# Clinical characteristics of headache after vaccination against COVID-19 (coronavirus SARS-CoV-2) with the BNT162b2 mRNA vaccine: a multicentre observational cohort study

## TL;DR

This study examines the clinical features of headaches following the BNT162b2 mRNA vaccine for COVID-19, revealing specific patterns and symptoms.

## Contribution

The study provides the first detailed description of the clinical characteristics of post-vaccination headaches with the BNT162b2 mRNA vaccine.

## Key findings

- Headaches typically occur 18 hours post-vaccination and last about 14 hours.
- Most headaches are unilateral, with common symptoms including fatigue and muscle pain.
- Only 9.7% of participants reported similar headaches from previous vaccinations.

## Abstract

The novel coronavirus SARS-CoV-2 causes the infectious disease Covid-19. Newly developed mRNA vaccines can prevent the spread of the virus. Headache is the most common neurological symptom in over 50% of those vaccinated. Detailed information about the clinical characteristics of this form of headache has not yet been described. The aim of the study is to examine in detail the clinical characteristics of headaches occurring after vaccination against Covid-19 with the BNT162b2 mRNA Covid-19 vaccine for the first time.

In a multicenter observational cohort study data on the clinical features and corresponding variables were recorded using a standardized online questionnaire. The questionnaire was circulated to 12,000 residential care homes of the elderly as well as tertiary university hospitals in Germany and the United Arab Emirates. The primary outcomes of this study are the clinical features of headache after vaccination. Comorbidities, treatment with medication and sociodemographic variables are also analyzed.

A total of 2349 participants reported headaches after vaccination with the BNT162b2 mRNA Covid-19 vaccine. Headaches occur an average of 18.0 ± 27.0 hours after vaccination and last an average duration of 14.2 ± 21.3 hours. Only 9.7% of those affected also report headaches resulting from previous vaccinations. In 66.6% of the participants headache occurs as a single episode. A bilateral location is indicated by 73.1% of the participants. This is most often found on the forehead (38.0%) and temples (32.1%). A pressing pain character is indicated by 49.2% and 40.7% report a dull pain character. The pain intensity is most often moderate (46.2%), severe (32.1%) or very severe (8.2%). The most common accompanying symptoms are fatigue (38.8%), exhaustion (25.7%) and muscle pain (23.4%).

Headaches after Covid-19 vaccination show an extensive complex of symptoms. The constellation of accompanying symptoms together with the temporal and spatial headache characteristics delimit a distinctive headache phenotype.

Graphical Abstract