With the surge in COVID cases during the winter, health professionals are observing a delayed detection period for infections. Initially, when COVID-19 antigen tests, commonly referred to as rapid tests, were introduced, individuals would typically test positive within one to two days after the onset of symptoms. However, experts are now noting that it can take up to four days after symptoms appear for a positive test result.

“People’s immunity is improving over time,” explained Dr. Peter Chin-Hong, an infectious disease expert at the University of California San Francisco. This enhanced immunity stems from vaccinations or previous infections, meaning even a small amount of virus can be swiftly tackled by activated immune cells.

However, a challenge arises when individuals who initially test negative fail to retest, potentially unknowingly spreading the virus. Chin-Hong emphasizes the importance of continued caution around others. He suggests wearing a mask for 48 hours after an initial negative test or taking another test. For those seeking certainty, he recommends an initial PCR test. In cases of doubt, additional rapid tests or consulting a doctor for a PCR test, especially for those at high risk considering Paxlovid prescription for symptom treatment.

Chin-Hong notes the importance of obtaining Paxlovid within the first five days, and he expresses confidence that most individuals today, given their immune cell repertoire, should test positive within this timeframe.

This concern arises amid the emergence of a more contagious subvariant, JN.1, potentially contributing to the recent surge in COVID cases. Several California counties, including Alameda and Contra Costa Counties, have entered the Center for Disease Control and Prevention’s Medium Level for COVID hospitalizations.