Latest news with #thimerosal
CBC
10 hours ago
- Health
- CBC
U.S. vaccine panel rejects flu shots with a specific preservative, despite safety data
The Trump administration's new vaccine advisers on Thursday endorsed this fall's flu vaccinations for just about every American — but only if they use certain shots free of a preservative that has been safely used in vaccines for decades. What is normally a routine step in preparing for the upcoming flu season drew intense scrutiny after U.S. Health Secretary Robert F. Kennedy Jr. abruptly fired the influential 17-member Advisory Committee on Immunization Practices (ACIP)and handpicked replacements that include several vaccine skeptics. The seven-member panel bucked another norm Thursday as it discussed the safety of a preservative used in less than five per cent of U.S. flu vaccinations: It deliberated based only on a presentation from an anti-vaccine group's former leader — without allowing the usual public airing of scientific data from the U.S. Centers for Disease Control and Prevention. The preservative, thimerosal, has been used for decades in certain vaccines that come in multi-dose vials, to prevent contamination as each dose is withdrawn. Its controversy stems from containing a small amount of a particular type of mercury. However, the CDC's own data shows it is safe, and on Friday the World Health Organization stated in a press briefing that there was no evidence of risk. "Thimerosal has been reviewed multiple times by multiple agencies, including WHO, and it's clear from the evidence that there is no evidence of harm from the use of thimerosal," Dr. Katherine O'Brien from WHO told reporters in reaction to the U.S. panel decision. Thimerosal contains a minute amount of ethyl mercury, which breaks down quickly in the body and is swiftly removed, unlike methyl mercury, the type of mercury found in the environment which can build up in the body and cause harm. In Canada, a handful of multi-dose influenza vaccines approved for use by Health Canada contain thimerosal, but the vast majority of routine childhood vaccines do not. Single-dose flu shots unaffected Study after study has found no evidence that thimerosal causes autism, a myth long pushed by anti-vaccine groups, or poses any safety risks. Yet since 2001, all vaccines routinely used for U.S. children age 6 years or younger have already come in thimerosal-free formulas. The advisory panel voted to back the usual U.S. recommendation that nearly everyone age six months and older get an annual flu vaccination, but then voted 5-1 with one abstention that these had to be thimerosal-free formulations. This would include single-dose shots that already are the most common type of flu vaccination, and would rule out the subset of flu vaccine dispensed in multi-dose vials. "There is still no demonstrable evidence of harm," one panelist, Dr. Joseph Hibbeln, a psychiatrist formerly with the National Institutes of Health, said in acknowledging the committee wasn't following its usual practice of acting on evidence. But he argued that "we have to respect the fear of mercury" that he said might dissuade some people from getting vaccinated. Panel blocked CDC's analysis Lyn Redwood, formerly of the Kennedy-founded anti-vaccine group Children's Health Defense, gave the presentation on thimerosal in front of the panel, arguing that it was a neurotoxin. The version of Redwood's presentation posted to the CDC's website earlier this week initially included a reference to a study that does not exist. The report she gave to the committee was significantly shorter, removing a reference to that study and another slide saying she did not have any conflicts of interest. "With the vote on thimerosal this afternoon, the new committee has turned the ACIP process into a farce," said former CDC vaccine adviser Dr. Fiona Havers, who resigned last week over Kennedy's changes to vaccine policy. Medical groups decried the panel's lack of transparency in blocking a CDC analysis of thimerosal that concluded there was no link between the preservative and neurodevelopmental disorders, including autism. The data had been posted on the committee's website Tuesday, but was later removed — because, according to ACIP member Dr. Robert Malone, the report hadn't been authorized by Kennedy's office. Panel members said they had read it. The ACIP helps the CDC determine who should be vaccinated against a long list of diseases, and when, and its recommendations have a big impact on availability and insurance coverage of vaccines in the U.S. Normally the CDC's director would decide whether to accept ACIP's recommendation, but the Senate has not yet confirmed nominee Susan Monarez. Administration officials said Kennedy would make that decision. While Thursday's debate involved only a small fraction of flu vaccines, some public health experts contend the discussion unnecessarily raised doubt about vaccine safety. Already, fewer than half of Americans get their yearly flu vaccinations, and mistrust in vaccines overall is growing. "Selective use of data and omission of established science undermines public trust and fuels misinformation," said Dr. Sean O'Leary of the American Academy of Pediatrics (AAP). He said of the new panelists, "Nothing about their recent actions have been science-based or transparent." WATCH: Misinformation one of the factors behind decline in childhood vaccination globally: Decline in childhood vaccination fuelled by global conflicts, misinformation: Lancet 3 days ago Duration 2:01 A new study published in the Lancet medical journal suggests childhood vaccinations have stagnated or declined since 2010. The authors say geopolitical instability is fuelling the drop in some countries, but misinformation is largely driving the decline in high-income countries. The pediatrics group announced Wednesday that it would no longer be participating in the ACIP meetings, with president Sue Kressly saying in a video statement that "with the committee dismissals, it is no longer a credible process." The AAP will continue publishing its own vaccination recommendations. The flu votes marked the final step of a two-day meeting that alarmed pediatricians and other doctors' groups, who pointed to new panelists' lack of expertise in how to properly track vaccine safety — and a shift in focus which appears to boost anti-vaccine messaging. Of special concern was the announcement by panel chairman Martin Kulldorff to reevaluate the "cumulative effect" of the children's vaccine schedule — the list of immunizations given at different times throughout childhood. That reflects the scientifically debunked notion that children today get too many vaccinations for their immune systems.
