If Thimerosal Is Safe, Why Is It Being Removed From Vaccines?
There's a newly appointed panel of experts at the U.S. Centers for Disease Control and Prevention (CDC), freshly chosen by U.S. Health Secretary Robert F. Kennedy Jr. Called the Advisory Committee on Immunization Practices, it sets the immunization schedule for Americans. And some of the new members have histories of vaccine-skepticism.
On June 26, this panel voted to remove thimerosal from flu vaccines. The ingredient has long been the target of anti-vaccine activists, despite numerous studies showing it's safe in small amounts.
The committee's recommendation now goes to the CDC's acting director to become a formal recommendation. (Susan Monarez, President Trump's selection to head the agency, is currently undergoing confirmation hearings).
Here's how thimerosal got into vaccines, why it's being taken out, and what the latest recommendation could mean for next season's flu shots.
Thimerosal, which contains a form of mercury called ethylmercury, has been used in vaccines as a preservative since the 1930s to prevent growth of fungi and bacteria. At the time, most vaccines came in larger vials that contained multiple doses, and while the vaccine makers produced a sterile and safe product, 'each time you pierce a needle [into the vial] you are potentially introducing contaminants that can lead to infection,' says Dr. Jason Goldman, president of the American College of Physicians. 'While the vaccine itself was safe, the vials got contaminated, and there were deaths from infection. So the decision was made to put a preservative in it.'
That preservative—thimerosal—was used routinely in vaccines until 2001, when federal health officials decided to remove it from the majority of childhood vaccines. It is currently only used in flu vaccines that come in multi-dose vials. (Most of the flu vaccines in the U.S. come in single-dose syringes that do not contain thimerosal.)
Ethylmercury is cleared from the body more quickly than methylmercury, which is primarily found in deep-sea fish like tuna. Both types of mercury can be toxic to cells, particularly in the brain, but the more quickly-cleared ethylmercury has less time to cause such harm, according to the CDC.
Read More: FDA Approves a Twice-Yearly Shot to Prevent HIV
'Data from many studies show no evidence of harm caused by the low doses of thimerosal in vaccines,' the CDC's website says. That includes studies that looked at a variety of neurological and psychological outcomes, as well as autism. However, researchers say longer term data on the health effects of exposure to both types of mercury isn't completely clear yet.
In 2001, federal health officials decided to remove thimerosal from most childhood vaccines, which at the time included shots for influenza, diphtheria, tetanus, pertussis, and hepatitis B. Thimerosal remained in trace amounts in larger vials of the annual flu vaccine to protect against contamination.
Dr. Paul Offit, a member of the Advisory Committee on Immunization Practices at the time, says there were a number of reasons for the decision back then—most of which had more to do with policy pressures and optics than with concerns over health harms. In early 1998, Andrew Wakefield, a gastroenterologist in the U.K., had published a paper in which he linked the MMR vaccine for measles, mumps, and rubella to an increased risk of autism. His paper has since been debunked and his medical license has been revoked, but his findings sparked the anti-vaccine movement that continues today, despite evidence that vaccines have saved lives and provide more benefit than harm.
After Wakefield's paper gained notoriety, a U.S. Congressman asked the CDC's vaccine experts to review the data and vote whether, as Wakefield suggested, the vaccines for the three diseases should be separated and given individually to reduce any potential harm to infants. It wasn't based in science, and 'around the table we voted 'no,'' says Offit, who was part the committee.
Read More: A Study Retracted 15 Years Ago Continues to Threaten Childhood Vaccines
A few months later, vaccine maker Wyeth decided to remove RotaShield, the first vaccine to protect against rotavirus, from the market—just 10 months after it was approved. The vaccine was linked to rare bowel obstruction in some babies who had received it in their first six months. The withdrawal understandably added to the public's concerns about the safety of vaccines.
So when issues about the potential risks of mercury in thimerosal emerged, in part due to Wakefield's paper, Offit says the committee was faced with addressing Americans' growing concern that federal health agencies were not adequately ensuring vaccine safety. 'We had a vaccine that had been approved and then taken off the market; we did not buy Andrew Wakefield's notion to separate the MMR vaccine into three component parts. And now we had thimerosal,' says Offit. The committee's leader, as well as the members, 'were cognizant of the fact that it looked like were weren't paying attention to vaccine safety, or that we didn't care. Because we approved RotaShield, and we didn't listen to Andrew Wakefield.'
