London, Oct 04 : Covid-19 infection and vaccination have negligible effects on the severity of migraines, finds a study. People who perceived that their migraines worsened, those who had been infected were 2.5-times more likely to be concerned about migraine worsening. Patients who had been vaccinated were 17.3-times more likely to have this concern. The research, published in the 'European Journal of Neurology', was conducted among 550 adults who had received migraine-related care at a Spanish headache clinic. About 44.9 per cent (247) patients reported Covid at least once and 83.3 per cent (458) had been vaccinated; 24.7 per cent (61) reported their migraine worsening since contracting Covid and 11.4 per cent (52) since vaccination. When investigators examined patients' e-diary information, they observed no significant difference in headache frequency one month before and after infection or vaccination, even when comparing patients with and without self-reported migraine worsening. 'In the case of Covid-19, we reported previously that indeed headache is a frequent and disabling symptom of the infection; yet, it may not necessarily be linked to an increase in migraine frequency,' said the researchers from Vall d'Hebron University Hospital in Barcelona, Spain. 'In light of our results, we believe that clinicians should deliver to patients a more reassuring message that Covid-19 and Covid-19 vaccines may marginally affect migraine course and that probably the impact of the infection and vaccines is less than the individual rhythmicity to have attacks. This information may help minimise their worry,' the researchers said. /IANS