When Are You Most Contagious With COVID? - GoodRx (2024)



Getting sick with COVID-19 isn’t easy. Even with a mild case, on top of feeling sick, you have to contend with isolation. If you’re sick, staying home protects everyone in your community. But when can you finally go back to your usual business? With so much conflicting information, it can be hard to know when you’re actually contagious with COVID-19 and when it’s safe to go back to your routines.

People with COVID-19 illness are most contagious for the first 5 days of their illness. But that actually means they’re most contagious 1 to 2 days before they develop symptoms and until 2 to 3 days after their symptoms start. So how can you decide when to start and end your isolation? Here’s everything you need to know about when you’re most contagious with COVID-19.

How long is someone with COVID-19 infectious?

The short answer is that you’re contagious with COVID-19 for about 10 days after you come in contact with the virus. The full answer is more complicated.

The 10-day mark seems to apply to people who have mild to moderate COVID-19 illness.

But people with severe cases of COVID-19 illness can remain infectious for several weeks. There’s evidence that these people are still contagious for up to 1 month. There’s also evidence that people with a weakened immune system are infectious for longer.

On the other hand, some people stop being contagious faster. This seems to be the case for people who are fully vaccinated against COVID-19 and get a breakthrough infection. Studies show these people are contagious for a few days.

Are some variants of the virus more contagious than others?

Yes, some variants are more contagious than others. That’s why variants keep replacing one another as the most dominant strain.

The Omicron variant is more contagious than the Delta variant, which is more contagious than the Alpha (original) COVID-19 variant.

What is viral shedding?

Viral shedding is a process where people release copies of the COVID-19 virus from their body. In general, if you’re shedding the COVID-19 virus — then you’re contagious.

People typically shed COVID-19 for about 14 days, starting 2 to 3 days before they develop symptoms.

You can assume you’re shedding COVID-19 if:

• You have a fever.

• Your COVID-19 symptoms haven’t gotten better yet.

But you can’t rely on symptoms alone to tell you if you’re shedding COVID-19. Some people who get sick with COVID-19 never develop any symptoms. These people are still contagious.

That’s why experts recommend getting tested for COVID-19 if you’ve been exposed to someone with COVID-19, even if you have no symptoms.

When do you become contagious after exposure to COVID-19?

It’s not clear when people become contagious after exposure to COVID-19. That’s because the answer is different for each person.

Not everyone who gets exposed to COVID-19 picks up the virus. For example, people who are fully vaccinated are much less likely to pick up the virus.

But people who do pick up the virus start feeling sick 2 to 14 days after getting exposed to COVID-19. Since you’re contagious even before feeling sick, you can be infectious as soon as the day after you’re exposed to the virus. And it can take up to 12 days.

When do you stop being contagious if you have COVID-19?

It depends. If you have a mild illness and your symptoms are getting better, you’re probably not contagious after 10 days.

If you have a severe illness or a weakened immune system, you can be contagious for up to 3 weeks.

If you’ve been fully vaccinated against COVID-19, you may only be contagious for a few days, even if you have a weakened immune system.

And testing alone can’t tell you if you’re still contagious. So how can you know if you’re contagious?

The CDC can help. If you get sick with COVID-19 or if you’re exposed to COVID-19, use the CDC Isolation and Exposure Calculator.

The calculator will tell you when to test and how long you should isolate and wear a mask. The calculator also adjusts your isolation period based on your symptoms and whether you’ve been fully vaccinated.

At first the CDC recommended the same amount of isolation time for everyone. This method gave a simple answer, but it also made many people isolate for longer than they probably needed to.

Now the CDC offers more individual guidance. This guidance makes it easier and faster for people to get back to normal. But it also makes it impossible to give one answer that applies to everyone. Using the CDC Isolation and Exposure Calculator will quickly give you the specific answers you need.

Keep in mind that the calculator isn’t designed for people who have severe COVID-19 illness or for those with a weakened immune system. In these cases, people need to talk to their healthcare provider to come up with a strategy for ending their isolation.

Do people vaccinated against COVID become contagious if they get sick with COVID?

People who are fully vaccinated against COVID-19 can still get sick. But they’re much less likely to get a serious illness. They’re also less contagious if they get sick.

Getting vaccinated against COVID-19 not only protects you, it protects everyone around you. It helps stop the spread of COVID-19, and it’s the best way to protect yourself and your loved ones.

Bottom line

Most people with COVID-19 illness are contagious for about 10 days. People with severe illness or a weakened immune system can be contagious for longer. People who are fully vaccinated are contagious for short periods of time. If you’re contagious, you can pass the virus to other people.

It’s important to isolate yourself until you're not contagious anymore. The CDC Isolation and Exposure Calculator will tell you how long you need to isolate and when you should test for COVID-19 based on your symptoms and vaccine status.