Fox News
12 hours ago
- Health
- Fox News
CDC committee moves to phase out controversial mercury ingredient from flu vaccines
Print Close By Melissa Rudy Published June 27, 2025 A vaccine ingredient is in the spotlight this week, as a preservative called thimerosal was included on the agenda for a meeting of the CDC's Advisory Committee on Immunization Practices (ACIP). "Presentation regarding thimerosal in vaccines" was listed as an agenda item for Thursday, June 26, followed by "Proposed recommendations regarding thimerosal-containing influenza vaccine." Thimerosal (also spelled thiomersal) is a mercury‑based preservative that has been used in multi-dose vaccines and medications since the 1930s as a means of preventing contamination, according to the CDC. CDC REMOVES COVID VACCINE RECOMMENDATION FOR HEALTHY CHILDREN AND PREGNANT WOMEN The ingredient is intended to prevent contamination by stopping the growth of bacteria and fungi, the same source states. Due to growing concerns about potential mercury exposure, the American Academy of Pediatrics, Public Health Service agencies and vaccine manufacturers agreed that thimerosal should be "reduced or eliminated in vaccines." In 2001, thimerosal was removed from all vaccines recommended for children 6 and younger — except for influenza. Today, multi-dose flu vaccines still contain thimerosal, but other versions are available without the ingredient. CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER At the June 27 meeting, the CDC's Advisory Committee on Immunization Practices voted to recommend that all adults (including pregnant women) and all children 18 years and younger should receive seasonal influenza vaccines only in single-dose formulations that do not contain thimerosal, according to meeting notes published by the CDC. Despite these recommendations, the CDC and other health agencies have claimed there is no evidence that thimerosal poses health risks. "Thimerosal use in medical products has a record of being very safe," the agency's website states. "Data from many studies show no evidence of harm caused by the low doses of thimerosal in vaccines." CLICK HERE TO GET THE FOX NEWS APP Dr. Jacob Glanville, CEO of Centivax, a San Francisco biotechnology company, reiterated that American children have not been receiving thimerosal for over 20 years in their vaccines, but that it remains in some multi-use vial vaccines, mostly outside the U.S. "We support any effort to remove it entirely — there are other preservatives that are not based on mercury," Glanville told Fox News Digital. For more Health articles, visit Glanville noted that his company's vaccines never contain mercury, aluminum, formaldehyde, or pig- or cow-derived materials. Print Close URL
Health Line
12 hours ago
- Health
- Health Line
Is Thimerosal in Flu Shots Safe? Experts Discuss CDC Vaccine Decision
A CDC advisory panel voted 5–1 to recommend only flu vaccines without the preservative thimerosal. Thimerosal is a mercury-containing compound used as a preservative in vaccines and other drugs. Doctors and physician advocacy groups warn that the decision could lead to more confusion and vaccine hesitancy. A CDC advisory committee voted 5-1 on Thursday to recommend only single-dose formulations of flu shots that do not contain the preservative thimerosal. The vote follows a shakeup of the Advisory Committee on Immunization Practices (ACIP), in which Health Secretary Robert F. Kennedy Jr. dismissed all 17 members of the panel and hand-picked their replacements. The ouster and subsequent ACIP vote have caused alarm among doctors and physician advocacy organizations—including the American Medical Association (AMA) and the American Academy of Pediatrics (AAP) — who claim the committee is stoking confusion and distrust in vaccines. 'It further undermines vaccine confidence. And they're doing this despite a massive amount of data that confirms that thimerosal is a safe and effective preservative,' said Jake Scott, MD, clinical associate professor of infectious diseases at Stanford Medicine. Thimerosal, a mercury-containing preservative, has been used since the 1930s in vaccines and other drugs. Since the 1990s, it has been the target of intense speculation and debate due to claims — now debunked — that linked it to autism and neurotoxicity. ACIP's new recommendations contradict numerous studies and decades' worth of data showing no link between thimerosal and autism or other neurological conditions. 'This decision does not appear to be data-driven at all,' said Saahir Khan, MD, PhD, an infectious disease specialist with Keck Medicine of USC. 