'My understanding was that at the time, there was essentially no evidence of any harm from thimerosal,' says Dr. Sean O'Leary, chair of the committee on infectious diseases at the American Academy of Pediatrics. 'But the concern was that it probably hasn't been studied as well as perhaps we'd like. And since we have the technology to remove it from the childhood vaccine schedule, we should go ahead and do that. But many, many people questioned that decision.'
One of them was Offit, who can't recall if there was an actual vote, but says he would have voted against removing thimerosal had there been one. Nothing about the makeup of the vaccines changed—only the formulation to package it into sterile, single-use syringes. 'It was an anti-science move,' he says. 'It did nothing to make vaccines safer—all we did was make them more expensive. We didn't explain ourselves. We didn't trust the American public to understand the nuance.'
Read More: Measles Is Now Showing Up in Wastewater
As a result, the decision to remove thimerosal was interpreted by many in the public, including anti-vaccine activists, as acknowledgement that thimerosal was unsafe and harmful. That decision, says Offit, 'gave birth to two anti vaccine groups—Moms Against Mercury and Generation Rescue. Any reasonable person would have thought, 'Why take it out so precipitously unless there was a problem?''
Because of that decision, currently only about 3% to 4% of flu vaccines in the U.S. that come in multi-dose vials contain thimerosal. And these larger vials are mostly used in rural and low-resource settings since they are less expensive than single-dose syringes. Most children who have received their immunizations at pediatrician offices for decades now have not been exposed to thimerosal. 'I don't know of any pediatric practices that use the multi-dose vials,' says O'Leary. 'It's pretty uncommon. Even if pediatricians did use the multi-dose vials, it's a non-issue because it's safe. This is a very clear effort to shine a light on this anti-vaccine trope that thimerosal is somehow dangerous.'
What concerns health experts about the new recommendation is that normal protocols governing the CDC panel's agenda and presentations weren't followed. Kennedy, a long-time vaccine skeptic, oversees the CDC and in June replaced all 17 previous members of the immunization committee with eight new members, many of whom lack expertise in vaccines and immunology. Dr. Cody Meissner, a faculty member at Dartmouth College Geisel School of Medicine, is the only pediatrician on the committee and also served on the U.S. Food and Drug Administration's expert vaccine committee. He was the only committee member to vote against the proposal to remove thimerosal from flu vaccines, telling other members that 'of all the issues that ACIP needs to focus on, this is not a big issue.'
'The real question is, why was this even brought up?' says Goldman. 'The thimerosal question has been asked and answered multiple times. We are not only re-litigating the issue, but now, instead of a fringe group refusing to accept evidence, they are now the decision makers.'
Read More: Still Not Feeling the Same After COVID-19? You're Not Alone
The CDC committee includes liaison members of experts from professional organizations who add expertise and perspective to the discussions, but aren't voting members. Many such groups, including the American Academy of Pediatrics, decided not to attend the latest committee meeting in protest over the firing of the previous members.
"We made the decision that this was an illegitimate meeting because of the way the Secretary dismissed all 17 members who were highly qualified, and hand-picked people who are a mix of COVID-19 contrarians and outright anti-vaccine folks," says O'Leary. "We decided not to legitimize the process with our presence."
The experts TIME spoke to about the latest decision say that the CDC posted a description and references for studies that have supported the safety of thimerosal in vaccines, but that it was removed from the agency's website before the committee meeting. 'I am very concerned that this committee will do everything it can to undermine the vaccine schedule and the public's trust in science and data,' says Goldman. 'If that happens, and vaccines are no longer appropriately recommended, it will lead to an increase in infections and deaths and put the entire public health system at risk.'
The recommendation is 'unprecedented,' says O'Leary, and therefore it's not clear how long manufacturers will have to comply, or what happens to existing vials that are already purchased and stored for the upcoming flu season, since they are legally approved. It's also unclear how insurers will address the change, and whether they will continue to cover flu shots from multi-dose vials containing thimerosal, which are mostly used in lower-resource settings.
