Study Finds People ‘Up To Date’ with COVID-19 Vaccines More Likely to be Infected
A new study conducted by researchers at the Cleveland Clinic in Ohio has found that individuals who are “up to date” with their COVID-19 vaccinations are actually more likely to become infected. This surprising discovery challenges the assumption that being fully vaccinated provides strong protection against the virus.
The study, which was published on the medRxiv server on June 12, analyzed data from 48,344 employees of the Cleveland Clinic. The researchers found that vaccinated individuals who received one of the updated bivalent vaccines had a higher risk of infection compared to both vaccinated and unvaccinated individuals. This increased risk persisted even after accounting for factors such as age and job location.
The researchers did not provide specific vaccine effectiveness estimates, as they did not calculate the number of infected employees who were unvaccinated. However, it is worth noting that 87 percent of the clinic’s employees had received at least one dose of a vaccine.
One possible explanation for the higher risk of infection among vaccinated individuals is the decreased effectiveness of the bivalent vaccines against new variants, such as the XBB lineages. The researchers also pointed out that the Centers for Disease Control and Prevention (CDC) does not formally recognize the protection provided by prior COVID-19 infection in its vaccination guidance.
The study’s findings have raised questions about the CDC’s definition of being “up to date” with vaccinations. The definition has changed multiple times during the pandemic, and currently, it means having received all recommended vaccine doses. However, the researchers found that meeting this definition did not necessarily result in better protection against infection.
The Cleveland Clinic researchers also examined the protective effect of natural immunity. They discovered that individuals who were infected by a recent Omicron subvariant had a higher level of protection compared to those infected by earlier subvariants or pre-Omicron strains. However, the study did not provide estimates of natural immunity’s effectiveness against severe disease.
These findings have significant implications for public health officials and individuals making decisions about vaccination. While the CDC maintains that COVID-19 vaccines are effective at preventing severe illness and death, this study suggests that the bivalent vaccines may not offer robust protection against certain variants, such as the XBB lineages of the Omicron variant.
It is important to note that the study has not yet undergone peer review, and further research is needed to confirm these findings. However, the study highlights the need for ongoing evaluation of vaccine effectiveness and the consideration of natural immunity in vaccination strategies.
