Correcting this week’s misinformation: week of November 5, 2026

When well-known people get sick, it is common for anti-vaxxers to look to vaccines. This week, Senator Chris Murphy had a stroke, and Peter McCullough is blaming COVID vaccines.

• COVID illness can raise the risk of strokes, blood clots, and heart attacks.
• Vaccines help lower these COVID-related risks.
• Strokes are becoming more common in younger adults. Checking blood pressure and managing health conditions can help lower risk.

COVID itself can raise the risk of strokes, blood clots, and heart attacks. COVID vaccines can help lower these risks.

More not-so-old people are having strokes, partly because conditions like high blood pressure and diabetes are becoming more common. High blood pressure often has no warning signs, so checking it and working with a doctor can help lower stroke risk. But strokes can also happen in people without these common risks because of inherited conditions or blood clotting problems.

A 2024 study looked at more than 12.7 million older adults and about 78,600 adults with severe kidney disease. People who received the updated booster had about half the risk of COVID-related strokes, blood clots, and heart attacks compared with people who had only received the original vaccines. The risk was 47% lower in the older group and 51% lower in the kidney disease group.

Some people may confuse myocarditis with other heart conditions. Myocarditis is swelling in the heart muscle. It is a rare side effect of mRNA COVID vaccines, seen most often in teen boys and young men. Most patients’ symptoms improve with treatment and rest, often before they leave the hospital. A blood clot is a clump of blood that can block a blood vessel. If a clot blocks blood flow to part of the brain, it cuts off the oxygen that brain cells need. This can cause a stroke. 

Concerns about a rare type of blood clot were linked to a different kind of COVID vaccine, such as Johnson & Johnson and AstraZeneca. These were not mRNA vaccines. A large study of older veterans found only a very small increase in blood clot risk after vaccination of about one or two extra cases per million people.

A new article from anti-vaccine researchers, The McCullough Group, says that they found COVID vaccine DNA inside a heart tumor, proving that these vaccines cause Turbo Cancer.

• The article about COVID vaccine DNA in a tumor has not been peer-reviewed.
• The small piece of SV40 DNA used in vaccine production cannot make the virus or its cancer-linked proteins.
• There is no good evidence that COVID vaccines cause cancer. Cancer in younger adults was rising long before these vaccines existed.

The paper shared by the McCullough Group is a preprint posted on Zenodo, a website for sharing research. Zenodo is not a scientific journal. Posting a paper there does not mean other experts have checked its methods or findings. The preprint makes claims about SV40 used in making one mRNA COVID vaccine. 

SV40 is a virus found in some monkeys. It can infect humans, and certain proteins it makes can cause cancer in lab studies. Some early polio vaccines were accidentally contaminated with SV40 because the process used to kill the polio virus did not always kill SV40. However, studies have found no higher cancer risk in people who received those vaccines.

Scientists also use a small piece of SV40 DNA called a promoter in research and vaccine production. A promoter acts like an on switch, helping cells read genetic instructions. This piece is not the whole virus. It does not contain the instructions for making the proteins linked to cancer.

This DNA piece is used in making one mRNA COVID vaccine. During production, the DNA is broken down and mostly removed. Tiny pieces can remain, but they cannot make the SV40 virus or its cancer-linked proteins. 

There is no good evidence, including in this preprint, that COVID vaccines cause cancer, including what some people call turbo cancer. This claim comes partly from reports that doctors are seeing more cancer cases. But even strong cancer-causing substances can take years to cause cancer. Cancer in people under 50 has become more common, but research shows this rise was happening between 1990 and 2019, well before COVID vaccines were available.

In a video, Stephanie Seneff claims she has found glyphosate, the main ingredient in Roundup, in childhood vaccines, and that it is causing neurological problems.

• Reports of ovarian problems after vaccination do not prove the vaccine caused them.
• A Danish study of nearly 1 million girls and women found no link between HPV vaccination and early ovarian failure.
• Studies in Sweden, Scotland, and the U.S. show that HPV vaccination helps prevent cervical cancer.

Glyphosate is a chemical used to kill weeds. In 2016, Moms Across America paid a lab to test five vaccines and reported finding small amounts of glyphosate. But those results need stronger proof. The group’s own report called the testing a first screening and said more accurate tests were needed.

The lab used a test called ELISA. This test uses antibodies to look for glyphosate. It can be useful, but researchers must first show that it works correctly with the material they are testing. Other substances in a sample can affect the result. This test can cause a false positive, meaning the test reports finding glyphosate that is not actually there. The test maker recommends using another method to confirm important positive results.

The group incorrectly says that glyphosate could reach vaccines through ingredients from animals that ate treated crops. But that idea alone does not prove this happens. Research shows that mammals break down very little glyphosate and pass most of it out of their bodies rather than storing it.

Reliable testing would need to confirm both whether it is present and how much is there. A lawsuit about weed killer does not answer those questions about vaccines.