‘It’s low dose of different form’ — NAFDAC reacts to claim on mercury use in vaccines

The National Agency for Food and Drug Administration and Control (NAFDAC) has debunked the claim that children in Nigeria are being administered a vaccine which contains 40 percent mercury.

According to reports online, environmental experts had made the claim at a conference held recently in Osun.

They reportedly said the vaccine was being given to children in Nigeria because it was recommended that it reduces cost.

Reacting in a statement signed by Mojisola Adeyeye, its director-general, NAFDAC described the claim as untrue, adding that protocol by the World Health Organisation (WHO) is followed on approval of vaccines in Nigeria.

The agency also said mercury is a metal and it is not used as an element 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 stabilizers,” the statement reads.

“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. 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.”

The agency said although Nigeria still receives some multi-dose vaccines which contains thimerosal, it is at the accepted concentration level.

“However, World Health Organisation has not proscribed the use of thimerosal as an inactivating agent and preservative in vaccines as there is lack of evidence that thimerosal presents risk to human health,” the statement reads.

“The WHO has closely monitored the scientific evidence relating to the use thimerosal as a vaccine preservative for over 10 years, especially through 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.

“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 review.”