While the CDC weighs the shots without Thimérosal, here is what you need to know: photos

The federal government may soon recommend that people only receive influenza vaccines made without ingredient called Thimérosal.

The curator has been absent from the majority of flu vaccines for almost two decades, but has been on the agenda of a committee which advises the Centers for Disease Control and Prevention on vaccine policy.

The June meeting has been the first since the month earlier, when the Secretary of Health, Robert F. Kennedy Jr., dismissed the 17 previous members of the Consultative Committee on Vaccination Practices, or ACIP, and has installed his own seven list.

The Thimérosal was the target of groups that question the safety of vaccines. It is despite “a long safe and effective use record” as a vaccine curator, according to the Food and Drug Administration.

In three separate voices, the AIPI has recommended to children, pregnant women and all adults receive vaccinations against unique dose flu with vaccines that do not contain Thimérosal. The next step would be a decision by Kennedy or the CDC on the recommendations.

“It’s a bit like they transformed this meeting by solving a problem that no longer really exists,” said Dr. Jesse Goodman, former FDA chief scientist who is now at Georgetown University.

The only member of the committee to vote against the recommendations was Dr Cody Meissner, professor of pediatrics at Dartmouth College.

“Of all the problems on which the AIPI must concentrate, it is not a big problem,” he said. “The risk of flu is much greater than the nonexistent risk, to our knowledge, the risk of Thimérosal.”

He added: “There is no scientific evidence that Thimérosal caused a problem.”

But what is Thimérosal and what would happen if it is indeed forbidden to vaccinations against flu? Here are four things to know.

1. It is a curator who contains mercury

Thimérosal is a chemical compound which represents around 50% of mercury in weight, according to the FDA, and has been used in quantities of traces as preservative in vaccines and drugs since the 1930s.

The compound is used in bottles containing several doses of flu vaccine. His work is to prevent the bottle from contaminating themselves between patients and potentially get some patient, explains Dr. Michelle tax, clinical director of the Association of Immunization Managers.

“If you are constantly entering and out of the bottle to write a new dose, you run the risk of putting bacteria or mushrooms in this bottle,” explains tax. “And we don’t want these vaccines to be contaminated.”

She says that although most influenza vaccines come today in pre-filled syringes at a single dose, multi-purpose bottles are cheaper and take up less space in refrigerators. So, for some health centers, they are more practical.

“When we enter the flu season, it is not uncommon to get your entire flu vaccine in advance at the start of the season. And sometimes storage in the refrigerator can be a problem,” said tax.

However, they are not common. According to the CDC, 94% of flu vaccines during the 2024-25 season were without Thimérosal or reduced by Thimérosal.

2. The Thimérosal has rarely used since 2001

In 1997, the FDA modernization law forced the government to assess mercury in infant vaccines.

But the Heavy Metal presents itself in different forms. Methylmercurus is the compound found in seafood which does not decompose easily and can be toxic. Ethylmercure, the form in thimerosal, has a different risk profile.

“This did not distinguish between this type of mercury and ethylmercure, which is a form of mercury which is very quickly managed by the body and eliminated through the kidneys,” explains tax. “And ethylmercure is the place where thimérosal is derived.”

The Thimérosal was withdrawn from most infant vaccines in 2001, even if there was no evidence showing that this caused damage to the beneficiaries of the vaccines, says tax.

3. He has a discredited link with autism

The concerns that vaccines cause autism are from a 1998 study now retracted by Dr. Andrew Wakefield, who focused on the ROR vaccine against measles, mumps and rubella. Wakefield has lost its medical license and The BMJ, A leading medical newspaper called it a “elaborate fraud” in an editorial in 2011.

Despite this, speculations on a link between vaccines and autism – once defended by Kennedy himself – continued and widened to include Thimérosal, even if a link with autism has been refuted several times.

A 2004 report published by the National Academies of Sciences Engineering and Medicine reiterated that Thimérosal was not associated with autism. Subsequent studies in 2006, 2007, 2009 and 2010 showed that Thimérosal was not associated with autism or neurophysiological problems, according to the CDC.

In addition, Georgetown Goodman stresses that despite the withdrawal of Thimeralal from most vaccines, autism rates have continued to increase in the past 20 years “, which would certainly not be coherent with having something to do with infant vaccines.”

4. Most people will not notice if the thimérosal is no longer recommended in gunshots

Since most flu vaccines are administered with single dose syringes, most people will probably not notice this fall and this winter if the CDC decides to effectively prohibit Thimérosal, says tax.

However, a prohibition of Thimérosal could present certain challenges because the health centers are starting to order flu vaccines in February for the next flu season. Manufacturers may have to exchange them.

Sanofi, which makes multidose bottles of a vaccine called fluzone as well as single dose syringes, says that only a “very small number” of its doses contains thimérosal. “We recognize the recommendation of the new AIPI. We are now awaiting the CDC decision on the path to follow. We will have a sufficient supply of Sanofi flu vaccine to support customer preference for this season.”

Seqirus, the other company that manufactures multidose flasks of influenza vaccine containing Thimérosal, said in a statement at NPR that they “represent a very low proportion” of its total supply of vaccines. “We are committed to supporting our customers in the transition entirely to single dose syringes and does not expect impacts for our supply or our shipping calendar this season.”

The committee process could be a sign of things to come

Tax, of the Association of Immunization Managers, said that the committee’s decision to recommend only shots at the unique dose flu without Thimérosal shows that it is willing to make a decision without following the protocol and considering scientific evidence.

“Will it be the norm now?” she said. “It’s very worrying if that’s where it goes.”

Goodman is also concerned that these movements will ultimately know confidence in vaccines in the United States and abroad.

“One of my real concerns is that although the influenza vaccines are not perfect, they save lives. When they are given, they are always underused,” he said. “If there is more difficulty in accessing it or offering them, in the end, people would injure themselves.”