Can I Spread Coronavirus to Others When I Get the COVID-19 Vaccine?

Dr. Paul Offit explains why it’s not possible to spread coronavirus to others after getting the COVID-19 vaccine.


Can I spread coronavirus to others when I get the COVID-19 vaccine?

Paul Offit, MD: Hi, my name is Paul Offit. It is Tuesday, May 4th, 2021. And I'm talking to you from the Vaccine Education Center here at the Children's Hospital of Philadelphia. One question that has come up, remarkably, is, is it possible that when people get a vaccine that they can shed the virus, shed coronavirus, and therefore spread it to others?

That's not possible, and I'll explain why. When you're given a SARS-CoV-2 vaccine, whether it's the mRNA vaccines that are made by Pfizer or Moderna, or whether it's the vector virus vaccine that is made by Johnson & Johnson or AstraZeneca, you are not being inoculated with the whole virus; therefore, the virus can't possibly reproduce itself. What you're being given essentially is a gene that codes for one protein of the virus; that protein is the SARS-CoV-2 spike protein. And your cells then are essentially “educated” to make that one protein for a few days, much as your cells make proteins all the time. Your cells make hemoglobin. Your cells make insulin. It would be the same thing as saying, if I stand next to somebody who's making insulin, which is pretty much everybody who doesn't have diabetes, then I could possibly catch insulin from them, which is not possible. So, it's also the … another way to look at this is that when you're given vaccines like the hepatitis B vaccine or the human papillomavirus vaccine, which is just one protein from the virus, you can't possibly spread the virus because you are not being inoculated with the virus.

Now, there are vaccines like the oral polio vaccine, which is a live weakened form of the virus, where you can then shed the virus, and you can in fact have people who are close to you or come in close contact with you actually get exposed to that virus and develop immunity. That's called contact immunity. And if you inoculated people with the oral polio vaccine, which we don't use in the United States anymore and haven't since for the last 20 years, but if you inoculated somebody in the home with oral polio virus vaccine, about 25% of people in the home would also become immune because they would come in contact with that live, weakened form of the virus, called contact immunity — distinct from herd immunity. But that is not possible with these vaccines, where you're essentially being given genetic material that allows you only to make one protein of the virus. It's simply not possible.

Thank you.

Related Centers and Programs: Vaccine Education Center

Last Reviewed on Jun 01, 2021