Jake Scott, Stanford University

In the four months since he began serving as secretary of the Department of Health and Human Services, Robert F. Kennedy Jr. has made many public statements about vaccines that have cast doubt on their safety and on the objectivity of long-standing processes established to evaluate them.

Many of these statements are factually incorrect. For example, in a newscast aired on June 12, 2025, Kennedy told Fox News viewers that 97% of federal vaccine advisers are on the take. In the same interview, he also claimed that children receive 92 mandatory shots. He has also widely claimed that only COVID-19 vaccines, not other vaccines in use by both children and adults, were ever tested against placebos and that “nobody has any idea” how safe routine immunizations are.

As an infectious disease physician who curates an open database of hundreds of controlled vaccine trials involving over 6 million participants, I am intimately familiar with the decades of research on vaccine safety. I believe it is important to correct the record – especially because these statements come from the official who now oversees the agencies charged with protecting Americans’ health.

Do children really receive 92 mandatory shots?

In 1986, the childhood vaccine schedule contained about 11 doses protecting against seven diseases. Today, it includes roughly 50 injections covering 16 diseases. State school entry laws typically require 30 to 32 shots across 10 to 12 diseases. No state mandates COVID-19 vaccination. Where Kennedy’s “92 mandatory shots” figure comes from is unclear, but the actual number is significantly lower.

From a safety standpoint, the more important question is whether today’s schedule with additional vaccines might be too taxing for children’s immune systems. It isn’t, because as vaccine technology improved over the past several decades, the number of antigens in each vaccine dose is much lower than before.

Antigens are the molecules in vaccines that trigger a response from the immune system, training it to identify the specific pathogen. Some vaccines contain a minute amount of aluminum salt that serves as an adjuvant – a helper ingredient that improves the quality and staying power of the immune response, so each dose can protect with less antigen.

Those 11 doses in 1986 delivered more than 3,000 antigens and 1.5 milligrams of aluminum over 18 years. Today’s complete schedule delivers roughly 165 antigens – which is a 95% reduction – and 5-6 milligrams of aluminum in the same time frame. A single smallpox inoculation in 1900 exposed a child to more antigens than today’s complete series.

Since 1986, the United States has introduced vaccines against Haemophilus influenzae type b, hepatitis A and B, chickenpox, pneumococcal disease, rotavirus and human papillomavirus. Each addition represents a life-saving advance.

The incidence of Haemophilus influenzae type b, a bacterial infection that can cause pneumonia, meningitis and other severe diseases, has dropped by 99% in infants. Pediatric hepatitis infections are down more than 90%, and chickenpox hospitalizations are down about 90%. The Centers for Disease Control and Prevention estimates that vaccinating children born from 1994 to 2023 will avert 508 million illnesses and 1,129,000 premature deaths.

Placebo testing for vaccines

Kennedy has asserted that only COVID-19 vaccines have undergone rigorous safety trials in which they were tested against placebos. This is categorically wrong.

Of the 378 controlled trials in our database, 195 compared volunteers’ response to a vaccine with their response to a placebo. Of those, 159 gave volunteers only a salt water solution or another inert substance. Another 36 gave them just the adjuvant without any viral or bacterial material, as a way to see whether there were side effects from the antigen itself or the injection. Every routine childhood vaccine antigen appears in at least one such study.

The 1954 Salk polio trial, one of the largest clinical trials in medical history, enrolled more than 600,000 children and tested the vaccine by comparing it with a salt water control. Similar trials, which used a substance that has no biological effect as a control, were used to test Haemophilus influenzae type b, pneumococcal, rotavirus, influenza and HPV vaccines.

Once an effective vaccine exists, ethics boards require new versions be compared against that licensed standard because withholding proven protection from children would be unethical.

How unknown is the safety of widely used vaccines?

Kennedy has insisted on multiple occasions that “nobody has any idea” about vaccine safety profiles. Of the 378 trials in our database, the vast majority published detailed safety outcomes.

Beyond trials, the U.S. operates the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink and the PRISM network to monitor hundreds of millions of doses for rare problems. The Vaccine Adverse Event Reporting System works like an open mailbox where anyone – patients, parents, clinicians – can report a post-shot problem; the Vaccine Safety Datalink analyzes anonymized electronic health records from large health care systems to spot patterns; and PRISM scans billions of insurance claims in near-real time to confirm or rule out rare safety signals.

These systems led health officials to pull the first rotavirus vaccine in 1999 after it was linked to bowel obstruction, and to restrict the Johnson & Johnson COVID-19 vaccine in 2021 after rare clotting events. Few drug classes undergo such continuous surveillance and are subject to such swift corrective action when genuine risks emerge.

