Some posts on social media are claiming a South Korean study shows COVID-19 vaccines “weaken the immune system”. That’s misleading, and the study’s authors say so themselves. science.feedback.org/review/south...

Science Feedback spoke to Dr. Jihun Song, the first author. Dr. Song stressed that the study was “an observational analysis of associations” and “cannot make causal claims about immune function”.

We also consulted Prof. Helen Petousis-Harris, who highlighted major limitations. Yes, the study found more common colds in people with 4+ doses, but that same group had lower rates of flu-like illness and pertussis. That pattern doesn’t fit the claim of “weakened immunity”.