Related Experiment Video
Updated: Jul 25, 2025

A Suction Blister Protocol to Study Human T-cell Recall Responses In Vivo
Published on: August 11, 2018
Immediate adverse reactions following COVID-19 vaccination among 16-65-year-old Danish citizens
K Torp Hansen1, F Kusk Povlsen2, B Hammer Bech1
1Department of Public Health, Aarhus University, DK-8000 Aarhus, Denmark.
Introduction:
There is sparse knowledge of immediate adverse reactions following COVID-19 vaccination.
Objective:
This study aimed to estimate the frequency and number of immediate adverse reactions following COVID-19 vaccination in a Danish population.
Methods:
The study used data from the Danish population-based cohort study BiCoVac. The frequencies of 20 self-reported adverse reactions were estimated for each vaccine dose stratified by sex, age, and vaccine type. Also, the distributions of number of adverse reactions following each dose were estimated stratified by sex, age, vaccine type, and prior COVID-19 infection.
Results:
A total of 889,503 citizens were invited and 171,008 (19 %) vaccinated individuals were included in the analysis. The most frequently reported adverse reaction following the first dose of COVID-19 vaccine was redness and/or pain at the injection site (20 %) while following the second and third dose, tiredness was the most frequently reported adverse reaction (22 % and 14 %, respectively). Individuals aged 26-35 years, females, and those with a prior COVID-19 infection were more likely to report adverse reactions compared with older individuals, males, and those with no prior COVID-19 infection, respectively. Following the first dose, individuals vaccinated with ChAdOx1-2 (AstraZeneca) reported more adverse reactions compared with individuals vaccinated with other vaccine types. Individuals vaccinated with mRNA-1273 (Moderna) reported more adverse reactions following the second and third dose compared with individuals vaccinated with BNT162b2 (Pfizer-BioNTech).
Conclusion:
The frequency of immediate adverse reactions was highest among females and younger persons, however, most of the Danish citizens did not experience immediate adverse reactions following COVID-19 vaccination.
More Related Videos
Related Concept Videos
Vaccinations
Pharmacovigilance
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
Allergic Drug Reactions
Hypersensitivities
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...
Allergic Reactions
Local Anesthetics: Adverse Effects
Once absorbed into the systemic circulation, local anesthetics can affect the organs that depend on the functioning of sodium...

