If you’ve been vaccinated, the best time to get tested is three to five days after an exposure. If you aren’t fully vaccinated, quarantine right away.

Published: September 10, 2021 | Updated: December 2, 2023

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It can take almost a week after exposure to COVID-19 to have a positive test result.

If you are fully vaccinated, you should wait three to five days after exposure before getting a test. Evidence suggests that testing tends to be less accurate within three days of exposure. Wear a mask in public indoor settings for 14 days or until you get a negative test result.

If you aren’t fully vaccinated, quarantine right away after you’ve been exposed to someone with COVID-19. If you develop symptoms, get tested right away. Otherwise, wait five to seven days.

COVID-19’s incubation period lasts up to 14 days. If you have the virus, it takes time to build up in your system. Early testing can result in samples that don’t contain enough of the virus’ genetic material to show a positive result. A COVID-19 test is limited in that it represents only a snapshot in time. A negative PCR test for COVID-19 does not mean that an individual is free of infection, but rather that, at that particular moment, the sample did not contain viral levels at a high enough concentration to be measured as a positive.

“If you aren’t vaccinated, it’s important to quarantine to limit the spread of the virus if you were within 6 feet of someone who has COVID-19 for a total of 15 minutes or more,” said Steven Patton, D.O., family medicine physician at Norton Community Medical Associates – Preston. “The length of time spent with the person is irrelevant if you hugged or kissed, shared utensils or a drink, or were on the receiving end of a sneeze or cough.”

If you aren’t fully vaccinated, isolate yourself at home while awaiting test results even if you don’t have symptoms. Follow CDC guidelines for quarantine and isolation.

While in quarantine, watch for a fever, shortness of breath or other COVID-19 symptoms. Those who are experiencing severe or life-threatening symptoms should seek emergency care immediately.