The Director General of the National Agency for Food and Drug Administration and Control (NAFDAC), Prof Christianah Adeyeye, yesterday, described as false a recent report that children in Nigeria were being administered a vaccine that contains 40per cent mercury which was prescribed by a foreign organisation.
In a press statement made available to newsmen, Adeyeye, who said the statement was not true, explained that mercury was a metal, and was not used as an element or as a component of vaccines.
The statement reads in parts: “It has come to our knowledge that a statement was made that children in Nigeria were being administered a vaccine that contains 40per cent mercury which was prescribed by a foreign organisation. This statement is not true.
“Mercury is a metal, and it is not used as an element or as a component of vaccines. The basic components of vaccines are Antigens, adjuvants to improve immune response, antibiotics to prevent contamination during manufacturing, preservatives, and stabilisers.
“Thimerosal a mercuric compound which is a preservative used in multi-dose vaccines contains a different form of mercury called ethyl mercury. As a vaccine preservative, thimerosal is used in concentrations of 0.003percent to 0.01per cent, (for example, thimerosal content allowed in the vaccine is between 30 parts to a maximum of 100 parts out of million parts of the vaccine formula). Thimerosal is a mercury-based preservative that has been used for decades in the United States in multi-dose vials (vials containing more than one dose) of medicines and vaccines.
“There is no evidence of harm caused by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site. However, in July, 1999, the Public Health Service agencies, the American Academy of Paediatrics, and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure.
“Nigeria still receives some multi-dose vaccines which contain thimerosal but at accepted concentration. However, World Health Organisation (WHO) has not proscribed the use of thimerosal as an inactivating agent and preservative in vaccines as there is a lack of evidence that thimerosal presents a risk to human health.
“The WHO has closely monitored the scientific evidence relating to the use of thimerosal as a vaccine preservative for over 10 years, especially through the independent expert advisory group, the Global Advisory Committee on vaccines. The committee has constantly reached the same conclusion.
“There is no evidence to suggest that the amount of thimerosal used in vaccines poses a health risk. Other expert groups the U.S. Institute of Medicine, the American Academy of Paediatrics, the United Kingdom Committee on Safety of Medicines, and the European Agency for Evaluation of Medicinal Products have reached similar conclusions.
“NAFDAC follows WHO-approved protocol before issuing out lot release certificates before any human vaccines can be used in Nigeria, which is done after laboratory analysis and summary lot protocol