Anaphylaxis after vaccination appeared rare, according to results of a data analysis.

ResearchersĀ used data from the Vaccine Safety Datalink to identify individuals (median age, 17 years; range, 4-65) who underwent vaccination between January 2009 and December 2011.

They identified 33 cases of anaphylaxis triggered by vaccines after more than 25.1 million vaccine-administered doses. They calculated an anaphylaxis rate of 1.31 (95% CI, 0.9-1.84) per 1 million vaccine doses.

Researchers identified 10 cases of anaphylaxis after receipt of the influenza vaccine, equating to a rate of 1.35 (95% CI, 0.65-2.47) per 1 million doses, and two cases of anaphylaxis after receipt of the inactive monovalent influenza vaccine, equating to a rate of 1.83 (95% CI, 0.22-6.63) per 1 million doses.