With the U.S. Food and Drug Administration announcing emergency use authorization for the Johnson & Johnson single-dose COVID-19 vaccine, UCLA Health experts are continuing to share medically sound, evidence-based information about the safety and effectiveness of all of the vaccines.

Here we dispel some common myths that have cropped up.

Myth 1: I can get COVID-19 from the vaccines

Not true. You cannot get COVID-19 from the vaccines.

None of the vaccines contain the live virus that causes COVID-19. All of the vaccines increase your body’s immune response by spurring it to make antibodies that block the SARS-CoV-2 virus from entering your cells. If the virus can’t enter your cells, it can’t reproduce and make you sick.

The Pfizer and Moderna vaccines both use mRNA technology and do not contain a live virus. The Johnson & Johnson vaccine also does not contain a live virus but does contain a “viral vector” technology, which uses a harmless, inactivated cold virus to activate your body’s immune response to COVID-19.


Myth 2: I don’t need to wear a mask after getting vaccinated

Though the vaccines are highly effective, there is still a small chance of getting infected. Continue to wear a mask for everyone’s safety.

Following public health guidelines, such as wearing a face covering, practicing physical distancing and avoiding indoor crowds, remains important and the best way to keep everyone as safe as possible.

Myth 3: The vaccine could alter my DNA

No. There is no way for the COVID-19 vaccine to alter your genetic material, or DNA.

The mRNA technology used in the Pfizer and Moderna vaccines never enters the part of the cell where your DNA is located.

The Johnson & Johnson vaccine does not interact with your DNA.

Myth 4: I don’t need to get vaccinated because I’ve already had COVID-19

You should get the vaccine even if you’ve had COVID-19. It will boost your resistance against getting infected again.

Medical experts don’t yet know how long immunity will last after a person gets vaccinated. So far, clinical studies have followed patients for only a few months after vaccination. Participants in these studies will eventually be followed for two years. After that, we should know more about how long immunity lasts.

In the meantime, get vaccinated as soon as you are able. It is our best shot to keep everyone as safe as possible, prevent the spread of the virus and pave the way for a return to campus.