Big Pharma continues to expand into the vaccine market as Pfizer purchased privately owned PowderMed this week, hoping for an ouch-free entry into this segment. The vaccine market is suddenly looking golden to Big Pharma when just a few years ago it seemed that most drugmakers wouldn’t go near vaccines.

Now with government encouragement and the promise of fairly predictable growth, Big Pharma is into vaccines in a big way. With U.K.-based PowerMed, Pfizer is getting a company developing needle-free, DNA-based vaccines.

PowderMed’s technology shoots— at supersonic speed—DNA-coated gold particles into the skin. Using DNA-based vaccines could help replace old-style vaccines cultured in chicken eggs, for example. Manufacturing costs are one of the biggest roadblocks to vaccine profitability.

PowderMed is currently testing its technology in six trials for influenza and other viral diseases.

Pfizer isn’t the only Big Pharma company injecting itself into vaccine markets. In 2005, Novartis bought California-based biotech Chiron for $5.1 billion and GlaxoSmithKline plans to launch at least four new vaccines in the next five years. Glaxo also recently acquired ID Biomedical of Canada.