Abstract
In mRNA COVID-19 vaccination, side effects after the first and second dose have been well reported. However, studies about side effects after booster vaccine are sparse. 272 healthcare workers who received the third mRNA COVID-19 vaccine were recruited, and impact of sex, age, and symptoms on the side effect progression was statistically analyzed. Females and younger adults had a higher frequencies of general fatigue, headache, joint pain, chills and axillary pain compared to males and elderly adults, respectively. In longitudinal analysis, prolonged time to recovery from side effects was found among females and younger adults. Finally, between the third and second dose vaccinations, 52% of subjects had a longer duration of side effects following the third vaccine compared to the second, and joint pain was the culprit symptom related to the prolonged duration of side effects. Following the second vaccine dose, 25% of subjects had a longer duration of side effects and asthma and ear fullness, which exacerbated the underlying allergic condition, and COVID arm symptom were the culprit symptoms. These highlight the impact of sex, age, and culprit symptoms on the progress of side effects following the booster mRNA COVID-19 vaccine.