'This will sow a lot of distrust and probably lead to reduced vaccine uptake rates because they are sending a message that indirectly says that we don't think vaccines with thimerosal are safe, whereas the evidence shows that they are safe,' Khan said. What is thimerosal? Thimerosal, which contains about 50% mercury by weight, is one of the most widely used preservatives in vaccines. Every time a drug vial is pierced, it is susceptible to bacterial and fungal contamination. Thimerosal prevents microbial growth and contamination. Today, the use of thimerosal-containing vaccines has declined due to the advent of single-dose vaccine formulations. All routinely recommended vaccines for U.S. children ages 6 and younger are available in formulations without thimerosal. The vast majority of flu shots administered last flu season, about 96%, were also free of thimerosal. ACIP's recommendation this week against thimerosal-containing flu shots applies only to vaccines packaged in multi-dose vials. While multi-dose vials make up only a small subset of flu shots, the format is important for public health. 'Multi-dose vials are cheaper, easier to deploy, and essential for equitable access. They're especially important during pandemics. They proved to be essential during the H1N1 pandemic when single-dose supplies run out a lot faster,' said Scott. Following a review in 1999, conducted as part of the FDA Modernization Act (FDAMA), the FDA, National Institutes of Health (NIH), CDC, and others recommended that thimerosal be removed from childhood vaccines as a precautionary measure. That recommendation was based on 'scientific uncertainty' at the time and sought to reduce total mercury exposure in infants. That review found ' no evidence of harm ' caused by thimerosal in vaccines beyond localized reactions. However, it noted that some infants' cumulative mercury exposure in their first six months exceeded EPA recommendations, and that removing thimerosal could reduce this overall exposure. At vaccine concentrations, thimerosal delivers roughly 25 micrograms of mercury per 0.5 mL dose — about the same amount found in a three-ounce can of tuna. However, there's also an important distinction between the mercury found in thimerosal and tuna. Certain kinds of fish contain methylmercury, which can be toxic. Thimerosal contains ethylmercury, which, in contrast, is eliminated far more rapidly from the body and thus is far less likely to persist and cause harm. Revisiting the thimerosal controversy In the lead-up to this week's vote, Lyn Redwood, a retired nurse practitioner and president emeritus of Children's Health Defense — a group formerly chaired by Robert F. Kennedy Jr., whose mission is 'ending childhood health epidemics by eliminating toxic exposures' — reiterated many claims against thimerosal in an ACIP presentation. However, those claims — especially the alleged link between thimerosal and neurotoxicity — have been extensively debunked. 'There have been multiple well-controlled studies, randomized meta-analyses, and trials comparing vaccines with thimerosal to vaccines without thimerosal to see if there was any difference in neurological outcomes, and these trials generally did not find any connection between thimerosal at the doses used in vaccines and neurological conditions,' said Khan. An often-cited Danish study that included over half a million children found no causal relationship between thimerosal and the development of autism. Another large study of more than 100,000 children in the United Kingdom also found no evidence to support a link between thimerosal and neurodevelopmental disorders. A 2010 study found that exposure to thimerosal in prenatal or infant stages did not increase the risk for autism spectrum disorder (ASD). Perhaps most telling, Scott points out, is that even after thimerosal has been removed from vaccines, autism rates continued to rise. Such was the case for Denmark, which removed thimerosal in 1991, and the United States in 2003. Doctors warn that ACIP's recommendation fails to consider these studies and the large body of evidence supporting vaccine safety. And that will inevitably have consequences for the health of Americans. 'Our studies show that vaccines are safe and effective. I recommend them based on my medical experience, but some people are going to refuse. And unfortunately, they're going to put themselves at higher risk of infection and they're going to put the people around them at higher risk of infection,' said Khan.
