Claims of Nigerian children being administered a vaccine that contains 40 percent mercury has been countered by the National Agency for Food and Drug Administration and Control (NAFDAC).
Prof. Mojisola Christianah Adeyeye, NAFDAC Director-General, who also played down claim of the vaccine being prescribed by a foreign organisation, noted that mercury is a metal and is not used as an element or as a component of vaccines.
Adeyeye also said that the basic components of vaccines are antigens, adjuvants to improve immune response, antibiotics to prevent contamination during manufacturing, preservatives and stabilizers.
The NAFDAC DG who stated that 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, also acknowledged that in July 1999, the Public Health Service agencies, the American Academy of Pediatrics and vaccine manufacturers agreed that thimerosal be reduced or eliminated in vaccines as a precautionary measure.
Adeyeye revealed that Nigeria still receives some multi-dose vaccines containing thimerosal but at an accepted concentration as it has not been proscribed by the World Health Organisation.
“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 0.003% to 0.01%, (for example, thimerosal content allowed in vaccine is between 30 parts to 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.”