By the end of 2022, about one in four American adults is still an older teenager not infected with COVID-19according to new federal data.
The Centers for Disease Control and Prevention has been tracking seroprevalence – antibodies in the blood – by collecting national samples from blood donors between January and December 2022
Data shows 77.5% of those aged 16 and over have antibodies from COVID-19 infection by the time 2022 ends, according to the agency. final estimateup from the estimated 48.8% at the start of the year.
Meanwhile, if you include people who have antibodies either from infection, by being vaccinated or from a combination of both, the CDC estimates around 96.7% of the population.
When it came to age group, seniors aged 65 and over had the lowest estimated percentage of people with antibodies from a previous infection at 56.5% and youth and young adults aged 16 to 29 had the highest percentage at 87.1%.
Only 47 states and the District of Columbia have seroprevalence data, showing that Vermont has the lowest percentage of the estimated population with antibody-induced infection at 64.4% and Iowa has the highest percentage at 90.6%.
There was no major difference between men and women with 79.3% and 75.7%, respectively, thought to have antibodies from the infection.
Among racial/ethnic groups, Asian Americans had the lowest estimated percentage of infection-induced antibody at 66.1% and Hispanic Americans had the highest percentage at 80.6%.
“Despite the fact that the various variants of COVID are highly contagious, isn't it remarkable that, at the end of last year, only three-quarters – plus a few – of our population were infected and that may be a small but surprising,” Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center, told ABC News.
Experts say there are several reasons Americans may not have contracted COVID-19 including being more diligent about mitigating measures such as wearing masks and living in more rural areas.
“We have a large rural population in the United States, and maybe this virus hasn't reached everyone who lives in sparsely populated parts of the country,” said Schaffner. “Obviously, if you live in a big city where you meet people, there will be more opportunities for transmission.”
Experts add this is also a reminder of the importance of vaccination and it's not too late to get a shot for those who haven't already.
In April, the CDC and the Food and Drug Administration simplifies the vaccine schedule to recommend that everyone aged 6 years and over receive the updated bivalent COVID-19 vaccine, regardless of whether they have previously completed their monovalent primary course.
Additionally, the FDA's vaccine advisory committee recommended in June vaccine manufacturers updated their COVID booster shots to target XBB.1.5, which is the most common strain in the US
Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco, told ABC News that a simplified schedule is especially important as we approach the fall and cold weather, when cases usually tend to increase.
“It's not too late to keep an open mind about protection, especially since one in four is not a small number,” he said. “A lot of people have been exposed naturally but we know that (antibody) will decrease over time, and it's probably a good idea to get at least one recent shot… Simplification is the name of the game.”