The Independent
14 hours ago
- Health
- The Independent
What is thimerosal? The rarely-used vaccine preservative targeted by RFK Jr
A federal vaccine panel, recently reshaped by the U.S. Health Secretary Robert F. Kennedy Jr. has voted to discourage the use of flu vaccines containing thimerosal, a mercury-based preservative. The decision marks a dramatic shift in vaccine policy, as thimerosal has long been considered safe by health agencies worldwide, with its use already limited to a few multi-dose flu shots. RFK Jr. has long linked thimerosal to autism – a connection that extensive scientific research has thoroughly debunked. Thimerosal is an organic chemical containing mercury, used as a preservative in vaccines since the 1930s. Its effect comes from the mercury that disrupts the function of enzymes in microbes, such as bacteria and fungi. This prevents contamination of vaccines while they are stored in vials. Mercury, however, is also well-known as a potent toxin acting on cells in the brain. Much of mercury's toxicity to brain cells stems from the same attributes that make thimerosal such a useful preservative. It disrupts the basic biological function of cells by changing the structure of proteins and enzymes. In the brain, this can lead neurons to become excessively active, can impair the way they use energy, it can increase inflammation and lead to the death of neurons. While mercury poisoning can damage brain function in adults, babies are even more vulnerable. People have long understood that mercury is toxic. But in the latter half of the 20th century, scientists discovered that industrial mercury entered rivers and seas, accumulating in the tissues of fish and shellfish. The neurological consequences of consuming too much contaminated seafood could be severe. This led environmental scientists to determine safe levels of mercury exposure. Anxiety about mercury in vaccines intensified when it was noticed that some children receiving multiple vaccines could exceed established safety limits for mercury exposure. These limits were based on environmental toxicity studies. How mercury affects the brain, though, depends very much on the chemical form in which it is ingested. Methylmercury v ethylmercury The form of mercury that contaminates the environment as a consequence of industrial processes is methylmercury. The form that is part of thimerosal is ethylmercury. The structure of these molecules differs in subtle but important ways. Methylmercury has one more carbon atom and two more hydrogen atoms than ethylmercury. These small differences significantly affect how each compound behaves in the body, particularly in how easily they dissolve in fats. Fat solubility is a key consideration in pharmacokinetics – the science of how drugs and other molecules travel through the body. Briefly, because cell membranes are made of fatty substances, a molecule's ability to dissolve in fats strongly influences how it crosses these membranes and moves through the body. It affects how a molecule is absorbed into the blood, how it is distributed to different tissues, how it is broken down by the body into other chemicals and how it is excreted. Methylmercury from environmental contamination is more fat-soluble than ethylmercury from thimerosal. This means that it accumulates more easily in tissues and is excreted from the body more slowly. It also means that it can more easily cross into the brain and accumulate at greater concentrations for longer. For this reason, the safety guidelines that were established for methylmercury were unlikely to accurately predict the safety of ethylmercury. Global policy shift amid public fear Nevertheless, concerns about vaccine hesitancy, rising autism diagnoses and fears of a potential link to childhood vaccines led to thimerosal being almost entirely removed from childhood vaccines in the US by 2001 and in the UK between 2003 and 2005. Beyond biological considerations, policymakers were also responding to concerns about how vaccine fears could undermine immunisation efforts and fuel the spread of infectious diseases. Denmark, which removed thimerosal from childhood vaccines in 1992, provided an early opportunity to study the issue. Researchers compared the rates of autism before and after thimerosal's removal, as well as compared with similar countries still using it. Several large studies demonstrated conclusively that thimerosal was not causing autism or neurodevelopmental harm. Despite the overwhelming evidence that thimerosal is safe, it is no longer widely used in childhood vaccines in high-income countries, replaced by preservative-free vaccines, which must be stored as a single dose per vial. Storing multiple doses of a vaccine in the same vial, however, is still an extremely useful approach in resource-limited settings, in pandemics and where diseases require rapid, large-scale vaccination campaigns, common with influenza. International health bodies, including the World Health Organization, continue to support thimerosal's use. They emphasise that the benefits of immunisation far outweigh the theoretical risks from low-dose ethylmercury exposure.
Yahoo
15 hours ago
- Health
- Yahoo
What is thimerosal, the flu vaccine ingredient targeted by RFK Jr.?
