Do COVID-19 Vaccines Shed?
COVID-19 vaccines can’t cause someone to spread coronavirus particles, including mRNA and spike proteins, to other people. It’s not biologically possible.
Some people worry about “shedding” after COVID-19 vaccination because they’ve heard untrue claims that simply being around someone who’s been recently vaccinated could affect another person’s menstrual cycle or fertility, lead to them having a miscarriage, alter their DNA — or any number of ailments. But that’s not how our bodies (or COVID-19 vaccines) work.
COVID-19 vaccines cannot shed. None of the COVID-19 vaccines currently used in the U.S. contain live viruses. The two types of vaccines available are mRNA vaccines (which don’t contain any virus at all) and a viral vector vaccine (which contains no live virus). Both vaccines use the body’s own cells to create a spike protein found on the virus’s surface. That’s what prompts us to make an immune response. After a short while, the mRNA and spike proteins get broken down and cleared away by the body, and not in a way that would pass them along to someone else.
There’s no biological reason to think that being around a recently vaccinated person would expose you to mRNA, spike proteins, or COVID-19. But the more people around you who are vaccinated, the lower your chances are of getting seriously sick or dying of COVID-19.