Navigating the constantly evolving COVID-19 landscape can be a challenge. This is especially true when it comes to understanding how long you're contagious for. With recommendations and guidelines frequently changing, it's easy to find yourself scratching your head. But fret not! We've put together a handy list of commonly-asked questions about COVID-19 infectiousness, along with MD-approved answers.

Currently under the weather? Exposed to someone with COVID-19? Just planning ahead? Our goal is to provide you with clear, helpful answers about contagiousness and isolation guidance. Let’s dive in.

What are the symptoms of COVID-19?

Symptoms of COVID-19 can vary quite a bit depending on the coronavirus variant and the individual. Mild symptoms include a runny nose, headache, fatigue, sore throat, loss of taste or smell, or GI issues like diarrhea. More severe symptoms include chest pain or shortness of breath.

These symptoms can overlap with illnesses like the common cold, RSV, and influenza. That’s why it's always best to consult with a healthcare provider if you're feeling under the weather - just to be safe.

Is COVID-19 contagious before symptoms show?

Yes, COVID-19 can be contagious before you experience symptoms. This means that infected individuals can spread it to others even if they aren't feeling sick yet. The period before symptoms appear is known as the pre-symptomatic phase. Since people can unknowingly be contagious, it’s important to practice good hygiene even if you feel healthy.

This is called asymptomatic spread, and it’s one of the reasons why COVID-19 has been challenging to control. It’s also why measures like frequent hand-washing and wearing high-quality masks if you’re feeling unwell are recommended.

When is COVID-19 most contagious?

COVID-19 is thought to be most contagious through day 5. This peak in infectiousness is largely due to viral shedding (when the virus in your body is released into the environment). The highest levels of viral shedding occur during and after symptom onset of congestion, fatigue, cough or a sore throat.

Are vaccinated people still contagious with COVID-19?

Yes. Even if you’re up-to-date on your COVID-19 vaccines, you're still capable of spreading COVID-19 to others. According to the Centers for Disease Control and Prevention (CDC), you should isolate from others regardless of vaccination status if you’ve tested positive.

Does being vaccinated make you less contagious?

According to the Coronavirus Research Center at Johns Hopkins, it isn’t 100% clear if the current COVID-19 vaccines make you less contagious. Some research indicates that vaccinated people are less likely to transmit COVID-19 than unvaccinated people.

However, several studies - including one sponsored by the CDC - have found little to no difference in the levels of viral load (the amount of virus in your body) in both vaccinated and unvaccinated people. In other words, the amount of virus was equal, regardless of vaccination status.

So why do some findings indicate that vaccinated people are less likely to transmit COVID-19? According to a report from the UK Health Security Agency (UKHSA), most studies indicate that COVID-19 vaccines prevent infection - and if you’re not infected, then you can’t transmit the virus to others. The sentiment is that you can’t spread the virus if you don’t get infected with COVID-19 in the first place.

How long are you contagious after you test positive for COVID-19?

After testing positive for COVID-19, the duration of contagiousness can vary. However, individuals are typically contagious for about 10 days after the onset of symptoms.

For those with mild to moderate symptoms, this period can be shorter, often around 5-7 days. For people with severe symptoms or those with a weakened immune system, contagiousness can last longer, potentially up to 20 days.

Are COVID-19 tests an effective way to indicate if you’re contagious?

Not exactly. PCR test and antigen test can detect the virus, but a positive test doesn't always indicate active contagiousness and a negative test doesn’t always indicate that you’re COVID-free.

It’s also worth noting that antigen tests are estimated to be accurate about 80% of time. PCR tests, which are estimated to be accurate about 95% of the time. In other words, COVID-19 tests aren’t always accurate in determining if you’re sick or not. Therefore, they’re also not always accurate in determining if you can spread the sickness to others.

In some cases, your test may be negative but your provider may suspect that your symptoms are related to COVID-19. In this event, they may order another test to confirm. You should continue to isolate in the meantime until the results come back.

It’s best to follow your healthcare provider's guidance and local public health recommendations for specific isolation periods.

When can you stop isolating for COVID-19?

The CDC states that you can end isolation if your symptoms have improved for at least 24 hours or if you’ve been fever-free for at least 24 hours without the use of fever-reducing medications.

It's also recommended that additional precautions, such as mask-wearing and avoiding close contact with others, are taken for another 5 days after ending isolation.

If symptoms return, you should start the protocol over again. Isolate until you’ve been fever-free for at least 24 hours, or until your symptoms have been improving for at least 24 hours. Afterwards, take additional precautions for an additional 5 days.

Recommendations for ending COVID-19 isolation

The recommendations for ending COVID-19 isolation involve a combination of time and symptom assessment. According to CDC guidance, individuals can stop isolating and return to work or school if they’ve been fever-free for 24 hours or if symptoms have been improving for at least 24 hours.

The CDC also recommends taking enhanced precautions to reduce contagiousness. These measures include opening windows to improve fresh air flow and masking around others for up to 5 days after ending isolation. This is especially important to protect those who are over 65 or have a weakened immune system.

It’s important to consult with a healthcare provider for personalized advice on isolation. This is because recommendations can vary based on your health conditions and local public health guidelines.

If you're experiencing COVID-19 symptoms or have tested positive, it's important to talk with your healthcare provider. Getting professional advice can make a significant difference in your recovery. It can also help prevent you from spreading the virus to others.

How Sesame Can Help

Looking for quick and accessible COVID-19 care? You can book an online COVID-19 screening to assess if your symptoms are related to COVID-19 and determine next steps.

If you’ve already tested positive, you can also book a telehealth visit for guidance on isolation and symptoms. Sesame’s clinicians can provide you with timely medical advice, treatment options and necessary support. This helps ensure that you receive the appropriate care while keeping your health and safety a priority.

Sources:

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• Auwaerter, P. (2023). Coronavirus COVID-19 (SARS-CoV-2). Johns Hopkins Medicine.
  
• Braeye, T., Catteau, L., Brondeel, R., van Loenhout, JAF., Proesmans, K., Cornelissen, L., Van Oyen, H., Stouten, V., Hubin, P., Billuart, M., Djiena, A., Mahieu, R., Hammami, N., Van Cauteren, D., Wyndham-Thomas, C. (2023). Vaccine effectiveness against transmission of alpha, delta and omicron SARS-COV-2-infection, Belgian contact tracing, 2021-2022. Vaccine.
  
• Chou, R., Dana, T., Jungbauer, R., Weeks, C. (2020). Update Alert 3: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings. Ann Intern Med.
  
• COVID-19 rebound after paxlovid treatment. CDC.
  
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• Preventing Spread of Respiratory Viruses When You’re Sick. CDC.
  
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• Riemersma, KK., Grogan, BE., Kita-Yarbro, A. (2021).Shedding of infection SARS-CoV-2 despite vaccination. Medrxiv.