Federal vaccine advisers installed by Health and Human Services Secretary Robert F. Kennedy Jr. voted Thursday to stop recommending influenza vaccines containing thimerosal, a preservative that has been long criticized by anti-vaccine activists. Scientists and public health authorities have deemed thimerosal safe, and the vast majority of flu shots don't have it. But the removal would probably make flu vaccines more expensive and harder to receive for some Americans, public health experts said. Subscribe to The Post Most newsletter for the most important and interesting stories from The Washington Post. Medical experts say the move is the latest by Kennedy, who was a longtime anti-vaccine activist before he joined the Trump administration, to chip away at vaccine policies. Here's what to know about thimerosal: - - - What is thimerosal? Thimerosal, which the Food and Drug Administration describes as a 'mercury-containing organic compound,' is used as a preservative in vaccines to stop microbial growth and prevent contamination. Since 2001, all childhood vaccines licensed and recommended in the United States have been thimerosal-free, with the exception of some multi-dose formulations of flu vaccines. When used in vaccines, it is metabolized into ethylmercury in the body, which is vastly different from methylmercury, which can be found in fish. The levels of ethylmercury in vaccines have been found to be safe, while high levels of methylmercury can cause childhood developmental damage, medical experts and the U.S. government says. 'There is a robust body of peer-reviewed, scientific studies conducted in the United States and countries around the world that support the safety of thimerosal-containing vaccines,' the FDA writes on its website. The Centers for Disease Control and Prevention posted a 17-page document online this week saying thimerosal was safe. That document was intended to be background material for members of the Advisory Committee on Immunization Practices before its meeting and vote, according to a federal health official familiar with the document. But it was posted on the ACIP website, and then removed Wednesday. 'This document by the CDC vaccine safety office did not go through the appropriate process to be posted,' an HHS spokesperson told The Washington Post. - - - Why is thimerosal controversial? In the 1990s, amid suspicion thimerosal could be a cause behind the rising rates of autism, the U.S. Public Health Service and the American Academy of Pediatrics recommended thimerosal be removed from vaccines out of an abundance of caution and to restore public confidence. By the early 2000s, thimerosal had been removed or reduced to trace amounts in most childhood vaccines, with manufacturers increasingly using single-dose vials that did not require preservatives. Several studies have shown that there is no link between thimerosal and autism. 'There is no evidence to suggest that the amount of [thimerosal] used in vaccines poses a health risk,' according to the World Health Organization, which says other medical groups in the U.S. and Europe hold the same views. After thimerosal was removed from most childhood vaccines, autism rates have continued to rise. - - - What is the impact of removing thimerosal? It would be limited. In the most recent flu season, 94 percent of all influenza vaccines administered in U.S. were thimerosal free, according to the CDC. The rate was even higher for shots administered through two major government vaccine programs. Multi-dose vials are easier to store and use for large vaccine fairs than the single-dose counterparts. They're also less expensive, reducing waste and requiring less space to store. Public health experts said medical facilities targeted at rural areas and safety net systems could face potential shortages if they remove those vaccines, although an FDA representative at the meeting said there would be enough supply to make up for the shortfall. - - - What has Kennedy said about thimerosal? Before the meeting on Tuesday, Kennedy decried the description of thimerosal as safe, writing on X that 'I leave it to the reader to speculate as to why CDC has not performed such studies in the intervening 24 years as it dosed hundreds of millions of American children and pregnant moms with mercury-laden flu shots.' On his social media post, he cited several studies he said supported his claims - and contradicted his own agencies. Medical experts told The Post that Kennedy was misstating the science. 'It's a way to overwhelm an audience who mostly WON'T click each one to find what they are looking for,' said Jessica Malaty Rivera, an infectious-disease epidemiologist, in a text. 'Second, there is zero evidence of his claims in any of those links.' In 2015, Kennedy edited a book titled 'Thimerosal: Let the Science Speak' in which he wrote 'the evidence of thimerosal's neurotoxicity is so overwhelming and the lack of any safety data so complete that anyone who is willing to read science and who believes in the capacity for scientific methods to determine empirical truths must conclude that thimerosal causes serious brain damage.' He also noted in his introduction that he 'assembled this book' to persuade the CDC to get rid of thimerosal in any vaccines. In a speaking appearance in April 2023 challenging coronavirus mandates, Kennedy pointed to his book, calling it 'definitive' proof that thimerosal 'is the cause of all these neurological injuries.' He went on a podcast later that year, where he talked more about thimerosal. 'This particular kind of vaccine, the multi-dose vial, is going to children, little children, it's destroying their brains,' Kennedy said in a July 2023 podcast appearance. 'You can accept that or not, I'm telling you that that's my belief, and I believe my belief is strongly grounded in science.' - - - Caitlin Gilbert and Lena H. Sun contributed to this report. Related Content Dynamite outside a synagogue: Civil rights stories imperiled by federal cuts In West Virginia, Medicaid is a lifeline. GOP cuts could devastate the state. 3-pound puppy left in trash is rescued, now thriving
