Adjuvants aluminiques des vaccins : analyse critique des études toxicocinétiques de référence

[Aluminium adjuvant exposure through vaccines in France in 2018]

OBJECTIVES

Aluminum-containing vaccine adjuvants stimulate an adequate immune response to vaccination. The safety and rapid elimination of these molecules, a guarantee of their safe use for several decades, have been challenged by a growing number of studies over the last 20 years. Evaluation of exposure to aluminum adjuvants of an individual is thus essential. The current review answers the following questions: what is the exposure of aluminum adjuvants of an individual vaccinated in France? What are the factors of variation?

METHODS

To evaluate the immunization exposure to aluminum for a vaccinee in France, we used the 2018 vaccination schedule and the Social Security database for vaccines reimbursed that year. French mandatory and recommended vaccines for an individual who does not travel abroad and has no particular professional obligations have been taken into account.

RESULTS

Our results show that an individual following the vaccination requirements and recommendations of 2018 receives between 2545 and 7735μg of Al³⁺ during his lifetime, and at least 50% before the age of 1year. Exposure varies with age, weight, sex, and choice of administered vaccines.

CONCLUSION

Vaccines with higher doses of aluminum are mainly injected at the beginning of life. Women receive a proportionately larger dose than men. The most reimbursed vaccines are often those with the highest amount of aluminum salts.

Aluminum in vaccines: Does it create a safety problem?

For almost a century, aluminum (Al) in the form of Al oxyhydroxide (a crystalline compound), Al hydroxyphosphate (an amorphous Al phosphate hydroxide), Al phosphate, and Al potassium sulfate has been used to improve the immunogenicity of vaccines. Al is currently included in vaccines against tetanus, hepatitis A, hepatitis B, human papillomavirus, Haemophilus influenzae type b, and infections due to Streptococcus pneumoniae and Neisseria meningitidis. Official health authorities consider the inclusion of Al in most of the presently recommended vaccines to be extremely effective and sufficiently safe. However, the inclusion of Al salts in vaccines has been debated for several years because of studies that seem to indicate that chronic Al exposure through vaccine administration can interfere with cellular and metabolic processes leading to severe neurologic diseases. Children, who in their first years of life receive several vaccine doses over a reduced period of time, would be most susceptible to any risk that might be associated with vaccines or vaccine components. The main aim of this paper was to discuss the data presently available regarding Al neurotoxicity and the risk for children receiving vaccines or other pharmaceutical preparations containing Al. Analysis of the literature showed that no apparent reason exists to support the elimination of Al from vaccines for fear of neurotoxicity. The only problem that deserves attention is the suggested relationship between Al oxyhydroxide-containing vaccines and macrophagic myofaciitis or myalgic encephalomyelitis/chronic fatigue syndrome. Currently, definitive conclusions cannot be drawn on these risks and further studies must be conducted. Until then, Al remains the best solution to improve vaccine efficacy.