At this stage in the pandemic, worrying that your sore throat, cough or congestion might, in fact, be COVID-19 is a natural thought, especially as .
But while testing negative on an at-home antigen test can bring some relief, unfortunately, you may no longer be able to trust that initial result in the way you could earlier in the pandemic.
Keep reading for what you need to know about COVID-19 incubation periods in 2024, why an early negative test could be a false result, and what to do if you鈥檙e caught in a 鈥淲ait, so do I have COVID or not?鈥� testing limbo.
It could take more time to test positive for COVID-19 than in years past
Some medical experts say they鈥檝e noticed that at this stage of the pandemic, it鈥檚 often taking much longer for people to get a positive test result on an at-home COVID-19 antigen test. In other words, they鈥檙e observing that people with COVID-19 symptoms are taking an antigen test and getting a negative result 鈥� only to get a positive result on a different test several days later.
This means that many people could wrongly assume they don鈥檛 have COVID-19 after that first negative test and then inadvertently spread the virus to friends and family.
Dr. Peter Chin-Hong, an infectious disease expert at UCSF, said he and his colleagues are now 鈥渟eeing people take longer to get a positive test鈥� even though they have COVID-19 symptoms. that she鈥檚 also noticed this delay 鈥� and that a patient might not get a positive test result up until the fourth day after the start of their symptoms.
But there鈥檚 a confusing additional aspect to this too: 鈥淧aradoxically,鈥� said Chin-Hong, incubation times for the virus have gotten shorter throughout the pandemic. This means people have tested positive for COVID-19 more quickly than in 2020, when the average incubation period was five days because the incubation period has changed with each new variant. Chin-Hong鈥檚 advice in the last year has been that if you鈥檙e having COVID-19 symptoms, it now makes sense to take a test as early as two days after exposure.
So how do shorter incubation times square with this newly observed delay on positive COVID-19 tests?
Your COVID-19 symptoms might be starting earlier
Right now, experts aren鈥檛 100% sure why antigen tests are taking longer to return a positive COVID-19 result. But Chin-Hong said that the hypothesis that makes sense to him is less about the efficacy of the antigen tests themselves and way more about how much quicker someone with COVID-19 might develop symptoms in 2024 than they would have done in 2020.
As a reminder, those symptoms are the sign that your body鈥檚 immune system is mounting a response to an invading virus 鈥� and back at the start of the pandemic, by the time you developed COVID-19 symptoms and took a test it would probably already be positive, Chin-Hong said.
But at this stage of the pandemic, most of us now have 鈥渁 lot of immune experience鈥� with COVID-19, Chin-Hong said 鈥� and the average person鈥檚 immune system is increasingly 鈥渙n guard鈥� and 鈥渁ctivated more than in 2020,鈥� he said. So when your body detects a burgeoning coronavirus infection now, 鈥測our whole immune system just gets agitated and active, and you begin to get sick sooner, but you actually don鈥檛 have as much virus in your blood yet,鈥� Chin-Hong said.
Dr. Abraar Karan, an infectious disease physician and researcher at Stanford University, also put it this way for NPR: 鈥淲ith our immune systems primed, when SARS-CoV-2 was a novel pathogen.鈥�
And because many of us take a COVID-19 test when we start to feel sick, we might be testing way too early at that time for an at-home antigen kit to successfully detect enough virus inside us. This mismatch between when your symptoms start and when you鈥檝e enough virus present in your body to result in a positive COVID-19 test 鈥渨as started to be observed in early omicron, but I think it just seems more accentuated now,鈥� Chin-Hong said.
However, Hudson of Kaiser Permanente Southern California told the L.A. Times that for her, this delay in positive tests over the years 鈥� either from getting infected or getting vaccinated.
The bottom line is: If you鈥檙e testing because you鈥檝e started feeling unwell, it鈥檚 unwise to assume in 2024 that a negative result automatically means you don鈥檛 have COVID-19, because you might just be testing too early.
So 鈥� what should I do if my first COVID-19 test is negative?
Experiencing the onset of symptoms that feel like COVID-19 is unpleasant and worrying enough. And now, this new possible delay around even knowing if you have COVID-19 adds another element of frustration and uncertainty to what鈥檚 already a stressful situation. Even if you鈥檝e been able to, one COVID-19 scare in a family can run through that stockpile pretty fast 鈥� and the cost of purchasing new COVID-19 antigen kits can really add up.
If you鈥檙e in the limbo of not knowing whether you actually have COVID-19 yet, here鈥檚 what to do:
If your first test is negative for COVID-19, test again later
If you have symptoms but have tested negative, don鈥檛 assume it means you鈥檙e COVID-free. and then test again after another 48 hours.
Chin-Hong advises that you can also , which is more sensitive.
While you鈥檙e unsure, play it safe
If you have symptoms and don鈥檛 know why yet for sure, stay home as much as you can. If you truly can鈥檛 stay indoors and away from others, wear a well-fitted mask to protect your community and
Be especially careful not to spread any virus around folks who are at higher risk for serious illness or hospitalization from COVID-19, which includes older people, immunocompromised and disabled people.
Remember: Just because it鈥檚 not COVID-19 doesn鈥檛 mean you鈥檙e not still sick
Even if you turn out not to have COVID-19 after several days of testing but you鈥檙e still experiencing symptoms, you might still be infected with one of And if you鈥檙e sick, you could easily infect your friends, family or colleagues with whatever you鈥檙e suffering from.
Give yourself permission not to trust a friend鈥檚 negative test, too
What if it鈥檚 a friend who鈥檚 experiencing COVID-19 symptoms, and they鈥檙e insisting that they鈥檙e safe to meet with you because 鈥渢hey took a test and it鈥檚 negative鈥�?
Knowing what you know 鈥� that it can sometimes take folks longer to get a positive COVID-19 test in 2024 鈥� you should feel free to compassionately tell your friend that while you trust them, you can鈥檛 trust an early negative test right now. There鈥檚 a good chance that they have no idea that positive tests can be increasingly delayed and will be relieved to know that by staying home, they haven鈥檛 accidentally spread an infectious disease to you or other loved ones.
And if they disagree and insist they鈥檙e still safe to meet up? You should feel free to decline, even if it feels awkward.
Stock up on free COVID-19 tests 鈥�
Finding a quick, free COVID-19 test 鈥� whether an at-home antigen test or a PCR test 鈥� has gotten progressively harder at this stage of the pandemic as more sites and services have shuttered. The federal government has, at least, restarted its through USPS, meaning you can once again order another four free antigen tests to be delivered to your door for a future time.
鈥� but make sure your COVID-19 tests haven鈥檛 expired
Many of the COVID-19 tests being made available right now () may be approaching their expiration date if they haven鈥檛 already passed it. And an expired test could give you an unreliable result.
to see by the manufacturer. The FDA said that if a test鈥檚 shelf life has been extended, it鈥檚 because the manufacturer has given the agency enough 鈥渄ata showing that the shelf-life is longer than was known when the test was first authorized.鈥� (In other words, it鈥檚 still OK to use that test.)
Copyright 2024 KQED