The conflicts of interest claim

On June 9, Kennedy took the unprecedented step of dissolving vetted members of the Advisory Committee on Immunization Practices, the expert body that advises the CDC on national vaccine policy. He has claimed repeatedly that the vast majority of serving members of the committee – 97% – had extensive conflicts of interest because of their entanglements with the pharmaceutical industry. Kennedy bases that number on a 2009 federal audit of conflict-of-interest paperwork, but that report looked at 17 CDC advisory committees, not specifically this vaccine committee. And it found no pervasive wrongdoing – 97% of disclosure forms only contained routine paperwork mistakes, such as information in the wrong box or a missing initial, and not hidden financial ties.

Reuters examined data from Open Payments, a government website that discloses health care providers’ relationships with industry, for all 17 voting members of the committee who were dismissed. Six received no more than US$80 from drugmakers over seven years, and four had no payments at all.

The remaining seven members accepted between $4,000 and $55,000 over seven years, mostly for modest consulting or travel. In other words, just 41% of the committee received anything more than pocket change from drugmakers. Committee members must divest vaccine company stock and recuse themselves from votes involving conflicts.

A term without a meaning

Kennedy has warned that vaccines cause “immune deregulation,” a term that has no basis in immunology. Vaccines train the immune system, and the diseases they prevent are the real threats to immune function.

Measles can wipe immune memory, leaving children vulnerable to other infections for years. COVID-19 can trigger multisystem inflammatory syndrome in children. Chronic hepatitis B can cause immune-mediated organ damage. Preventing these conditions protects people from immune system damage.

Today’s vaccine panel doesn’t just prevent infections; it deters doctor visits and thereby reduces unnecessary prescriptions for “just-in-case” antibiotics. It’s one of the rare places in medicine where physicians like me now do more good with less biological burden than we did 40 years ago.

The evidence is clear and publicly available: Vaccines have dramatically reduced childhood illness, disability and death on a historic scale.

Jake Scott, Clinical Associate Professor of Infectious Diseases, Stanford University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Ryan Shandler, Georgia Institute of Technology; Anthony J. DeMattee, Emory University, and Bruce Schneier, Harvard Kennedy School

American democracy runs on trust, and that trust is cracking.

Nearly half of Americans, both Democrats and Republicans, question whether elections are conducted fairly. Some voters accept election results only when their side wins. The problem isn’t just political polarization – it’s a creeping erosion of trust in the machinery of democracy itself.

Commentators blame ideological tribalism, misinformation campaigns and partisan echo chambers for this crisis of trust. But these explanations miss a critical piece of the puzzle: a growing unease with the digital infrastructure that now underpins nearly every aspect of how Americans vote.

The digital transformation of American elections has been swift and sweeping. Just two decades ago, most people voted using mechanical levers or punch cards. Today, over 95% of ballots are counted electronically. Digital systems have replaced poll books, taken over voter identity verification processes and are integrated into registration, counting, auditing and voting systems.

This technological leap has made voting more accessible and efficient, and sometimes more secure. But these new systems are also more complex. And that complexity plays into the hands of those looking to undermine democracy.

In recent years, authoritarian regimes have refined a chillingly effective strategy to chip away at Americans’ faith in democracy by relentlessly sowing doubt about the tools U.S. states use to conduct elections. It’s a sustained campaign to fracture civic faith and make Americans believe that democracy is rigged, especially when their side loses.

This is not cyberwar in the traditional sense. There’s no evidence that anyone has managed to break into voting machines and alter votes. But cyberattacks on election systems don’t need to succeed to have an effect. Even a single failed intrusion, magnified by sensational headlines and political echo chambers, is enough to shake public trust. By feeding into existing anxiety about the complexity and opacity of digital systems, adversaries create fertile ground for disinformation and conspiracy theories.

Testing cyber fears

To test this dynamic, we launched a study to uncover precisely how cyberattacks corroded trust in the vote during the 2024 U.S. presidential race. We surveyed more than 3,000 voters before and after election day, testing them using a series of fictional but highly realistic breaking news reports depicting cyberattacks against critical infrastructure. We randomly assigned participants to watch different types of news reports: some depicting cyberattacks on election systems, others on unrelated infrastructure such as the power grid, and a third, neutral control group.

The results, which are under peer review, were both striking and sobering. Mere exposure to reports of cyberattacks undermined trust in the electoral process – regardless of partisanship. Voters who supported the losing candidate experienced the greatest drop in trust, with two-thirds of Democratic voters showing heightened skepticism toward the election results.