A spokesperson for Sanofi Pasteur, one of the larger flu vaccine makers in the U.S., said 'a very small number of our doses supplied in the U.S. contain thimerosal. We now await the decision by the CDC on the path forward.'
It's not clear yet what impact the recommendation, if adopted, will have on vaccine supply, although since the bulk of flu shots currently do not contain thimerosal, the number of available doses shouldn't be affected. Sanofi's spokesperson anticipated that 'we will have sufficient supply of Sanofi flu vaccine to support customer preference for this season.'
Still, since lower-resource and rural settings may rely on the less expensive multi-dose vials, in these areas, supply of the vaccines could dwindle if clinics can't afford to purchase as many of the single-dose syringes. 'The big concern from my perspective is that vaccinating the entire population for influenza every year is a herculean task,' says O'Leary. 'And there have been issues over the years because of shortages for one reason or another. To eliminate roughly 5% of the flu shot supply all of a sudden shortly before flu season to me means that fewer people may get vaccinated—and more hospitalizations and deaths.'
Contact us at letters@time.com.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
an hour ago
- Yahoo
BMI Is an Awful Predictor of Early Death. We've Had a Better Option For Decades.
The 'go-to' way many clinicians measure healthy weight may be deeply flawed, according to new research. A population study from the University of Florida (UF) has found that BMI, or body mass index, is not the best option for predicting future health risks associated with weight – not by a long shot. Another method, which directly measures body fat and has been around for decades, has now put BMI to shame. It's called a bioelectrical impedance analysis (BIA). In a nationally representative analysis, those with high body fat levels, as measured by BIA, faced a 262 percent increased risk of death from heart disease compared to those with lower levels. Related: Meanwhile, BMI scores, which simply compare a person's weight to their height, failed to turn up any significant association with mortality. "Let's face it, the magnitude of risk this study shows is enormous," cardiologist Andrew Freeman, who was not involved in the study, told CNN's Sandee LaMotte. "It's scary to think that we may have been using a surrogate – BMI – that may not have been all that accurate over the years." BMI has long been used as a standard measure of obesity, endorsed by the United States Centers for Disease Control and Prevention (CDC), the National Institute of Health (NIH), the World Health Organization (WHO), the American Heart Association (AHA), and many more. In recent years, however, researchers around the world have begun to question BMI measurements, which do not consider body build, age, gender, sex, race, or ethnicity differences. Some medical organizations have even advised doctors to deemphasize the use of BMI. Health services researcher, Arch Mainous, and his colleagues at UF have now proposed a much-needed alternative, and it takes less than a minute to carry out. BIA is a direct measurement of body fat using a portable, inexpensive device. The contraption works by sending a weak electric current into body tissue to determine muscle and fat composition. The technology has been commercially available since the 1980s, but only recently have modern fitness trackers and smartwatches begun to incorporate BIA sensors. While these measurements are not perfect and are subject to variability, UF's nationally representative study suggests that this 25-year-old technology is more accurate as a health indicator than BMI. Over the course of 15 years, researchers found that adults who had high body fat, as measured by BIA, were 78 percent more likely to die of any cause than those with lower body fat levels. By contrast, higher BMI levels did not reveal any significant relationship with all-cause mortality. "This study is a game-changer," says lead author Mainous. "This is the ultimate Coke versus Pepsi test. And BMI failed." Sure, BMI is simple and easy to compute, but it comes with some serious limitations. People who are muscular, for instance, can sometimes be deemed overweight or obese. And on the flip side, those who have a normal BMI but elevated body fat percentages may be unaware that they may face added health risks, such as metabolic syndrome or type 2 diabetes. Mainous and colleagues argue that BIA is a more accurate alternative, and the devices that measure it are inexpensive and compact enough to become a regular feature of medical clinics. The UF team predicts that if their results are validated in larger and more diverse cohorts, "it is likely that measuring body fat percentage with BIA will become a standard of care". "These data will drive better discussions in the doctor's office as well as public health initiatives with the goal of improving the health of all," the researchers conclude. The study was published in the Annals of Family Medicine. There's a Critical Thing We Can All Do to Hold Alzheimer's Symptoms at Bay Ozempic Alternative Ditches The Needle And One Major Side Effect A Simple Change To Your Evening Routine Could Help You Exercise More
