tetano
Editor, Senior Moderator
Vaccine
Available online 19 October 2013
Increased risk of anaphylaxis following administration of 2009 AS03-adjuvanted monovalent pandemic A/H1N1 (H1N1pdm09) vaccine
Isabelle Rouleaua,
Gaston De Serresa, b, Corresponding author contact information, E-mail the corresponding author,
Jean Philippe Droleta,
Danuta Skowronskic,
Manale Ouakkib,
Eveline Tothd,
Monique Landryd,
Suzanne M?narde,
R?mi Gagnona
a Centre hospitalier universitaire de Qu?bec, Quebec City, Quebec, Canada
b Institut national de sant? publique du Qu?bec, Quebec, Canada
c British Columbia Centre for Disease Control, Vancouver, Canada
d Minist?re de la sant? et des services sociaux du Qu?bec, Montr?al, Qu?bec, Canada
e Agence de sant? et de services sociaux de l?Estrie, Sherbrooke, Qu?bec, Canada
Highlights
?
Quebec passive surveillance showed an increase in anaphylaxis after H1N1pdm09 vaccination.
?
Many cases which were reported as other AEFI also met the criteria for anaphylaxis.
?
Anaphylaxis was likely underrecognized and its incidence higher than passively observed.
?
Incidence of anaphylaxis is estimated at 13 per million doses administered.
?
Enhanced public awareness is unlikely to be the predominant explanation for this increase.
Abstract
Background
Anaphylaxis after trivalent influenza vaccination is typically reported at a rate of <1 per million doses. In Quebec, Canada, anaphylaxis following administration of the monovalent AS03-adjuvanted H1N1pdm09 vaccine was reported through passive surveillance at a rate of 8 per million doses administered. This was 20 times higher than the reporting rate for non-adjuvanted trivalent vaccines administered during the six previous seasons. However, adequate estimation of the incidence of anaphylaxis is hindered by wide variations in definitions and diagnosis.
Methods
Using the Brighton collaboration case definition of anaphylaxis, all cases with allergic symptoms (AS) reported to public health were reviewed to estimate the incidence of anaphylaxis following AS03-adjuvanted H1N1pdm09 vaccine.
Results
Among 752 reports of allergic symptoms, 33 were initially reported as anaphylaxis of which 20/33 (60%) met the Brighton definition (19/20 with certainty levels 1 or 2). A total of 38 additional cases with onset within 1 h of vaccination also met the Brighton definition of anaphylaxis (27 (71%) with certainty levels 1 or 2). The 58 cases meeting Brighton Level 1 or 2 criteria for anaphylaxis represent a 75% increase over the 33 passively reported and an incidence of 13 per million doses administered.
Conclusion
A substantial number of patients with early-onset allergic symptoms met the most specific levels of the Brighton case definition but were not reported as anaphylaxis. Based on this specific case definition, the incidence of anaphylaxis after AS03-adjuvanted H1N1pdm09 vaccine substantially exceeded that reported with seasonal influenza vaccines, a signal that warrants better understanding.
http://www.sciencedirect.com/science/article/pii/S0264410X13014096
Available online 19 October 2013
Increased risk of anaphylaxis following administration of 2009 AS03-adjuvanted monovalent pandemic A/H1N1 (H1N1pdm09) vaccine
Isabelle Rouleaua,
Gaston De Serresa, b, Corresponding author contact information, E-mail the corresponding author,
Jean Philippe Droleta,
Danuta Skowronskic,
Manale Ouakkib,
Eveline Tothd,
Monique Landryd,
Suzanne M?narde,
R?mi Gagnona
a Centre hospitalier universitaire de Qu?bec, Quebec City, Quebec, Canada
b Institut national de sant? publique du Qu?bec, Quebec, Canada
c British Columbia Centre for Disease Control, Vancouver, Canada
d Minist?re de la sant? et des services sociaux du Qu?bec, Montr?al, Qu?bec, Canada
e Agence de sant? et de services sociaux de l?Estrie, Sherbrooke, Qu?bec, Canada
Highlights
?
Quebec passive surveillance showed an increase in anaphylaxis after H1N1pdm09 vaccination.
?
Many cases which were reported as other AEFI also met the criteria for anaphylaxis.
?
Anaphylaxis was likely underrecognized and its incidence higher than passively observed.
?
Incidence of anaphylaxis is estimated at 13 per million doses administered.
?
Enhanced public awareness is unlikely to be the predominant explanation for this increase.
Abstract
Background
Anaphylaxis after trivalent influenza vaccination is typically reported at a rate of <1 per million doses. In Quebec, Canada, anaphylaxis following administration of the monovalent AS03-adjuvanted H1N1pdm09 vaccine was reported through passive surveillance at a rate of 8 per million doses administered. This was 20 times higher than the reporting rate for non-adjuvanted trivalent vaccines administered during the six previous seasons. However, adequate estimation of the incidence of anaphylaxis is hindered by wide variations in definitions and diagnosis.
Methods
Using the Brighton collaboration case definition of anaphylaxis, all cases with allergic symptoms (AS) reported to public health were reviewed to estimate the incidence of anaphylaxis following AS03-adjuvanted H1N1pdm09 vaccine.
Results
Among 752 reports of allergic symptoms, 33 were initially reported as anaphylaxis of which 20/33 (60%) met the Brighton definition (19/20 with certainty levels 1 or 2). A total of 38 additional cases with onset within 1 h of vaccination also met the Brighton definition of anaphylaxis (27 (71%) with certainty levels 1 or 2). The 58 cases meeting Brighton Level 1 or 2 criteria for anaphylaxis represent a 75% increase over the 33 passively reported and an incidence of 13 per million doses administered.
Conclusion
A substantial number of patients with early-onset allergic symptoms met the most specific levels of the Brighton case definition but were not reported as anaphylaxis. Based on this specific case definition, the incidence of anaphylaxis after AS03-adjuvanted H1N1pdm09 vaccine substantially exceeded that reported with seasonal influenza vaccines, a signal that warrants better understanding.
http://www.sciencedirect.com/science/article/pii/S0264410X13014096