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Randomized Controlled Trial
. 2009 Oct;155(4):495-9.
doi: 10.1016/j.jpeds.2009.04.011. Epub 2009 Jun 26.

Mercury levels in premature and low birth weight newborn infants after receipt of thimerosal-containing vaccines

Michael E Pichichero  1 , Angela Gentile, Norberto Giglio, Margarita Martin Alonso, Maria Veronica Fernandez Mentaberri, Grazyna Zareba, Thomas Clarkson, Carlos Gotelli, Mariano Gotelli, Lihan Yan, John Treanor
Affiliations
Randomized Controlled Trial

Mercury levels in premature and low birth weight newborn infants after receipt of thimerosal-containing vaccines

Michael E Pichichero et al. J Pediatr. 2009 Oct.

Abstract

Objective: We conducted a population-based pharmacokinetic study to assess blood levels and elimination of mercury after vaccination of premature infants born at > or =32 and <37 weeks of gestation and with birth weight > or =2000 but <3000 g.

Study design: Blood, stool, and urine samples were obtained before vaccination and 12 hours to 30 days after vaccination from 72 premature newborn infants. Total mercury levels were measured by atomic absorption.

Results: The mean +/- standard deviation (SD) birth weight was 2.4 +/- 0.3 kg for the study population. Maximal mean +/- SD blood mercury level was 3.6 +/- 2.1 ng/mL, occurring at 1 day after vaccination; maximal mean +/- SD stool mercury level was 35.4 +/- 38.0 ng/g, occurring on day 5 after vaccination; and urine mercury levels were mostly nondetectable. The blood mercury half-life was calculated to be 6.3 (95% CI, 3.85 to 8.77) days, and mercury levels returned to prevaccination levels by day 30.

Conclusions: The blood half-life of intramuscular ethyl mercury from thimerosal in vaccines given to premature infants is substantially shorter than that of oral methyl mercury in adults. Because of the differing pharmacokinetics, exposure guidelines based on oral methyl mercury in adults may not be accurate for children who receive thimerosal-containing vaccines.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Blood mercury levels before and after receipt of vaccines that contained thimerosal preservative. Infants received intramuscular vaccines and had blood sampling before vaccination (day 0) and were randomly assigned to have samples taken at a single time point after vaccination (see “Methods”). Each data point represents 1 observation. The median values for each time point are connected by the line.
Figure 2
Figure 2
Stool mercury levels before and after receipt of vaccines that contained thimerosal preservative. Infants received intramuscular vaccines and had blood sampling before vaccination (day 0) and were randomly assigned to have samples taken at a single time point after vaccination (see “Methods”). Each data point represents 1 observation. The median values for each time point are connected by the line.
Figure 3
Figure 3
Urinary mercury levels before and after receipt of vaccines that contained thimerosal preservative. Infants received intramuscular vaccines and had blood sampling before vaccination (day 0) and were randomly assigned to have samples taken at a single time point after vaccination (see “Methods”). Each data point represents 1 observation. The median values for each time point are connected by the line.
Figure 4
Figure 4
Predicted Mercury Levels by Dose and Body Weight
Figure 4
Figure 4
Predicted Mercury Levels by Dose and Body Weight
Figure 4
Figure 4
Predicted Mercury Levels by Dose and Body Weight
See this image and copyright information in PMC

References

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    1. Pichichero ME, Gentile A, Giglio N, Clarkson T, Zareba G. Mercury Levels in Newborns and Infants After Receipt of Thimerosal-Containing Vaccines. Pediatrics. 2008;121:208–214. - PubMed

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