An alarming amount of vaccine-hesitant people who list side effects as a top concern falsely believe the vaccines cause death, DNA alteration, infertility or birth defects, according to recent Harris polling. Why it matters: Respondents also listed blood clots, which are a real side effect of some coronavirus vaccines, but extremely rare. This survey suggests that misinformation or a skewed understanding of risk may be behind a sizable portion of vaccine hesitancy. Between the lines: The survey drilled down into the concerns of respondents who said they are "not likely" to get a vaccine, specifically the 25% who cited being worried about side effects as one of their top reasons for not getting vaccinated.