FDA Approves Extended Use of Tdap Vaccine

The U.S. Food and Drug Administration has approved the use Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine Adsorbed (Tdap) to include repeat vaccination to help protect against tetanus, diphtheria and pertussis. The vaccine is produced by Sanofi under the market name Adacel.

The approval was granted based on data from a study assessing the efficacy of the vaccine in a population of more than 1300 adults. Participants received either the Adacel vaccine or a tetanus-diptheria vaccine during a period 8-12 years following a dose of the Adacel vaccine. Results indicated that the second dose of Adacel vaccine in adults administered 8-12 years after a previous dose found no significant differences in reported adverse events between the 2 vaccine groups. In total 999 participants in the Tdap vaccine group (87.7%) and 328 participants in the Td vaccine group (88%) reported at least 1 injection-site reaction.

The approval has made the vaccine the first and only Tdap vaccine in the US approved for a repeat dose in individuals between the ages of 10 through 64 years, following 8 years or more after the first vaccination. The vaccine is also unique in that it is the only Tdap vaccine available in a syringe made without rubber latex, which may reduce the risk of the vaccine to individuals with allergies to latex.

"While strong vaccination programs are in place for young adolescents, a single Tdap immunization does not offer lifetime protection against pertussis due to waning immunity," David P. Greenberg, MD, Regional Medical Head North America at Sanofi Pasteur, said in a statement. "The licensure of Adacel as the first Tdap vaccine in the U.S. for repeat vaccination is an important step for eligible patients and offers flexibility for health care providers to help manage their immunization schedules."

Current recommendations of the US Centers for Disease Control and Prevention (CDC) include a single dose of Tdap vaccine for adolescents and adults, and for pregnant women a vaccination during every pregnancy. Tdap helps protect adolescents and adults and may prevent the spread of the infection to babies and young children who are still building immunity. Despite the CDC-recommendation, approximately 75% of adults have not received the Tdap vaccine.

Sanofi Pasteur has provided the results of the study to the CDC's Advisory Committee on Immunization Practices for their consideration in future recommendations.