ATLANTA — New research from the U.S. Centers for Disease Control and Prevention found that a person gets stronger immunity against COVID-19 by getting one of the approved vaccines than if they develop "natural' immunity by catching the virus.
The research found fully vaccinated people and those previously infected with SARS-CoV-2 each have a low risk of subsequent infection for at least 6 months.
The CDC wrote:
"The immunity provided by vaccine and prior infection are both high but not complete (i.e., not 100%). The body of evidence for infection-induced immunity is more limited than that for vaccine-induced immunity in terms of the quality of evidence."
The agency and public health experts say there is not enough data to determine an antibody titer threshold, which indicates when an individual is protected from infection. Antibody titer is a laboratory test that measures the level of antibodies in a blood sample.
At this time, there is no FDA-authorized or approved test to reliably determine whether a person is protected from infection.
The research found that completing a primary vaccine series, such as one shot of Johnson & Johnson's viral vector vaccine, or two shots of either Pfizer or Moderna's mRNA vaccines, typically leads to a more consistent and higher-titer initial antibody response. This was especially true in the mRNA vaccines.
"Substantial immunologic evidence and a growing body of epidemiologic evidence indicate that vaccination after infection significantly enhances protection and further reduces risk of reinfection, which lays the foundation for CDC recommendations," the CDC wrote.
The CDC added that it needs to do more research in this area.