LIMA — The federal Centers for Disease Control (CDC) and Prevention estimates as many as 53% of Ohioans have previously been infected with coronavirus, according to the agency’s latest seroprevalence study.
The new estimates from the CDC are based on 72,000 blood samples taken in January to measure how many Americans have a detectable level of antibodies generated by a previous infection.
The data suggest as many as 140 million Americans, or 43% of the U.S. population has been infected with the virus since the pandemic started.
The CDC estimates as many as 6.2 million Ohioans have been infected through late January, far exceeding the 2.5 million confirmed cases reported by the Ohio Department of Health through Jan. 31.
The CDC regularly collects blood samples from commercial laboratories to update its estimates on the percentage of Americans who have been infected with the virus that causes COVID-19.
The estimates do not include people who have been vaccinated but have no history of infection, nor do the estimates measure the percentage of people with enough antibodies to protect from future infections, according to the CDC.
But a separate seroprevalence study based on national blood donor samples estimates that nearly 95% of Americans age 16 and older have generated antibodies through infection or vaccination as of December.
“The challenge we’ve got to figure out is to what extent do people develop large quantities of antibodies, and to what extent does that infection give them immunity against (coronavirus variants) that are out there right now,” said Steven Martin, professor and dean of the Ohio Northern University College of Pharmacy.
While antibodies generated by infection and vaccination wane, leaving people vulnerable to reinfection or developing a breakthrough infection, both infection and vaccination can generate cellular immunity to fight off an infection once it starts.
But adding vaccination after someone has recovered from COVID-19 “makes the immunity stronger against a wider variety of variants,” Martin said. “That’s why we continue to recommend people get vaccinated if they’ve had COVID.”
“Getting infected is playing a dangerous game where you can be at risk for severe outcomes from COVID,” said Brandon Fischer, Allen County health commissioner.
A lot of people are suffering from long COVID, or symptoms that persist for months, while those who have previously been infected with the virus are also at higher risk for developing heart issues, Fischer said. “So it’s best to use the vaccine to prevent infection rather than try to let them catch the disease and have potential secondary and tertiary outcomes from infection from COVID-19.
“We just don’t see those types of issues with the vaccine.”
