CDC Report Reveals Promising Data on COVID-19 Immunity Among Americans.

A CDC report published on June 2 in the Morbidity and Mortality Weekly Report (MMWR) found that approximately 96% of Americans over the age of 16 have some immunity to COVID. The study's data was collected between June and September 2022 and found that 26% of people had immunity from COVID vaccination, while another 22% had immunity from COVID infection alone. Nearly 48% had hybrid immunity, from both vaccines and a prior infection.

Commander Jefferson Jones, MD, MPH, USPHS, the report's author and a medical officer with the CDC’s Coronavirus and Other Respiratory Viruses Division, stated, "This likely has contributed to the decreasing level of hospitalizations and severe disease that we've seen."

The report also shed light on the different types of immunity, and where Americans' antibodies are coming from. Hybrid immunity, which is antibodies from a vaccine and a prior infection, is considered the strongest. But a person is still protected if they have antibodies from just a prior infection or just a COVID vaccine, although vaccine-induced immunity is preferred by many medical professionals. Immunity—regardless of whether it's from an infection or a vaccine—wanes over time, making it challenging to quantify the degree of COVID protection that exists in the United States.

"Once you're infected, the test we use can detect antibodies for at least a year and potentially several years," clarified Dr. Jones. "The presence of an antibody doesn't necessarily mean you can't get infected or you can't get severe disease."

It's important to remember that having antibodies does not completely protect a person from COVID. While the MMWR report found that nearly 86% of the unvaccinated had infection-induced immunity as compared to 64% of vaccinated people, those who were unvaccinated were also more likely to get a new COVID infection.

The report's findings provide more insight into the effectiveness of vaccination programs throughout the pandemic. People over age 65 had the lowest rate of hybrid immunity and similarly low levels of infection-related immunity, reflecting a success in public health and other efforts to prevent infection in this age group, according to Dr. Jones.

He added that the number of people who are highly protected really depends on transmission rates and on how many people stay up to date on their vaccines.

The strength of this immunity may vary, but at the very least, almost all people have some experience fighting off the virus, meaning they’ll be less likely to get severely sick as a result.

“The overwhelming amount of immunity in the population tells us we need to be much less concerned about serious disease and overwhelming hospitals,” said Dr. Klausner. “While we can continue monitoring, we would not anticipate the major disruptions that occurred in society [in 2020].”

But on the more individual level, it can be challenging to figure out how strong each person’s immunity really is.

There are antibody tests, but they’re not yet available over the counter, Dr. Jones said. People can test at local clinics to see if they have antibodies, or can get more detailed information from tests done with an infectious disease expert, Dr. Klausner added.

But the best thing people can do to make sure they have solid immunity is simply to stay up to date on COVID vaccines, experts agreed.

Everyone ages 6 and older is considered up to date on their COVID shots once they've received one dose of the updated bivalent booster, but people who are older than 65 or who are immunocompromised can get additional doses. So far, only 17% of the U.S. population has met this metric.

“When people get their flu shot, they can also get a regular COVID shot once a year,” Dr. Klausner encouraged. “That will help boost and maintain their antibodies.”

Eventually, we may see more universal COVID shots that protect against all COVID variants, but we’re not there yet, Dr. Klausner noted. Until then, scientists will keep updating COVID shots, likely annually, to keep people safe from whichever variants are most prominent at the time.

“The most important thing you can do is stay up to date on your vaccination,” Dr. Jones confirmed. “It’s the safest way to protect yourself against severe illness.”