But winners too showed diminished confidence. Even though most Republican voters, buoyed by their victory, accepted the overall security of the election, the majority of those who viewed news reports about cyberattacks remained suspicious.

The attacks didn’t even have to be related to the election. Even cyberattacks against critical infrastructure such as utilities had spillover effects. Voters seemed to extrapolate: “If the power grid can be hacked, why should I believe that voting machines are secure?”

Strikingly, voters who used digital machines to cast their ballots were the most rattled. For this group of people, belief in the accuracy of the vote count fell by nearly twice as much as that of voters who cast their ballots by mail and who didn’t use any technology. Their firsthand experience with the sorts of systems being portrayed as vulnerable personalized the threat.

It’s not hard to see why. When you’ve just used a touchscreen to vote, and then you see a news report about a digital system being breached, the leap in logic isn’t far.

Our data suggests that in a digital society, perceptions of trust – and distrust – are fluid, contagious and easily activated. The cyber domain isn’t just about networks and code. It’s also about emotions: fear, vulnerability and uncertainty.

Firewall of trust

Does this mean we should scrap electronic voting machines? Not necessarily.

Every election system, digital or analog, has flaws. And in many respects, today’s high-tech systems have solved the problems of the past with voter-verifiable paper ballots. Modern voting machines reduce human error, increase accessibility and speed up the vote count. No one misses the hanging chads of 2000.

But technology, no matter how advanced, cannot instill legitimacy on its own. It must be paired with something harder to code: public trust. In an environment where foreign adversaries amplify every flaw, cyberattacks can trigger spirals of suspicion. It is no longer enough for elections to be secure − voters must also perceive them to be secure.

That’s why public education surrounding elections is now as vital to election security as firewalls and encrypted networks. It’s vital that voters understand how elections are run, how they’re protected and how failures are caught and corrected. Election officials, civil society groups and researchers can teach how audits work, host open-source verification demonstrations and ensure that high-tech electoral processes are comprehensible to voters.

We believe this is an essential investment in democratic resilience. But it needs to be proactive, not reactive. By the time the doubt takes hold, it’s already too late.

Just as crucially, we are convinced that it’s time to rethink the very nature of cyber threats. People often imagine them in military terms. But that framework misses the true power of these threats. The danger of cyberattacks is not only that they can destroy infrastructure or steal classified secrets, but that they chip away at societal cohesion, sow anxiety and fray citizens’ confidence in democratic institutions. These attacks erode the very idea of truth itself by making people doubt that anything can be trusted.

If trust is the target, then we believe that elected officials should start to treat trust as a national asset: something to be built, renewed and defended. Because in the end, elections aren’t just about votes being counted – they’re about people believing that those votes count.

And in that belief lies the true firewall of democracy.

Ryan Shandler, Professor of Cybersecurity and International Relations, Georgia Institute of Technology; Anthony J. DeMattee, Data Scientist and Adjunct Instructor, Emory University, and Bruce Schneier, Adjunct Lecturer in Public Policy, Harvard Kennedy School

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Gregory J. Dick, University of Michigan

Federal scientists released their annual forecast for Lake Erie’s harmful algal blooms on June 26, 2025, and they expect a mild to moderate season. However, anyone who comes in contact with toxic algae can face health risks. And 2014, when toxins from algae blooms contaminated the water supply in Toledo, Ohio, was a moderate year, too.

We asked Gregory J. Dick, who leads the Cooperative Institute for Great Lakes Research, a federally funded center at the University of Michigan that studies harmful algal blooms among other Great Lakes issues, why they’re such a concern.

1. What causes harmful algal blooms?

Harmful algal blooms are dense patches of excessive algae growth that can occur in any type of water body, including ponds, reservoirs, rivers, lakes and oceans. When you see them in freshwater, you’re typically seeing cyanobacteria, also known as blue-green algae.

These photosynthetic bacteria have inhabited our planet for billions of years. In fact, they were responsible for oxygenating Earth’s atmosphere, which enabled plant and animal life as we know it.

Algae are natural components of ecosystems, but they cause trouble when they proliferate to high densities, creating what we call blooms.

Harmful algal blooms form scums at the water surface and produce toxins that can harm ecosystems, water quality and human health. They have been reported in all 50 U.S. states, all five Great Lakes and nearly every country around the world. Blue-green algae blooms are becoming more common in inland waters.

The main sources of harmful algal blooms are excess nutrients in the water, typically phosphorus and nitrogen.

