Around 98 percent of COVID-19 reinfections are occurring in patients previously infected with the virus more than 90 days ago, suggesting that waning immunity — rather than highly transmissible variants — is propelling the uptick, according to Helix, a lab that helps the CDC with viral surveillance.
Epidemiologists and infectious disease experts have been closely monitoring trends in reinfections as the BA.5 variant dominates current cases.
Peter Chin-Hong, MD, an infectious disease specialist and professor of medicine at the University of California San Francisco, told The Wall Street Journal that the 90-day reinfection standard is "completely out the window" due to BA.5's ability to reinfect. However, data from Helix shows the average time between infections increased from 230 days in April to 270 days in July.
The latest surveillance from the lab, collected from July 31 to Aug. 7, further supports the notion that reinfections are linked to waning immunity. "New data reinforces our earlier conclusion that while reinfections are rising rapidly, ones that occur within 90 days of the original infection are rare," Helix said in an email to Becker's.