Sudden unexpected deaths and vaccinations during the first two years of life in Italy: A case series study

Giuseppe Traversa, Stefania Spila-Alegiani, Clara Bianchi, Marta Ciofi Degli Atti, Luisa Frova, Marco Massari, Roberto Raschetti, Stefania Salmaso, Gianpaolo Scalia Tomba

Research output: Contribution to journalArticle

Abstract

Background: The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings: The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999-2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1-23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0-1, 0-7, and 0-14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0-7 and 0-14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions: The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age.

Original languageEnglish
Article numbere16363
JournalPLoS One
Volume6
Issue number1
DOIs
Publication statusPublished - 2011

Fingerprint

Immunization
Sudden Death
Italy
Vaccination
Vaccines
vaccination
death
vaccines
immunization
Germany
Death Certificates
dosage
Registries
History
Population
history

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Traversa, G., Spila-Alegiani, S., Bianchi, C., Atti, M. C. D., Frova, L., Massari, M., ... Tomba, G. S. (2011). Sudden unexpected deaths and vaccinations during the first two years of life in Italy: A case series study. PLoS One, 6(1), [e16363]. https://doi.org/10.1371/journal.pone.0016363

Sudden unexpected deaths and vaccinations during the first two years of life in Italy : A case series study. / Traversa, Giuseppe; Spila-Alegiani, Stefania; Bianchi, Clara; Atti, Marta Ciofi Degli; Frova, Luisa; Massari, Marco; Raschetti, Roberto; Salmaso, Stefania; Tomba, Gianpaolo Scalia.

In: PLoS One, Vol. 6, No. 1, e16363, 2011.

Research output: Contribution to journalArticle

Traversa, G, Spila-Alegiani, S, Bianchi, C, Atti, MCD, Frova, L, Massari, M, Raschetti, R, Salmaso, S & Tomba, GS 2011, 'Sudden unexpected deaths and vaccinations during the first two years of life in Italy: A case series study', PLoS One, vol. 6, no. 1, e16363. https://doi.org/10.1371/journal.pone.0016363
Traversa, Giuseppe ; Spila-Alegiani, Stefania ; Bianchi, Clara ; Atti, Marta Ciofi Degli ; Frova, Luisa ; Massari, Marco ; Raschetti, Roberto ; Salmaso, Stefania ; Tomba, Gianpaolo Scalia. / Sudden unexpected deaths and vaccinations during the first two years of life in Italy : A case series study. In: PLoS One. 2011 ; Vol. 6, No. 1.
@article{da9096030e41453d8fa97041abfcf22e,
title = "Sudden unexpected deaths and vaccinations during the first two years of life in Italy: A case series study",
abstract = "Background: The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings: The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999-2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1-23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0-1, 0-7, and 0-14 days after immunisation. Among the 604 infants who died of SUD, 244 (40{\%}) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95{\%} CI 0.6 to 4.2). The RRs for the risk periods 0-7 and 0-14 were 2.0 (95{\%} CI 1.2 to 3.5) and 1.5 (95{\%} CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95{\%} CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions: The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age.",
author = "Giuseppe Traversa and Stefania Spila-Alegiani and Clara Bianchi and Atti, {Marta Ciofi Degli} and Luisa Frova and Marco Massari and Roberto Raschetti and Stefania Salmaso and Tomba, {Gianpaolo Scalia}",
year = "2011",
doi = "10.1371/journal.pone.0016363",
language = "English",
volume = "6",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "1",

}

TY - JOUR

T1 - Sudden unexpected deaths and vaccinations during the first two years of life in Italy

T2 - A case series study

AU - Traversa, Giuseppe

AU - Spila-Alegiani, Stefania

AU - Bianchi, Clara

AU - Atti, Marta Ciofi Degli

AU - Frova, Luisa

AU - Massari, Marco

AU - Raschetti, Roberto

AU - Salmaso, Stefania

AU - Tomba, Gianpaolo Scalia

PY - 2011

Y1 - 2011

N2 - Background: The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings: The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999-2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1-23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0-1, 0-7, and 0-14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0-7 and 0-14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions: The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age.

AB - Background: The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings: The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999-2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1-23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0-1, 0-7, and 0-14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0-7 and 0-14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions: The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age.

UR - http://www.scopus.com/inward/record.url?scp=79551526442&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79551526442&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0016363

DO - 10.1371/journal.pone.0016363

M3 - Article

C2 - 21298113

AN - SCOPUS:79551526442

VL - 6

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 1

M1 - e16363

ER -