Yahoo
7 hours ago
- Yahoo
Senate megabill marks biggest Medicaid cuts in history
Senate Republicans on Tuesday passed the largest cuts to Medicaid since the program began in the 1960s, a move that would erode the social safety net and cause a spike in the number of uninsured Americans over the next decade. The tax and spending bill is projected to cost more than $3 trillion during that time, but it would be partially paid for with about $1 trillion in cuts to Medicaid. Almost 12 million lower-income Americans would lose their health insurance by 2034, according to the Congressional Budget Office (CBO). It still needs to pass the House again, where some moderate Republicans have expressed concerns about the cuts. The CBO was still analyzing the bill after it was released late Friday, and many last-minute changes meant a more exact forecast on coverage losses wasn't possible before the Senate rushed to vote on it. President Trump and most congressional Republicans say the reductions aren't true cuts. They argue nobody who should be on Medicaid will lose benefits. 'We're cutting $1.7 trillion in this bill, and you're not going to feel any of it,' President Trump said at the White House last week. Still, experts and health advocates say the CBO analysis confirms that despite Trump's repeated pledges to only cut waste, fraud and abuse in Medicaid, the legislation would enact an unprecedented reduction in the program currently used by more than 70 million low-income Americans. Sen. Thom Tillis (R-N.C.) made an impassioned speech on the Senate floor Sunday night warning that Trump was breaking his promise not to cut Medicaid. 'The people in the White House advising the president, they're not telling him that the effect of this bill is to break a promise,' Tillis said the day after announcing he would not seek reelection. 'I'm telling the president, you have been misinformed. You supporting the Senate mark will hurt people who are eligible and qualified for Medicaid.' Over time, the losses will blunt the significant coverage gains made under the Affordable Care Act (ACA), signed by then-President Obama in 2010. 'This bill isn't being crafted to improve health care in America, or to improve the Medicaid program, or to improve the [ACA]. The purpose of these cuts in the bill is to try to find savings to pay for tax cuts,' said Andrea Ducas, vice president of health policy at the Democratic-aligned Center for American Progress. 'It's treating these health care programs as a [piggy bank]. It's just, how do we extract as much from these programs as humanly possible so that we can find the savings to pay for tax cuts,' Ducas said. The effects of the cut could be devastating, beyond coverage losses. People who lose their Medicaid would have to pay more out of pocket, driving up medical debt and leading to them likely delaying needed treatment or medication. Hospitals would see a spike in uncompensated care and overcrowding of emergency rooms. Even people who still have insurance may not have anywhere to go for care. Hospitals, nursing homes and other providers operating on thin margins warn they could close. 'Seniors will struggle to afford long-term care. People with disabilities will lose critical healthcare coverage that allows them to work and live independently. Rural communities across America will be decimated from hospital closures, and people will lose their lives,' said Richard Besser, president and CEO of the Robert Wood Johnson Foundation and former acting director of the Centers for Disease Control and Prevention, in a statement. 'It is unfathomable to see policymakers intentionally inflict so much damage on the people they represent.' Experts said it's nearly impossible to take almost $1 trillion out of Medicaid without impacting the entire health system, not just the people who lose insurance. By design, the group that would be hit the hardest are people who gained insurance when their states expanded Medicaid under ObamaCare. 'The bill particularly attempts to undermine the Medicaid expansion,' said Jennifer Tolbert, deputy director of the program on Medicaid and the Uninsured at health policy research organization KFF. 