Systemic side effects after receiving a COVID-19 vaccine jab, such as nausea, fever and fatigue, are correlated with higher antibodies, according to a study published Oct. 21 in a JAMA Network Open research letter.
Among the 928 study participants who reported their post-vaccination symptoms, had received at least two vaccine shots and submitted a dried blood spot, "systemic symptoms were associated with greater antibody response," the researchers wrote.
After either COVID-19 vaccine dose, 12 percent of study participants reported local symptoms, which includes temporary reactions such as injection site pain, while 48 percent self-reported systemic side effects.
Women, younger age groups and patients who received a Moderna vaccine were associated with a better antibody response, but factors such as race, BMI and underlying conditions were not. Because of this variability, and because the average age was 65 and most of the participants werewhite, the researchers concluded more research between symptoms and vaccine effectiveness is required.