"COVID-19 Vaccine, Post-Vaccination Side Effect Prevention Less Effective Than Expected" [Reading Science]

US Department of Veterans Affairs St. Louis Hospital Research Team Publishes Paper in Nature Medicine

[Asia Economy Reporter Kim Bong-su] A large-scale study in the United States has found that COVID-19 vaccines are less effective than expected in preventing aftereffects, known as long COVID.

A research team from the St. Louis Hospital under the U.S. Department of Veterans Affairs published a paper with these findings in the international journal Nature Medicine on the 25th. The team conducted a comparative study from January to December last year involving over 34,000 breakthrough COVID-19 infection patients, about 113,000 unvaccinated infected individuals, and 13 million uninfected people. The results showed that the vaccine's effectiveness in preventing aftereffects was only about 15%.

This figure contrasts with previous smaller studies that mostly reported high preventive effects. Additionally, a study analyzing health records self-reported by 1.2 million healthcare app users in the United Kingdom found that the second vaccine dose reduced the risk of long COVID by half. However, in this study, when investigating people six months after COVID-19 diagnosis, symptoms such as dizziness (brain fog) and fatigue appeared to have little relation to vaccination status.

Experts view these findings as data emphasizing the importance of preventive measures such as mandatory mask-wearing and social distancing. They argue that relying solely on vaccines is insufficient and that auxiliary preventive measures like mask-wearing and social distancing must be consistently maintained. Some have countered that data after the emergence of the Omicron variant should be added and that the study results are based solely on simple statistics without considering patients' medical histories.

Professor Steven Dix of the University of California stated, "These findings show the need for more research on long COVID and the promotion of developing treatments and therapeutics," adding, "Even now, doctors worldwide only have questions and know nothing about the definition of long COVID, biomarkers, imaging tests, or treatments."