'It doesn't exactly repeal it, but many of the provisions target both expansion states and the expansion population.' The bill would achieve its savings in various ways, but the bulk of the cuts come from a strict national work requirement and new restrictions on state-levied taxes on health providers. The provider taxes were the second-largest Medicaid cut in the House bill, after the work requirements. The cuts are even larger under the Senate design. Those changes would reduce spending by nearly $191 billion over a decade, according to the CBO estimate. States impose taxes on providers to boost their federal Medicaid contributions, which they then redirect to hospitals in the form of higher reimbursements. Limiting provider taxes is a long-held conservative goal, as they argue states are gaming the current system and driving up federal Medicaid spending. But senators representing states with poorer, rural populations have objected to the scale of the provider tax cuts, including Sens. Josh Hawley (R-Mo.), Susan Collins (R-Maine), Lisa Murkowski (R-Alaska) and Tillis. The House bill would freeze the tax rate for most states, but the Senate version would require many states to lower their existing rates. As an incentive for senators uncomfortable with the provision, the bill includes a $25 billion fund to aid rural hospitals. Overnight Monday, senators voted down an amendment from Collins to double the size of the fund and increase taxes on the ultra-wealthy, but the final version ultimately included $50 billion for the fund. Hospitals said the relief fund isn't enough to make up for the impacts of the bill, and they urged lawmakers to reject it in favor of the House version — which also would have enacted unprecedented Medicaid cuts, but was less damaging to rural providers. Even some Republicans sounded the alarm. Tillis focused his ire on the provider taxes and state-directed payments, arguing they were simply too harmful to his constituents. He warned his fellow Republicans that their support for the bill could boomerang and cost them politically. Hawley condemned the provider tax cuts and other Medicaid changes but voted for the bill anyway. Part of his reasoning, he said, was that the bill was changed to delay implementation of the cuts for another year. He also touted 'tax cuts for working families' and an extension of the Radiation Exposure Compensation Act. Hawley in a statement after the vote urged the House to pass the bill quickly, while sounding a warning on Medicaid. 'Let me be clear, I will continue to do everything in my power to reverse future cuts to Medicaid. If Republicans want to be the party of the working class, we cannot cut health insurance for working people.' The other major Medicaid change in the bill is work requirements. For the first time in the history of the Medicaid program, the bill would require beneficiaries to prove they are working or in school at least 80 hours a month to keep their health insurance starting Dec. 31, 2026. The Senate version extends the requirement to low-income parents of children older than 14, in addition to childless adults without disabilities. States can apply for a 'good faith' exemption to delay the start until 2029, but it's up to the discretion of the Trump administration to grant it. Advocates said giving the administration power to delay coverage losses has the potential to politicize the work requirements, as the White House could grant waivers to important states Republicans need to win. The work requirements are projected to save about $325 billion over a decade, because millions of people would be moved off Medicaid rolls. Nearly six million people would eventually lose Medicaid for not meeting the House bill's work requirements, according to CBO. Work requirements 'are only money savers if people lose coverage. Otherwise they wouldn't be in this bill,' Ducas said. 'I think that's pretty clearly the intent.' Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
USA Today
8 hours ago
- USA Today
How Trump's tax bill could cut Medicaid for millions of Americans
The Senate cleared President Donald Trump's domestic spending and tax cut bill that will enact steep cuts to the nation's safety-net health insurance program for low income families. In addition to delivering tax cuts and increasing immigration enforcement, what Trump has called the "Big Beautiful Bill" would cut nearly $1 trillion from Medicaid, the state-federal health program for low-income families and the disabled. The bill is projected to eliminate insurance coverage for 11.8 million people over the next decade, according to the nonpartisan Congressional Budget Office. Another 5 million could lose coverage if Congress doesn't extend the COVID-19 pandemic-era tax credits that have made Affordable Care Act plans more affordable for consumers. The legislation amounts to "the biggest rollback in health care coverage in the history of the United States," said Joan Alker, a research professor and executive director and co-founder of Georgetown University's Center for Children and Families. Vice President JD Vance, who cast the tiebreaking vote July 1 to pass the Senate bill 51-50, said in social media posts the Medicaid cuts are "immaterial" compared to savings the bill will fund through bolstered immigration enforcement. The House is scheduled to consider the legislation on July 2 in advance of Trump's self-imposed July 4th deadline for his signature domestic policy legislation. How will the legislation cut Medicaid? The legislation would require states to double eligibility checks to twice a year. And states, which administer Medicaid, would have to set up systems to verify a person's employment or exemption status. The legislation requires "able-bodied" Medicaid recipients to work 80 hours a month or qualify