highly anticipated dengue vaccine may put it over the edge. Analysts expect about $1.4 billion in peak sales for the jab, which, in Phase III, is the closest candidate to market to protect against the deadly, widespread disease.

For more:
Solid PhIII brings Sanofi closer to blockbuster dengue sales
Sanofi, CureVac extend vax partnership with new $205M-plus mRNA pact
Merck, Sanofi JV wins anal cancer indication for Gardasil in EU
Sanofi's Shan5 overcomes manufacturing setback to score thumbs up from WHO