How Long Are You Contagious with Covid-19? (2024)

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.

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.

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.

When is COVID-19 most contagious?

Are vaccinated people still contagious with COVID-19?

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.

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.

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.

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.

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.

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.

Sources:

• (2022).Covid-19 vaccine surveillance report: week 1. UK Health Security Agency.
  
• 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.
  
• Hakki, S., Zhou, J., Jonnerby, J., Singanayagam, A., Barnett, JL., Madon, KJ., Koycheva, A., Kelly, C., Houston, H., Nevin, S., Fenn, J., Kundu, R., Crone, MA., Pillay, TD., Ahmad, S., Derqui-Fernandez, N., Conibear, E., Freemont, PS., Taylor, GP., Ferguson, N., Zambon, M., Barclay, WS., Dunning, J., Lalvani, A. (2022). Onset and window of SARS-CoV-2 infectiousness and temporal correlation with symptom onset: a prospective, longitudinal, community cohort study. Lancet Respir Med.
  
• Preventing Spread of Respiratory Viruses When You’re Sick. CDC.
  
• Respiratory Virus Guidance. CDC.
  
• Riemersma, KK., Grogan, BE., Kita-Yarbro, A. (2021).Shedding of infection SARS-CoV-2 despite vaccination. Medrxiv.
  

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