Sanofi Pasteur has announced that clinical tests have shown its influenza A (H1N1) vaccine to be effective in adults after just one dose.

Clinical data from the trials indicates that a single 15mcg dose of Sanofi Pasteur’s monovalent vaccine, when administered to adults induced a robust antibody response 21 days post-vaccination.

Sanofi Pasteur president and CEO Wayne Pisano said that consistency of the findings among these separate independent trials will help build public confidence in the vaccine.

“The independent clinical trials conducted by NIH and Sanofi Pasteur provide a rich data set that can be utilised to make informed decisions on vaccine administration,” Pisano said.

Sanofi Pasteur began clinical trials in the US in August to test the vaccine’s efficacy in adults 18 years of age and older, 65 years of age and older, and in children from six months to nine years.

Final data from these clinical trials, following a second dose of vaccine, will provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.