Headache following vaccination against COVID-19 among healthcare workers with a history of COVID-19 infection: a cross-sectional study in Iran with a meta-analytic review of the literature

BACKGROUND: There is evidence of the occurrence of headache after vaccination against COVID-19. However, only a few studies have examined the headache characteristics and related determinants, especially among healthcare workers with a history of COVID-19 infection. METHODS: We evaluated the incidence of headaches after injection of different types of COVID-19 vaccine to determine factors relating to the incidence of headache after vaccination among the Iranian healthcare workers who had previously contracted COVID-19. A group of 334 healthcare workers with a history of COVID-19 infection were included and vaccinated (at least one month after recovery without any COVID-19 related symptoms) with different COVID-19 vaccines. The baseline information, headache characteristics and vaccine specifications were recorded. RESULTS: Overall, 39.2% reported experiencing a post-vaccination headache. Of those with a previous history of headache, 51.1% reported migraine-type, 27.4% tension-type and 21.5% other types. The mean time between vaccination and headache appearance was 26.78 ± 6.93 h, with the headache appearing less than 24 h after vaccination in most patients (83.2%). The headaches reached its peak within 8.62 ± 2.41 h. Most patients reported a compression-type headache. The prevalence of post-vaccination headaches was significantly different according to the type of vaccine used. The highest rates were reported for AstraZeneca, followed by Sputnik V. In regression analysis, the vaccine brand, female gender and initial COVID-19 severity were the main determinants for predicting post-vaccination headache. CONCLUSION: Participants commonly experienced a headache following vaccination against COVID-19. Our study results indicated that this was slightly more common in females and in those with a history of severe COVID-19 infection.