Had COVID at Christmas? You could get it again now

As a stealth wave of COVID-19 makes its way across the U.S., those who have so far evaded the virus are now falling ill — while others are catching COVID-19 for a second, third or even fourth time.

Several factors have conspired to make the state of the pandemic harder than ever to track. The rise of at-home tests, which rarely make it into official case numbers, have made keeping accurate count of positive cases impossible. Additionally, many U.S. states and jurisdictions are now reporting COVID-19 data only sporadically to the Centers for Disease Control and Prevention. Earlier this week, Washington, D.C., reported case data to the agency for the first time since April.

This has happened just as new, more contagious subvariants of omicron are making their way through the U.S. population, leading not only to rising first-time COVID-19 cases but also frequent reinfections.

The latest versions of the virus appear particularly adept at evading the body’s immune response from both past COVID-19 infections and vaccines. Studies suggest most reinfection cases aren’t even being reported, giving little insight into how often they occur.