for an exemption, such as being a student, caregiver or having a disability. The original House version limited the work requirement to low-income adults without children, but the Senate version added the work requirement to parents of children older than 13. The legislation defines "able-bodied" people as those not medically certified as physically or mentally unfit for employment. The legislation also would strip coverage from undocumented immigrants who get Medicaid through state-funded programs. Health policy experts say more frequent eligibility checks and red tape will add administrative costs and cut off people who qualify but fall through the cracks because of administrative miscues. What do hospitals and doctors think of bill? Medicaid insures 83 million low-income children and adults, according to KFF, a health policy nonprofit. That represents more than 1 in 5 Americans. Health policy experts have warned the cuts could harm rural hospitals and doctors who serve a higher percentage of people enrolled in Medicaid. The Senate bill added a $50 billion rural health care fund, double the amount that an earlier version of the legislation proposed. Still, hospitals are "deeply disappointed" the bill cleared the Senate, said Rick Pollack, president and CEO of the American Hospital Association, a trade group. Pollack said the $1 trillion in Medicaid cuts would cause "irreparable harm to our health care system," and reduce access to care for all Americans. Hospitals are required to diagnose and stabilize anyone who visits an emergency room. Eliminating coverage of nearly 12 million Americans will "drive up uncompensated care for hospitals and health systems," Pollack said. Pollack said hospitals might be forced to cut services and staff, and patients could face longer wait times in emergency rooms. Some rural hospitals and facilities in underserved communities could close, Pollack said. Dr. Richard Besser, president and CEO of the Robert Wood Johnson Foundation, said the cuts to Medicaid and a federal food assistance program "will make our country sicker, put children at risk of going hungry and make it harder for families to afford basic necessities" while delivering tax cuts. When will the Medicaid cuts take effect? Medicaid recipients won't immediately be impacted by the legislation. The bill sets a Jan. 1, 2027, deadline for states to begin twice-a-year eligibility checks and verify work or exemption status of non-disabled enrollees. However, some states already have submitted waivers to the Centers for Medicare & Medicaid Services to begin Medicaid work requirements. CMS might choose to approve the waivers and allow some states to launch Medicaid work requirements before January 2027, Alker said. A KFF survey found nearly 2 in 3 people on Medicaid are employed full or part time, and others would qualify for an exemption from the work requirement because they are caregivers or students. Just 8% were not working due to inability to find work, retirement or other reasons, KFF said. While the bill doesn't mandate work requirements before January 2027, states will likely need to plan for big changes before then, said Jennifer Tolbert, deputy director of the KFF program on Medicaid and the uninsured. States will need to prepare for smaller Medicaid payments from the federal government while adding the extra administrative duties of verifying an enrollee's work or volunteer status. "Some states are anticipating this reduced revenue," Tolbert said. "At the same time, they are also required to make pretty costly changes to their eligibility systems." 'Death by a trillion cuts': Health care workers lobby Republicans in Congress Johannah Alabi's days usually consist of feeding, bathing, and caring for residents at two nursing homes in Bloomfield, Conn. She said most of her patients depend on government health insurance programs, so she is concerned about what will happen to them and her job if Trump signs the bill into law. Medicaid is the primary payer for 63% of nursing home facility residents and an additional 13% rely on Medicare as their primary payer, according to KFF, a health policy nonprofit headquartered in San Francisco. 'If some of that money is going to be taken away, something has to give,' Alabi said. 'It's going to come down to the resident care. It's going to come down to the food. It's going to come down to the activities.' That's why she was inspired to join Service Employees International Union members to lobby lawmakers to vote against the bill last week. They arrived at the Capitol with signs reading, 'Death by a trillion cuts,' and wearing shirts with the message, 'Republican cuts kill.' Jennifer Woods, another SEIU member who works in the claims department at Kaiser Permanente, ran into Sen. Ted Cruz, R-Texas, during her trip to Washington. She said she tried to explain how cuts could 'ruin people's lives' and potentially lead to some patients' deaths as she followed him through the Capitol building. 'He just shook his head and would keep going,' Woods said. 'He didn't really say anything. None of them did.'
