With the COVID-19 pandemic still ongoing, one of the key questions people have is how long they may remain contagious after getting infected. Recently, the CDC updated their isolation guidance to state that people with COVID-19 should isolate for at least 5 days if they are not showing symptoms or their symptoms are resolving. However, this raises the question – are you still contagious with COVID-19 after 5 days?
Key Takeaways
- You are typically most contagious 1-2 days before symptoms start and for 2-3 days after
- After 5 days, you are much less likely to be contagious, but it is still possible
- Wearing a well-fitting mask for 5-10 days after ending isolation further reduces risk of spreading COVID-19
- Getting tested at the end of isolation with antigen test provides more information on whether you could still be contagious
- Those who were severely ill or are immunocompromised may need to isolate for longer than 5 days
Are you contagious after 5 days?
Although the risk is significantly lower after 5 days, it is still possible to be contagious with COVID-19 after a 5-day isolation. Studies have found that generally people are most contagious 1-2 days before their symptoms start and for 2-3 days after. However, with the highly transmissible Omicron variant, there is a higher viral load early on leading to potentially more contagiousness early in the course of illness.
After 5 full days of isolation, the viral load and risk of contagiousness decreases substantially in most people. One CDC study found that infected people were 66% less likely to be contagious after 5 days compared to 2 days. However, each individual infection differs, so some people may still be contagious past 5 days, which is why additional precautions are recommended.
Viral load and transmission risk over COVID-19 infection course
Studies that have measured viral load in infected people over time have found some key trends that demonstrate why 5 days is a turning point for contagiousness:
- Viral load generally peaks around the time of symptom onset or within the first 3 days of symptoms.
- After 5 days, viral load tends to be much lower and dropping.
- Viral culture studies show live virus drops significantly after 5 days.
- After 10 days, viable virus is almost never detected from respiratory samples.
So while viral load and contagiousness slowly taper off over time, the 5 day mark represents a point where infectiousness has substantially declined in most cases. However, experts emphasize there is no fixed timeline or cutoff, rather increasing evidence that transmission risk progressively declines each day beyond the peak.
What factors can prolong contagious period?
Although many people are past the point of highest contagiousness after 5 days of isolation, some factors can prolong the potential transmission window:
- Severity of illness – Those who had more severe COVID-19 are likely to remain contagious for longer than those with mild or moderate illness. Severe disease is associated with higher viral loads that take longer to clear.
- Immunocompromised status – People who are immunocompromised may shed virus for longer periods due to inability to mount a robust immune response.
- Lack of resolution of COVID-19 symptoms – Persistent symptoms like fever indicate ongoing viral replication.
- Being unvaccinated – Vaccines accelerate viral clearance from the body, so lack of vaccination enables longer persistence.
For people with these risk factors, a longer isolation beyond 5 days may be warranted. The CDC suggests consulting with your doctor in these cases.
Reducing transmission risk after ending isolation at 5 days
To account for the possibility of residual transmission after 5 days, the CDC recommends additional precautions following ending isolation to minimize infection risk:
- Wear a high-quality, well-fitting mask if around others at home and in public for an additional 5 days (day 6 through day 10).
- Avoid travel and situations where you would need to remove your mask such as dining out during this 5-day period.
- Avoid being around people who are at high-risk for severe illness unless you can mask consistently.
- Get tested with at least one negative antigen test before ending isolation, if possible.
Adhering to these mitigation measures for the 5 days after ending isolation reduces, but does not eliminate the possibility of ongoing transmission. But taken together, they substantially minimize the overall risk.
Does testing at the end of 5 days help?
The CDC suggests getting tested toward the end of your 5-day isolation if you have access to tests. This can provide additional information about whether you could still be contagious after your 5 days of isolation.
PCR tests can come back positive for weeks or longer after initial infection because they detect non-infectious viral remnants. So a PCR test isn’t helpful for determining the end of contagiousness.
However, antigen tests detect proteins from actively replicating live virus. Therefore, a negative antigen test result means virus levels are low and dropping. This supports that contagiousness is likely greatly diminished.
However, neither a negative test nor a 5-day isolation period guarantees you can no longer spread COVID-19. So it’s important to still mask around others until day 10.
When are you no longer contagious after COVID-19?
It’s difficult to provide a definitive timeline for no longer being contagious after COVID-19 infection. There is no firm cutoff where the risk suddenly drops to zero. Rather, contagiousness gradually declines over time as the viral load falls.
However, based on existing evidence, the following provides a general framework for COVID-19 contagiousness timeline:
- Most contagious: 1-2 days before symptom onset through 2-3 days after.
- Potentially contagious: For ~5 more days after the peak contagious period, but risk drops each day.
- Very unlikely to be contagious: 10 days after symptom onset, provided symptoms have improved.
- No longer contagious: Once all symptoms have fully resolved, unlikely to be able to transmit virus.
However, this timeline may vary based on individual factors and the predominant COVID-19 variant. Testing, masking, and isolating as long as possible reduce transmission risk to others.
How long should you isolate with COVID-19?
The recommended COVID-19 isolation period depends on your symptoms and test results:
- If no symptoms, isolate for at least 5 days after testing positive.
- If mild to moderate illness, isolate for 5 full days after symptom onset.
- If severe illness or immunocompromised, isolate for at least 10 days.
- End isolation after 5 or 10 days if fever-free for 24 hours without medication.
Regardless of duration, wear a high-quality mask around others at home and in public until 10 days after symptom onset or positive test. Avoid travel and high-risk settings during this time.
Precautions for households and close contacts
Household members and other close contacts who are not infected should also take precautions when someone they have been around tests positive or shows COVID-19 symptoms:
- Avoid contact with the infected person as much as possible.
- Wear a well-fitting mask if you must be in the same room indoors.
- Open windows and improve ventilation whenever possible.
- Don’t share household items like cups, towels and bedding.
- Clean high-touch surfaces regularly.
- Monitor yourself closely for COVID-19 symptoms daily.
- Get tested 3-5 days after last exposure or if symptoms develop.
Following public health recommendations including isolation, masking and testing remains crucial to controlling the COVID-19 pandemic and protecting vulnerable groups. Though risks decrease after 5 days, continuing precautions for 10 full days after infection provides an added buffer against ongoing transmission.
Conclusion
While risks substantially drop off after 5 days, it is still possible to spread COVID-19 for a period after a 5-day isolation. Wearing a high-quality mask around others, avoiding high-risk settings, and testing before ending isolation help reduce transmission risk. After 10 days with symptom improvement, transmission is very unlikely. However, each case differs, so it is important to follow isolation guidance closely, especially to protect high-risk groups.