TY - JOUR
T1 - The incidence of narcolepsy in Europe
T2 - Before, during, and after the influenza A(H1N1)pdm09 pandemic and vaccination campaigns
AU - Wijnans, Leonoor
AU - Lecomte, Coralie
AU - de Vries, Corinne
AU - Weibel, Daniel
AU - Sammon, Cormac
AU - Hviid, Anders
AU - Svanström, Henrik
AU - Mølgaard-Nielsen, Ditte
AU - Heijbel, Harald
AU - Dahlström, Lisen Arnheim
AU - Hallgren, Jonas
AU - Sparen, Par
AU - Jennum, Poul
AU - Mosseveld, Mees
AU - Schuemie, Martijn
AU - van der Maas, Nicoline
AU - Partinen, Markku
AU - Romio, Silvana
AU - Trotta, Francesco
AU - Santuccio, Carmela
AU - Menna, Angelo
AU - Plazzi, Giuseppe
AU - Moghadam, Keivan Kaveh
AU - Ferro, Salvatore
AU - Lammers, Gert Jan
AU - Overeem, Sebastiaan
AU - Johansen, Kari
AU - Kramarz, Piotr
AU - Bonhoeffer, Jan
AU - Sturkenboom, Miriam C.J.M.
PY - 2013/2/6
Y1 - 2013/2/6
N2 - Background: In August 2010 reports of a possible association between exposure to AS03 adjuvanted pandemic A(H1N1)pdm09 vaccine and occurrence of narcolepsy in children and adolescents emerged in Sweden and Finland. In response to this signal, the background rates of narcolepsy in Europe were assessed to rapidly provide information for signal verification. Methods: We used a dynamic retrospective cohort study to assess the narcolepsy diagnosis rates during the period 2000-2010 using large linked automated health care databases in six countries: Denmark, Finland, Italy, the Netherlands, Sweden and the United Kingdom. Results: Overall, 2608 narcolepsy cases were identified in almost 280 million person years (PY) of follow up. The pooled incidence rate was 0.93 (95% CI: 0. 90-0.97) per 100,000 PY. There were peaks between 15 and 30 year of age (women > men) and around 60 years of age. In the age group 5-19 years olds rates were increased after the start of pandemic vaccination compared to the period before the start of campaigns, with rate ratios (RR) of 1.9 (95% CI: 1.1-3.1) in Denmark, 6.4 (95% CI: 4.2-9.7) in Finland and 7.5 (95% CI: 5.2-10.7) in Sweden. Cases verification in the Netherlands had a significant effect on the pattern of incidence over time. Conclusions: The results of this incidence study provided useful information for signal verification on a population level. The safety signal of increased narcolepsy diagnoses following the start of the pandemic vaccination campaign as observed in Sweden and Finland could be observed with this approach. An increase in narcolepsy diagnoses was not observed in other countries, where vaccination coverage was low in the affected age group, or did not follow influenza A(H1N1)pdm09 vaccination. Patient level analyses in these countries are being conducted to verify the signal in more detail.
AB - Background: In August 2010 reports of a possible association between exposure to AS03 adjuvanted pandemic A(H1N1)pdm09 vaccine and occurrence of narcolepsy in children and adolescents emerged in Sweden and Finland. In response to this signal, the background rates of narcolepsy in Europe were assessed to rapidly provide information for signal verification. Methods: We used a dynamic retrospective cohort study to assess the narcolepsy diagnosis rates during the period 2000-2010 using large linked automated health care databases in six countries: Denmark, Finland, Italy, the Netherlands, Sweden and the United Kingdom. Results: Overall, 2608 narcolepsy cases were identified in almost 280 million person years (PY) of follow up. The pooled incidence rate was 0.93 (95% CI: 0. 90-0.97) per 100,000 PY. There were peaks between 15 and 30 year of age (women > men) and around 60 years of age. In the age group 5-19 years olds rates were increased after the start of pandemic vaccination compared to the period before the start of campaigns, with rate ratios (RR) of 1.9 (95% CI: 1.1-3.1) in Denmark, 6.4 (95% CI: 4.2-9.7) in Finland and 7.5 (95% CI: 5.2-10.7) in Sweden. Cases verification in the Netherlands had a significant effect on the pattern of incidence over time. Conclusions: The results of this incidence study provided useful information for signal verification on a population level. The safety signal of increased narcolepsy diagnoses following the start of the pandemic vaccination campaign as observed in Sweden and Finland could be observed with this approach. An increase in narcolepsy diagnoses was not observed in other countries, where vaccination coverage was low in the affected age group, or did not follow influenza A(H1N1)pdm09 vaccination. Patient level analyses in these countries are being conducted to verify the signal in more detail.
KW - ASO3B adjuvant
KW - Background rates
KW - Incidence
KW - Influenza vaccine
KW - Narcolepsy
UR - http://www.scopus.com/inward/record.url?scp=84873082021&partnerID=8YFLogxK
U2 - 10.1016/j.vaccine.2012.12.015
DO - 10.1016/j.vaccine.2012.12.015
M3 - Article
C2 - 23246544
AN - SCOPUS:84873082021
SN - 0264-410X
VL - 31
SP - 1246
EP - 1254
JO - Vaccine
JF - Vaccine
IS - 8
ER -