Historically, these excess nutrients mainly came from sewage and phosphorus-based detergents used in laundry machines and dishwashers that ended up in waterways. U.S. environmental laws in the early 1970s addressed this by requiring sewage treatment and banning phosphorus detergents, with spectacular success.

Today, agriculture is the main source of excess nutrients from chemical fertilizer or manure applied to farm fields to grow crops. Rainstorms wash these nutrients into streams and rivers that deliver them to lakes and coastal areas, where they fertilize algal blooms. In the U.S., most of these nutrients come from industrial-scale corn production, which is largely used as animal feed or to produce ethanol for gasoline.

Climate change also exacerbates the problem in two ways. First, cyanobacteria grow faster at higher temperatures. Second, climate-driven increases in precipitation, especially large storms, cause more nutrient runoff that has led to record-setting blooms.

2. What does your team’s DNA testing tell us about Lake Erie’s harmful algal blooms?

Harmful algal blooms contain a mixture of cyanobacterial species that can produce an array of different toxins, many of which are still being discovered.

When my colleagues and I recently sequenced DNA from Lake Erie water, we found new types of microcystins, the notorious toxins that were responsible for contaminating Toledo’s drinking water supply in 2014.

These novel molecules cannot be detected with traditional methods and show some signs of causing toxicity, though further studies are needed to confirm their human health effects.

We also found organisms responsible for producing saxitoxin, a potent neurotoxin that is well known for causing paralytic shellfish poisoning on the Pacific Coast of North America and elsewhere.

Saxitoxins have been detected at low concentrations in the Great Lakes for some time, but the recent discovery of hot spots of genes that make the toxin makes them an emerging concern.

Our research suggests warmer water temperatures could boost its production, which raises concerns that saxitoxin will become more prevalent with climate change. However, the controls on toxin production are complex, and more research is needed to test this hypothesis. Federal monitoring programs are essential for tracking and understanding emerging threats.

3. Should people worry about these blooms?

Harmful algal blooms are unsightly and smelly, making them a concern for recreation, property values and businesses. They can disrupt food webs and harm aquatic life, though a recent study suggested that their effects on the Lake Erie food web so far are not substantial.

But the biggest impact is from the toxins these algae produce that are harmful to humans and lethal to pets.

The toxins can cause acute health problems such as gastrointestinal symptoms, headache, fever and skin irritation. Dogs can die from ingesting lake water with harmful algal blooms. Emerging science suggests that long-term exposure to harmful algal blooms, for example over months or years, can cause or exacerbate chronic respiratory, cardiovascular and gastrointestinal problems and may be linked to liver cancers, kidney disease and neurological issues.

In addition to exposure through direct ingestion or skin contact, recent research also indicates that inhaling toxins that get into the air may harm health, raising concerns for coastal residents and boaters, but more research is needed to understand the risks.

The Toledo drinking water crisis of 2014 illustrated the vast potential for algal blooms to cause harm in the Great Lakes. Toxins infiltrated the drinking water system and were detected in processed municipal water, resulting in a three-day “do not drink” advisory. The episode affected residents, hospitals and businesses, and it ultimately cost the city an estimated US$65 million.

4. Blooms seem to be starting earlier in the year and lasting longer – why is that happening?

Warmer waters are extending the duration of the blooms.

In 2025, NOAA detected these toxins in Lake Erie on April 28, earlier than ever before. The 2022 bloom in Lake Erie persisted into November, which is rare if not unprecedented.

Scientific studies of western Lake Erie show that the potential cyanobacterial growth rate has increased by up to 30% and the length of the bloom season has expanded by up to a month from 1995 to 2022, especially in warmer, shallow waters. These results are consistent with our understanding of cyanobacterial physiology: Blooms like it hot – cyanobacteria grow faster at higher temperatures.

5. What can be done to reduce the likelihood of algal blooms in the future?

The best and perhaps only hope of reducing the size and occurrence of harmful algal blooms is to reduce the amount of nutrients reaching the Great Lakes.

In Lake Erie, where nutrients come primarily from agriculture, that means improving agricultural practices and restoring wetlands to reduce the amount of nutrients flowing off of farm fields and into the lake. Early indications suggest that Ohio’s H2Ohio program, which works with farmers to reduce runoff, is making some gains in this regard, but future funding for H2Ohio is uncertain.

In places like Lake Superior, where harmful algal blooms appear to be driven by climate change, the solution likely requires halting and reversing the rapid human-driven increase in greenhouse gases in the atmosphere.

Gregory J. Dick, Professor of Biology, University of Michigan

This article is republished from The Conversation under a Creative Commons license. Read the original article.