Although being up to date with your COVID-19 vaccinations does help reduce the risk of infection, it’s still important to get tested even if you don’t develop symptoms. Here’s what you should do if you were recently exposed to COVID-19.
How Long Should You Wait Before Getting Tested?
According to the Centers for Disease Control and Prevention (CDC), individuals who’ve had close contact with someone who has COVID-19 should get tested at least five days after exposure. While waiting to get tested, go into quarantine and don’t travel anywhere.
If you’re experiencing COVID-19 symptoms, get tested right away.
“You can do a rapid or polymerase chain reaction (PCR) before this period if you have symptoms,” LaTasha Perkins, MD, a family physician at MedStar Georgetown University Hospital, told Verywell. “And you can trust that it is positive if it’s positive before three to five days. It’s the false negatives we are trying to avoid.”
A COVID-19 test result represents whether the sample contains enough of the virus’s genetic material at the particular moment of testing to show a positive result or not. Because the virus takes time to build up in the system, testing earlier than recommended may result in a false negative.
“If [you’ve tested] within three days of the exposure, a negative result should be viewed with caution because you still might come up positive over the next few days,” Andy Pekosz, PhD, virologist at the Johns Hopkins Bloomberg School of Public Health, told Verywell.
The incubation period of SARS-CoV-2—the amount of time between infection and symptom onset—can take up to 14 days. That’s why the CDC recommends screening for COVID-19 weekly if you’ve been exposed. The average incubation period for Omicron, however, is estimated to be two to four days, which is shorter than earlier variants.
“We assume that BA.2.12.1 is similar to other Omicron variants, but there isn’t any good data specific to this subvariant that I’m aware of,” Pekosz said.
Does the Type of Test Matter?
There are two main types of COVID-19 diagnostic tests: antigen tests and molecular tests. The PCR test, a type of molecular test, is generally more sensitive and more accurate than rapid antigen tests.
The PCR test can turn positive faster than the rapid antigen test because it is designed to detect even small amounts of virus, Pekosz said. However, it may be better to wait out the recommended five days before testing.
“PCR [tests] are going to be more accurate regardless of time, but waiting increases its accuracy,” Perkins said. “If you wait, one test should suffice, unless you develop symptoms or are later exposed.”
Symptomatic people who test negative with an antigen test should confirm the result with a PCR test because it might be a false negative.
Some COVID-19 at-home test kits come with two tests inside. That allows people to take both tests a few days apart to increase the chances of an accurate result. According to a 2021 study published in The Journal of Infectious Diseases, all testing types are more than 98% sensitive in detecting a COVID-19 infection if used at least every 3 days.
“It takes a couple of days for the virus to replicate enough to be detected by a COVID-19 test, so it’s good to test a few times after a known exposure,” Pekosz said.
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.
