Two large studies have brought attention to potential health risks linked to the COVID vaccine, but experts have cautions that the findings should be interpreted carefully. The research suggests a possible link between vaccination and increased risks of acute kidney injury and certain respiratory infections.
The first study, published in the International Journal of Infectious Diseases, examined changes in infectious diseases before, during, and after the pandemic, as well as the impact of vaccines. Researchers found that while cases of influenza-like illness dropped during the early pandemic, upper respiratory infections and the common cold surged significantly in 2023 and 2024, well above historical levels. Lead author Dr. Jihun Song from the Department of Biomedical Informatics at the Korea University College of Medicine noted that pertussis (whooping cough) increased more than 40-fold compared to historical trends.
When the researchers analyzed the impact of the vaccine, they found that individuals who received four or more doses were less likely to contract influenza-like illnesses and whooping cough, but more likely to experience common colds and other mild respiratory infections. Dr. Song suggested that these mixed associations might reflect complex changes in immunity, behavior, and healthcare use in the post-pandemic era.
In another study published in the International Journal of Medical Sciences, researchers found a higher risk of acute kidney injury and dialysis within one year among vaccinated individuals. While the risk was statistically significant and well-controlled, the researchers acknowledged limitations, such as the lack of data on vaccine doses and antibody levels, and the potential for differences in healthcare use between vaccinated and unvaccinated groups to influence the results.
Experts have urged caution in interpreting the findings, noting that the studies are observational and cannot establish causation. Dr. Jacob Glanville, CEO of Centivax, emphasized the need to control for age and other confounding factors, pointing out that older vaccine recipients were more likely to be hospitalized for colds and respiratory infections, a factor that could skew the results. Dr. Hua Wang, an associate professor from the University of Illinois, also cautioned against overemphasizing the potential negative effects of the vaccine, highlighting the importance of considering all data points from both studies.
Dr. Marc Siegel, a Fox News senior medical analyst and author of the book The Miracles Among Us, acknowledged that the studies are large and raise important questions, but stressed that they do not prove causation. He noted that the findings should prompt further investigation into the long-term effects of the vaccines and the importance of carefully considering potential health impacts in the post-pandemic landscape.
Overall, the studies highlight the need to continue monitoring the long-term effects of the vaccines while recognizing the complex interplay of factors such as age, underlying health conditions, and changes in healthcare utilization that may influence the results. As the researchers and experts caution, the findings should not be interpreted as evidence that the vaccine increases or decreases specific infections but rather as indicators of population-level trends that require further investigation.