In her confirmation hearing, Casey Means avoided clearly backing certain vaccines, saying parents should decide with their doctors. She also claimed we don’t fully know what causes autism and that questions about vaccines and autism should not be completely closed.

Vaccines protect people from serious diseases. They are not perfect, but they lower the risk of getting very sick, going to the hospital, or dying. Some people cannot get vaccines because they are too young or have weak immune systems. These people depend on others being vaccinated to stay safe.

When many people in a community are vaccinated, it creates community immunity (also called herd immunity). This helps stop diseases from spreading. If vaccination rates fall, diseases can come back. For example, measles outbreaks often happen in places where fewer people are vaccinated.

That’s how we get people who claim that, since we do not know exactly what causes autism, questions about vaccines and autism should stay open. But decades of research give us clear answers.

Scientists now know that autism mostly begins before birth and is strongly linked to genetics and early brain development. Brain differences linked to autism often appear during pregnancy, long before a child receives vaccines.

Large studies around the world have looked for a link between vaccines and autism. They have not found one. One study in Denmark followed more than 650,000 children and found that children who received the MMR vaccine were no more likely to develop autism than those who did not.

In science, we rely on strong evidence. Right now, the evidence is clear: vaccines do not cause autism, and they help protect communities from dangerous diseases.

In a video posted online, Dr. Ben Marble says vaccinated people should not donate blood because he believes the COVID-19 vaccine is dangerous, has contaminated the blood supply, and is causing serious health problems like blood clots and heart attacks.

Dr. Ben Marble is a member of a group called America’s Frontline Doctors. He has claimed that Dr. Anthony Fauci created the COVID virus and has promoted treatments such as hydroxychloroquine and ivermectin, which have not been proven to treat COVID.

Marble has not provided evidence that receiving blood from someone who has been vaccinated causes blood clots or heart attacks. A 2025 study that looked back at medical records found that receiving blood from someone who had COVID or received a COVID vaccine does not increase health risks.

Getting a COVID-19 vaccine does not affect a person’s ability to donate blood, platelets, or plasma. The American Red Cross says that people who have been vaccinated can donate as long as they feel well at the time of donation.

On his internet show, Del Bigtree claims that the Tdap vaccine given during pregnancy may be linked to stillbirth, preterm birth, and fetal death.

The study Del Bigtree refers to looked at reports in a government database called VAERS.

VAERS allows doctors, patients, or family members to report health problems that happen after vaccination. These reports do not prove the vaccine caused the problem. They only show that the event happened sometime after vaccination.

In the database, some pregnancy-related outcomes were reported more often than expected. But the study explains that VAERS data cannot show cause and effect because reports are voluntary and not verified the same way as in controlled studies.

The authors also note that the large numbers mentioned in the video come from a statistic called a reporting odds ratio. This number compares how often something is reported for one vaccine versus others in the database. It does not measure real-world risk or show that the vaccine caused the problem. If an event is rare, even a small number of reports can make the ratio look very large. The number can also change depending on how often people choose to report certain events. Because of this, reporting odds ratios are mainly used to flag issues that may need more study, not to show that a vaccine is dangerous.

Stronger research has not found a higher risk of stillbirth or fetal death from the Tdap vaccine during pregnancy. This research includes large studies that follow many people and compare what happens to those who got the vaccine and those who did not. Because these studies include many people and track real pregnancies, they are better at spotting rare problems like stillbirth or fetal death.

The Tdap vaccine is given during pregnancy because whooping cough, or pertussis, is dangerous to new babies. Before the vaccine, up to 9,000 children died from pertussis each year. Now, these deaths are rare enough to make news, but still preventable.