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The U.S. is currently in the midst of a Covid wave, fueled by the JN.1 variant that\u2019s driving up hospitalizations and deaths across the country. For most people, however, the new variant doesn\u2019t seem to be causing worse symptoms.<\/p>\n
That\u2019s left many wondering whether we need to keep swabbing our nasal passages with Covid tests at the first sign of congestion or achiness? How well do at-home rapid tests work against the new variant?<\/p>\n
Here\u2019s what to know:<\/p>\n
Influenza and some cold viruses are circulating along with Covid. So there are good reasons to know which virus you\u2019ve got, particularly if you are at higher risk of getting really sick.<\/p>\n
\u201cIt\u2019s important to know if you have Covid versus the flu versus something that\u2019s not viral at all \u2014 like strep throat \u2014 because they have different treatments,\u201d said Dr. Abraar Karan, an infectious disease physician at Stanford Medicine. \u201cThey have different treatments, and the sooner you get treated the better outcome you\u2019ll have.\u201d<\/p>\n
For a healthy 25-year-old, there is still some utility in getting tested. If somebody in the home has a weak immune system or is fighting cancer, for example, it\u2019s important to isolate if it\u2019s Covid.<\/p>\n
\u201cRemember for all these viruses or bacterial infections, contagiousness is different and how sick you may get is different.\u201d Karan said.<\/p>\n
Joseph Petrosino, a chair of molecular biology and microbiology at Baylor College of Medicine, acknowledged that while it may not be as necessary\u00a0for young, healthy people to take an at-home test, it can be helpful to know if it\u2019s Covid in case someone ends up with lingering symptoms.<\/p>\n
\u201cThere are healthy people, runners or people who work out, who do get long Covid as well,\u201d he said. \u201cYou just really never know \u2014 it\u2019s hard to predict just based on comorbidity factors alone.\u201d<\/p>\n
Otherwise, for someone who is low-risk, getting a positive Covid test won\u2019t change much about treatment. Whether it\u2019s Covid, a cold or flu, get plenty of rest, hydration and stay away from others.<\/p>\n
There is no data that the JN.1 variant should have any effect on the results of an at-home rapid test, experts say.<\/p>\n
\u201cI have not seen anything to suggest that the newer variants have evaded detection on tests,\u201d said Karan. \u201cCertainly this has happened in the past with other diagnostics earlier in the pandemic, but at this point the tests should pick up these variants.\u201d<\/p>\n
Susan Butler-Wu, a clinical pathologist at Keck School of Medicine at the University of Southern California, said that while she hasn\u2019t seen data for this specific variant, if it\u2019s anything like other variants, it won\u2019t be an issue.\u00a0Rapid tests actually look for a part of the virus that is less likely to mutate and dodge the tests.<\/p>\n
\u201cThere\u2019s always this fear that we\u2019re going to have some mutation that\u2019s now going to make the tests not work, but so far that\u2019s not really the case,\u201d said Butler-Wu.<\/p>\n
In the early days of the pandemic, before most people had some kind of immunity either after infection or from the vaccines, an individual\u2019s viral load would be highest when symptoms first appeared.<\/p>\n
Now, the levels of virus may actually be highest a few days into the illness, according to a study published last fall in the journal Clinical Infectious Diseases from researchers at Harvard Medical School. They found that in those with pre-existing immunity, the level of virus peaks around the fourth day of symptoms.<\/p>\n
This means that if someone tests too early in the illness, it may show up negative.<\/p>\n
\u201cTheir symptoms could be caused by their immune response,\u201d Karan said. \u201cSo you\u2019re getting some inflammation and that\u2019s causing symptoms, and that\u2019s also preventing the virus from building up quite as fast, and so your initial test could be negative.\u201d<\/p>\n
The Centers for Disease Control and Prevention still recommends testing immediately if you believe you\u2019ve been exposed to Covid and are showing symptoms such as congestion, cough or body aches.<\/p>\n
If you\u2019ve been exposed but don\u2019t have any symptoms, the CDC says to wait five days.<\/p>\n
There is a misconception that rapid tests are \u201cone and done,\u201d says Butler-Wu.<\/p>\n
\u201cIf you\u2019re symptomatic and the first one is negative, you need to repeat it,\u201d she said.<\/p>\n
The official guidance from the CDC is that if you have symptoms, take a rapid test, and if it\u2019s negative repeat it 48 hours later.<\/p>\n
At-home rapid tests are a good way to know if someone is contagious.<\/p>\n
Simply put, rapid tests require a higher level of virus to turn positive, and higher levels of virus typically mean somebody is more contagious.<\/p>\n
There are some limitations to the tests, however.<\/p>\n
Karan said that while early on in the course of the illness they can be good proxies for contagiousness, they aren\u2019t as reliable at the end of an illness.<\/p>\n
There is data where rapid tests were positive, but when they got people\u2019s samples, the virus couldn’t be cultured \u2014 meaning that those people were unlikely to be contagious, Karan said. <\/p>\n
A 2022 study from researchers at Harvard Medical School suggested that only half of people who test positive after five days are actually contagious.<\/p>\n
\u201cAfter that time period, if your rapid test is positive it\u2019s not a guarantee you\u2019re still contagious.\u201d<\/p>\n<\/div>\n