What does shedding a virus mean

For this reason, some people with immune-compromising conditions cannot receive live, weakened vaccines. Another consideration is that people not immune to the disease could get infected through viral shedding. Sometimes this is beneficial as in the case of the oral polio vaccine, which causes more than just vaccinated people to be protected against polio. This type of protection is called contact immunity. But on occasion, viral shedding can also result in an infection with symptoms, such as when an unimmunized person comes into contact with the chickenpox rash of a vaccinated person and develops a mild case of chickenpox.

The source of this confusion is twofold. First, people may not distinguish between the reproduction of a virus and the COVID vaccines causing our bodies to produce the spike protein. Second, like the whisper-down-the-lane game, talking down the line further confounds the confusion.

In sum, viral shedding is an issue when someone is infected with the virus that causes COVID, but not when they are vaccinated against it. Download a PDF version of this article.

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy. You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health.

You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel. Contact Us Online. What is viral shedding? Viral shedding and masks Because a person infected with a respiratory virus is shedding virus particles from their nose and mouth, you can quickly conclude that a mask will decrease the spread of viral particles as they are physically trapped by the mask.

Two additional aspects of masking are worth considering in the context of viral shedding: A mask also protects the person who is wearing it — Because a mask serves as a physical barrier, it offers some protection for the person wearing it.

However, people can inadvertently expose themselves if they touch a contaminated mask or other surface and then touch their eyes, nose or mouth. So, a mask worn by an infected person offers more protection than a mask worn by an uninfected person because the net result is fewer infectious viral particles circulating in the air and landing on surfaces.

Said another way, if you are healthy and susceptible and you find yourself in a situation with one mask and an infected person, give them the mask and physically distance. You will be safer than if you wear the mask yourself. Say what? Let's get something straight: The COVID vaccines do come with a list of potential side effects , but endangerment to those around you isn't among the risks. Despite the facts about these new shots, misconceptions that they cause "vaccine shedding" continue to circulate on social media, stoking fear and fueling vaccine hesitancy.

Here's what to know about vaccine shedding, and why it's not something you need to worry about when it comes to the COVID shots. Like many myths, the belief that interacting with someone who got a vaccine could potentially cause you harm stems from kernel of truth. It's a concept called viral shedding or sometimes "vaccine shedding" , a process of the body releasing viral particles from a vaccine and hypothetically creating a risk of infection to others. That's not the basis or science behind any of the vaccines we're currently using for COVID," Vincent Venditto , PhD, assistant professor of pharmaceutical sciences at the University of Kentucky College of Pharmacy, who has worked on vaccine development, tells Health.

The only way for this to potentially happen is from a live-attenuated vaccine , which means it contains a weakened version of a germ that causes a disease. These vaccines work by letting the virus replicate inside a person's body enough times to stimulate an immune response, but not cause the disease itself, per the Centers for Disease Control and Prevention CDC.

The live-attenuated vaccines currently used in the US include:. And while this type of vaccine can cause a person to shed the weakened virus often through their feces , it's extremely rare to spread enough of the germ to infect someone else with the disease. Take the flu vaccines, for example.

While researchers have discovered cases in which the weakened flu virus was transmitted from a vaccinated person to someone else, they've found no instances of that causing serious illness. Likewise, there have only been about a dozen cases of healthy vaccinated people all of whom developed a rash after their vaccine spreading the weakened virus used in the chickenpox shot to unvaccinated people around the world since , per the CDC.

For example, there was a polio vaccine that had a few cases of reported viral shedding, but it's not used in the US anymore," explains Venditto. While there is an extremely low risk of viral shedding from some vaccines causing harm to others, there's absolutely no danger when it comes to the COVID vaccines. But, by sticking to COVID-safe guidelines such as keeping an adequate distance from others, wearing a face mask, and practising hand hygiene, we can minimise the risks from a person unknowingly shedding infectious virus.

Reports of reinfection — in the sense of a new infection, rather than prolonged or intermittent shedding of the same one — have been limited to date. One source collating confirmed reinfection cases indicates there have been just 26 worldwide. Evidence we have from other coronaviruses suggests the risk of reinfection may be lower in the first 90 days after initial infection. Some studies on COVID, both published and not yet formally published in a peer-reviewed journal , suggest immunity may last for several months.

But we need more evidence on this topic, which we will accumulate as time passes. While the virus appears to be under good control in Australia, prolonged viral shedding and reinfection are probably two of the most important drivers of SARS-CoV-2 community transmission around the world. Understanding how and for how long people can shed SARS-CoV-2, and which factors increase the risk of viral shedding or reinfection, can help us to improve surveillance and reduce the rate at which the virus spreads.