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TOKEN Study on deaths in young children (2nd to 24th month of life) finalised

Blick auf eine Steinbrücke über ein Gewässer. Quelle: © RKI Source: © Robert Koch-Institut

The TOKEN study was performed by the RKI between July 2005 and July 2008. Two hundred fifty-four unexplained sudden unexpected deaths (uSUD) were studied to assess a possible relationship between hexavalent vaccination and uSUD of children.

The main study analyses showed no increased risk of sudden death within one week after hexavalent vaccination.

Detailed information about cases, including their vaccination history, parent and physician questionnaires and autopsy reports, were collated and scientifically assessed. Temporal association of uSUD to vaccination was examined in a self-controlled case series (SCCS) design. These results were additionally validated in a case-control design. In a separate pathological study part, standardised post mortem examinations were conducted to identify any common pathological mechanism for sudden death after vaccinations.

  • The main study analysis plus the additional analyses showed no increased risk of sudden death within one week after hexavalent vaccination
  • The case-control analysis was in accordance with this finding and did not suggest a risk increase within one week after hexavalent vaccination.
  • In the SCCS analysis, the risk of uSUD was not statistically significantly increased during the first three days after hexavalent vaccination.
  • A risk reduction was shown between days four and seven after vaccination.
  • The case-control analysis was in accordance with these observations and did not suggest a risk increase within the first three days after vaccination.
  • Results of the investigations performed in the pathological study part did not indicate towards a common pattern among vaccinated cases.
  • Almost all young children who died in close temporal relationship to vaccination had recognised risk factors for sudden infant death syndrome (SIDS): prone sleeping, maternal smoking or risk for hyperthermia due to heavy wrapping or clothing, or overheating. Prone sleeping and other risk factors should be strictly avoided during the whole first year of life

Unfortunately, the response proportion of parents was a low 40% despite all attempts towards better study participation. Parents whose child had died shortly after a vaccination were more likely to participate than parents whose child had died in more remote temporal relationship to a vaccination or who had not been vaccinated at all. This introduced an important bias into the TOKEN study and impedes interpretation of the study results. However, for methodological reasons it can be assumed that the results of this study most likely overestimate the true risk.

For this study, the RKI was supported by Local Health Authorities, forensic institutes and paediatricians throughout Germany. The study was supported and sponsored by the Paul-Ehrlich-Institute (PEI) and the Federal Ministry of Health (Bundesministerium für Gesundheit). In addition, study sponsoring was provided by the pharmaceutical companies, GlaxoSmithKline Biologicals and Sanofi-Pasteur MSD. The study was developed and conducted in close cooperation with an international, interdisciplinary Scientific Advisory Board.

A German and an English summary are included in the report.

Date: 08.03.2011