Almost 6 in 10 Americans have signs of previous COVID-19 infection, showing the widespread reach of the virus, according to new data released by the Centers for Disease Control and Prevention.
The CDC study shows that the percentage of people testing positive for antibodies — an indication of previous COVID-19 infection — increased from about 34 percent in December to about 58 percent in February.
That period of a sharp increase coincides with the surge in cases from the omicron variant. But the antibody testing shows that even more people than reported have been infected, as has long been estimated, given that not all cases are detected or reported.
One CDC official said a forthcoming estimate will show that at some points there were as many as three total COVID-19 infections for each case that was reported.
CDC officials stressed that having previously been infected does not necessarily mean that someone is protected going forward, given that immunity can wane over time. Vaccination also provides additional protection when added to immunity from infection.
Therefore, health officials say that all eligible people should get vaccinated and boosted even if they have previously had the virus.
The breadth of previous infection does provide some additional layer of protection across the population, though, that experts say can help blunt the effects of the current uptick in cases.
The rate of previous infection was even higher among children, at 75 percent among those age 11 years and under. The level was much lower, around 33 percent, among those over 65.
“These findings illustrate a high infection rate for the Omicron variant, especially among children,” the study states. “[Testing positive for antibodies] should not be interpreted as protection from future infection. Vaccination remains the safest strategy for preventing complications from [COVID-19] infection, including hospitalization among children and adults.”
