The U.S. Food and Drug Administration announced that it has approved Novartis' seasonal influenza vaccine Flucelvax that has been manufactured using animal cells. The vaccine has been approved for use by people over 18 years of age.

This is the first time that the agency has approved a vaccine that's been manufactured using animal cell culture instead of fertilized chicken eggs.

Influenza vaccines have been made using fertilized chicken eggs for over 60 years. The rapid spread of swine flu in 2009 showed that vaccine production requires newer technologies so that more people can be vaccinated in time.

Cell culture technology, as opposed to egg culture, helps quicken the manufacturing process in the events of an emergency, FDA said. Also, using this technology would mean that an adequate amount of vaccine, that has been tested, is always available.

"Today's approval represents the culmination of efforts to develop a seasonal influenza vaccine using cell culture as an alternative to the egg-based process," said Karen Midthun, M.D., director of the FDA's Center for Biologics Evaluation and Research.

Flucelvax was tested on 7,700 people of ages 18 to 49 years. Compared to placebo, flucevax was 83 percent more effective, FDA said.

Side effects of Flucevax included pain, redness and soreness at the injection site, headache and fatigue. Safety trial for the drug was carried out on 6,700 individuals.

Flucelvax is manufactured by Novartis Vaccines and Diagnostics GmbH, Marburg, Germany.

All people above 6 months of age should get the flu shot annually, says Centers for Disease Control and Prevention.