60 Minutes correspondent Scott Pelley is given a tour of the Sanofi Pasteur plant in Swiftwater, PA., - the only one in America making the H1N1 flu vaccine - as the virus is incubated in eggs, a major step in the vaccine-making process.

Sanofi Pasteur Director of Manufacturing and Technology Sam Lee took Pelley through the plant Tuesday where over 30,000 eggs an hour are processed in the effort to produce millions of vaccine doses.

Pelley's report on the manufacture, distribution and safety of the H1N1 vaccine will be broadcast on 60 Minutes  tonight.