The Claim:
A tweet shared far and wide claims that COVID vaccines are made with SV40, which causes cancer.
The Facts:
SV40 is a virus that is mostly found in monkeys. In rare cases, it can infect people. Scientists once worried about it because parts of the virus can make special proteins called tumor (T) antigens. Tumor antigens are proteins that can help cancer grow.
Many years ago, some early polio vaccines were accidentally contaminated with SV40. This happened because the process used to kill the polio virus did not fully kill SV40. However, large studies following people who got those vaccines showed that they did not have higher cancer rates.
Today, a small piece of SV40 DNA called a promoter is sometimes used in labs. A promoter is a short piece of DNA that acts like an “on switch” to help cells make proteins. Only this small “on switch” part is used, not the part that makes tumor antigens. In mRNA vaccine production, this promoter may be used during manufacturing, but almost all of it is removed before the vaccine is finished. It is not considered an ingredient in the final shot.
Some studies show that mRNA vaccines, like the ones used for COVID, may help the immune system find and attack cancer cells better. The immune system is your body’s defense system that fights off sickness. Scientists are also testing how mRNA technology could be used in the future to help treat cancer. And most of us agree that cancer. is something we all want to stop.
Disclaimer: Science is always evolving and our understanding of these topics may have evolved too since this was originally posted. Be sure to check out our most recent posts and browse the latest Just the Facts Topics for the latest.
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