Correcting this week’s misinformation: week of June 18 2026

When we saw rare cases of myocarditis after COVID vaccines, many people were confused about what it meant. Anti-vaccine activists used that confusion to wrongly claim that COVID vaccines cause many kinds of serious heart problems.

A safety signal was found after rare cases of myocarditis happened in some people after vaccination. A safety signal does not mean a vaccine is unsafe. It means experts found something that needed more study.

That safety signal has since been reviewed and resolved, meaning researchers are no longer seeing extra cases with the current vaccines. The safety system worked by finding the concern, studying it, updating guidance, and continuing to check the data.

A new large study of more than 1 million veterans found that COVID vaccination was linked to better heart health outcomes. People who were vaccinated had almost a 40% lower risk of major heart problems linked to COVID. They also had about a 24% lower risk of heart problems from any cause.

These numbers describe what researchers saw across a large group of people, not what will happen to any one person. In the study, vaccinated people had about 4 fewer major COVID-related heart problems per 10 that might have happened in a similar unvaccinated group. They also had about 1 fewer heart problem from any cause for every 4 that might have happened. The benefit was strongest for people aged 75 and older and for people with other health problems, because their starting risk was higher.

During the pandemic, COVID vaccines saved lives and also saved money. The U.S. vaccination campaign is estimated to have saved $1.15 trillion by preventing more than 3.2 million deaths and millions of hospital stays.

HHS Secretary RFK Jr. recently sent a letter to a journal that had published an article that claimed vaccines cause SIDS, but later retracted the article. In the letter, RFK Jr. says he cares about “research integrity and academic freedom.” He asks the journal to explain why it removed the article.

The journal explained why the article was removed. It said there were serious problems with the way the author, Neil Z Miller, used VAERS data to suggest a link between vaccination and sudden infant death syndrome, or SIDS.

In fact, the best studies do not show that vaccines cause SIDS. Some studies found no change in SIDS risk after vaccines. Other studies found that babies who got vaccines had a lower risk of SIDS. Experts do not say vaccines prevent SIDS because families who vaccinate on time may also do other things that lower risk. But the evidence does not show that vaccines raise the risk of SIDS.

Miller using VAERS is a problem, of course. VAERS is a vaccine safety reporting system. Doctors, patients, and family members can use it to report health problems that happen after a vaccine. These reports are important because they help experts look for possible safety concerns. But a VAERS report does not prove that a vaccine caused the problem. It only means the health problem happened sometime after vaccination. More study is needed to find out whether the vaccine played a role.

This is why VAERS data must be used carefully. VAERS reports do not prove cause and effect. Reports may be incomplete, incorrect, coincidental, or hard to verify, so experts must study them with stronger research methods before drawing conclusions.

The journal said the article’s conclusions were not supported by the method used. Because the article could affect medical decisions, the editor decided it should be removed.

In an interview with an Italian journalist, former TV producer Del Bigtree says that vaccines have never been tested in “randomized placebo-controlled” trials. He says it is wrong not to do those kinds of tests.

A placebo is something used in a study to help scientists compare results. Many people think a placebo must always be saline, but that is not true.

There are two common types of comparison groups in vaccine studies. One type is an inert placebo, such as saline. This has no active ingredients. Another type is an active control. This may be another vaccine or vaccine ingredients that are already known to be safe. Active controls help scientists compare a new vaccine to something already understood.

Scientists choose the type of comparison based on the study. A saline placebo can be used when there is no vaccine that already works. But if a safe and effective vaccine already exists, it may be unethical or wrong to give some people only saline. That would leave them unprotected from a serious disease.

Giving protection is especially important for babies and children. If scientists already know a vaccine can prevent serious illness, they do not want to leave some children unprotected just to use saline in a study.

The pneumococcal vaccine is a good example. Prevnar-13 was tested against Prevnar-7, an older vaccine that already worked. If researchers had used saline instead, some children would have been left unprotected from dangerous bacterial infections. That could have put them at risk of serious illness or death. In cases like this, scientists compare a new vaccine to an older trusted vaccine. This helps them see if the new vaccine works as well or better, while still helping protect the people in the study.

Both saline placebos and active controls are accepted in science. These studies look at two main questions: Is the vaccine safe? And does it protect people from disease?

Some people claim childhood vaccines were not tested with saline placebos. That is not accurate. Many vaccines have been tested with saline placebos, including vaccines for rubella, pneumococcal disease, Hib disease, HPV, polio, measles, Tdap, and COVID.

After vaccines are approved, safety checks do not stop. Researchers keep studying vaccine safety over time and monitor millions of real-world doses.