Nearly 40 Percent Of CT Residents Had COVID-19: CDC Study

CONNECTICUT —Nearly 40 percent of Connecticut residents has been infected with COVID-19, according to the latest estimates from the Centers for Disease Control and Prevention.

The CDC estimates that almost 1.4 million Connecticut residents were infected by the end of January 2022, which is much higher than the 697,000 infections reported to health agencies.

Estimates are based on seroprevalence data, which looks for traces of infection-induced antibodies in blood samples. Blood samples come from commercial labs and were originally submitted for unrelated reasons such as routine checkups.

The CDC study provides more accurate data about the number of infections compared with offically-reported test results, said Dr. Richard Martinello, director of infection prevention for Yale New Haven Health. However, just because someone has antibodies doesn’t necessarily mean they are protected against re-infection.

Antibody levels tend to decrease over time, but more studies are needed to determine the relationship between antibody levels and the degree of protection, Martinello said. The immune system has other mechanisms, such as T-cells, to protect against re-infection as well.

Some coronavirus variants are more likely to re-infect people than others.

“We know people exposed to omicron, especially the BA.2 subvariant, can be re-infected,” Martinello said.

The best protection against a first infection or re-infection is to get vaccinated, he said. Growing evidence suggests that vaccination after infection produces a robust immune response.

“What I’m promoting is if someone has been infected and is not yet up to date on vaccinations, become up to date on vaccinations,” he said.

Connecticut’s estimated level of infection is lower than the national average, which is about 43 percent, according to the CDC.

The CDC study comes with some caveats. Blood samples weren’t chosen randomly and might not be representative of the entire U.S. population since it’s coming from people who received medical care.