The rumor that COVID vaccines are causing many more cancer cases continues to circulate.

Angus Dalgleish, who had a financial interest in a competing COVID vaccine while he was speaking out against mRNA vaccines, was citing bad science when claiming contamination of synthetic DNA that “presents risks of a genomic instability which can manifest as cancers, immune disorders, and hereditary diseases.”

Vaccines do not change our molecular structure or DNA. Dr. Paul Offit explains that it’s virtually impossible for DNA fragments in COVID mRNA vaccines to cause harm, such as cancers or autoimmune diseases. He outlines three protective mechanisms in our cells that prevent these DNA fragments from causing harm: the cytoplasm’s immune mechanisms and enzymes destroy foreign DNA; the DNA fragments lack a necessary signal to enter the nucleus; and they also lack the integrase enzyme needed to integrate into our DNA.

There is no scientific evidence or plausible mechanism suggesting that these DNA fragments would alter our genome to cause cancer. No evidence supports the claim that COVID-19 vaccines cause so-called turbo cancer or any other form of cancer.

The tweet also shows a study from South Korea that said COVID vaccines might raise the risk of cancer, but experts say the study has big problems. Scientists explained that the study did not look at important factors, like how people who get vaccines are also more likely to have cancer screenings. That can make it look as though more cancers are occurring. The study also only watched people for a year, or even just a month, which is not long enough because cancers usually take many years to develop.

There is also no evidence that COVID vaccines cause cancer. Some of the most powerful carcinogens can take years to manifest in the form of cancer. And while there has been an increase in early-onset cancers, this increase started in the early 1990s, well before the introduction of COVID vaccines.

The secretly recorded interview of a CDC employee, used in Andrew Wakefield’s Vaxxed film, is again circulating.

This interview and Wakefield’s movie were based on Brian Hooker’s reanalysis of the study described in the video. A reanalysis means looking at the data from a study again, but using a different method to see if you get new results.

Hooker’s reanalysis was first published in a medical journal called the Journal of Translational Neurodegeneration. Later, the journal retracted it, saying it should not be trusted. The paper was then published again by another group, the American Association of Physicians and Surgeons. This group is very small and is known for supporting weak or questionable scientific claims.

Experts criticized Hooker’s work. They said it had serious problems and did not consider other important factors that might affect the results. They also said he used the CDC’s (Centers for Disease Control and Prevention) data in the wrong way and that his overall study design was not appropriate.

One problem was that Hooker used a cohort design, which is a study method where researchers follow groups of people over time to see how different experiences, like getting a vaccine, affect them. The original dataset, however, was meant for a case-control analysis, which compares people who already have a condition (such as autism) with people who don’t, to see what may have caused the difference. Because Hooker switched methods, his results were not reliable.

Hooker also divided the data into many smaller groups and tested them again and again. These smaller group tests are called  subset analyses. Doing too many subset analyses can lead to false positives, which are results that look like they show a real connection but actually happen just by chance. This problem is often called data dredging, and it makes weak patterns look stronger than they really are.

Hooker’s reanalysis claimed that African-American boys who got the MMR vaccine between ages 24 and 36 months were more likely to be diagnosed with autism. But these children were vaccinated later than usual. It is possible that some of them had already been diagnosed with autism, and they got the vaccine later when their parents enrolled them in early education programs that required children to be vaccinated.

Many large and careful studies do not agree with Hooker’s claim. For example, one in Denmark  followed more than 650,000 children. It found that children who got the MMR vaccine were no more likely to have autism than children who did not.

Overall, the best research shows that vaccines do not cause autism. Instead, other studies show that autism is linked to differences in how the brain develops, especially in the prefrontal cortex, the part of the brain that helps with planning, decision-making, and social behavior. These brain changes happen before birth, which means autism starts very early in development and is not caused by vaccines.

Because it has gotten a lot of attention, many parents are wondering if their babies need a hepatitis vaccine within 24 hours of being born.

Hepatitis B (Hep B) can spread through sex, but that’s not the only way it spreads. Doctors recommend giving babies the Hep B vaccine at birth because many babies were being born to mothers who didn’t know they had the infection. Scientists believe that about 30–40% of people with long-lasting (chronic) Hep B got it either when they were born or when they were very young. Only about half of mothers with Hep B are found before they give birth.

Even today, around 25,000 babies in the U.S. are born each year to moms with Hep B. If a newborn catches it, about 90% of them will stay infected for life. This raises their chances of liver disease and liver cancer later on.

There are many reasons why mothers don’t know they have Hep B. The test for Hep B is harder to understand than some other tests. A mom might get infected after her first test during pregnancy, but before giving birth. Tests can also be wrong sometimes, showing a false “negative.” Mistakes can happen too—like ordering the wrong test, reading the results wrong, or not sharing the results clearly.

Hepatitis B can also live outside the body for up to 7 days, even in dried blood. That means it can spread in other ways, too, like through bites in daycare, dirty needles, or bandages left in public places. This doesn’t happen often, but it’s still possible.

The Hep B vaccine is very safe. The most common side effects are just soreness or pain where the shot was given. Serious side effects are extremely rare—so rare that none have been proven after millions of doses. Because the vaccine is safe, and babies can get Hep B at birth or soon after, doctors give the first dose right when a baby is born.