Can You Spread COVID-19 After Getting Vaccinated?

When the vaccines for COVID-19 were first rolled out, experts—including the Centers for Disease Control and Prevention (CDC)—believed they would protect the vaccinated from getting and spreading the disease. Even CDC director Rochelle Walensky, MD, stated that "vaccinated people do not carry the virus, don't get sick" during an appearance on The Rachel Maddow Show on March 29, 2021.

Dr. Walensky was referencing data from a then-new CDC study showing that the vaccines, which were previously shown to be effective in initial clinical trials, also held up in real-world settings. This study was published in the March 29, 2021 issue of the CDC's Morbidity and Mortality Weekly Report. The study followed 3,950 health care personnel, first responders, and other essential and frontline workers, whose jobs put them at greater risk than the general population of being exposed to the virus. Of these workers, 2,479 (62.8%) received both recommended doses of either the Pfizer or Moderna vaccine, and 477 (12.1%) received only one of the doses.

For 13 weeks, between December 14, 2020, and March 13, 2021, the CDC routinely tested the workers for COVID-19 infection. The tests were done each week and as soon as anybody started to feel potential symptoms of the virus. The study participants were from six states: Arizona, Florida, Minnesota, Oregon, Texas, and Utah.

The risk of infection was reduced by 90% among those who were fully vaccinated (meaning at least two weeks had passed since their second dose). Partial vaccination also provided protective benefits, reducing the risk of infection by 80% two weeks after receiving the first dose. The risk reductions included symptomatic infections, asymptomatic infections, and pre-symptomatic infections.

So can vaccinated people still get COVID-19? And if so, can they pass the virus on to others? The short answer is yes and yes.

When a vaccinated person gets COVID-19, it's referred to as a breakthrough infection. And according to the CDC, vaccinated people experiencing breakthrough infections can be contagious and pass the virus on to others.

The good news, though, is that when a vaccinated person gets a breakthrough infection, the symptoms tend to be less severe and the illness tends to be less serious, per the CDC. This means that they are also less likely to be hospitalized or die from the breakthrough infection.

As the CDC continues to learn, through studies and real-world situations, how well COVID-19 vaccines keep people from getting and spreading the disease, they update their databases to keep the public up-to-date.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.