Certain vaccine varieties are excelling over others in the senior population, tipping off providers ahead of the main flu season.

Cell-based vaccines have performed better than egg-based vaccines among Medicare beneficiaries. That’s according to U.S. Food and Drug Administration researchers, who conducted an analysis of more than 13 million seniors who received one of five formulations.

“The lessons we learn from these studies will help improve influenza vaccines and vaccine strategies so that we optimize the protection provided by seasonal influenza vaccines,” epidemiologists from the CDC wrote in an accompanying editorial.

The formulations included Flucevax, egg-based quadrivalent, egg-based high-dose, adjuvanted and standard-dose vaccines. Flu-related emergency room visits were studied. The analysis — done in conjunction with the Centers for Medicare & Medicaid Services — noted that cell-cultured vaccines’ effectiveness was upward of 11% higher than the standard-dose, egg-based version.

Results were published this week in the Journal of Infectious Diseases.