Danes know how vaccines work, but they underestimate how common mild side effects are

25 May 2021

A new population survey shows that Danes are generally well-informed when it comes to how COVID-19 vaccines prevent the disease. But almost half of Danes underestimate how many get mild, transient side effects, such as fever, after their COVID-19 vaccination.

Whereas the vast majority of Danes know what effect the COVID-19 vaccines have, many of them underestimate the occurrence of mild, transient side effects.

So concludes a new survey that looks into what Danes know about COVID-19 vaccines. The survey is conducted by the Danish Medicines Agency in collaboration with the research company Epinion. The results should be interpreted cautiously due to the fact that the survey was completed in the beginning of April when most had not yet been vaccinated and had not received the information describing these possible mild, transient side effects.

A key question put to the respondents was whether it is true of false that the risk of getting COVID-19 is smaller for vaccinated persons. Nine in ten said that the risk is smaller. The vast majority also believe that not as many vaccinated people as non-vaccinated people are admitted to hospital, and that the vaccines reduce the severity of the disease if you get COVID-19 despite being vaccinated. 

Many underestimate mild, transient side effects

However, the survey also shows that four in ten Danes greatly underestimate how often to expect mild transient side effects such as fever, headache and redness at the injection site after COVID-19 vaccination. 

Tanja Erichsen, Director of Pharmacovigilance at the Danish Medicines Agency, says:

“We know from the clinical trials conducted prior to approval of the vaccines that more than half of all vaccinated persons are expected to have mild, transient side effects such ad redness and tenderness at the injection site and headache. And up to one third, could develop feverish symptoms. So, people should be prepared for this.”

Fever is a natural immune system response

Tanja Erichsen adds that these mild side effects after vaccination are common and usually pass quite quickly.

“Feeling generally unwell, fever and aching muscles lasting for one to two days are natural reactions because the immune system is activated. This is no cause for alarm.”

We will now put these new insights into action by stepping up our information campaign – especially on social media. The aim is to tell people that it is completely normal to experience mild side effects after the COVID-19 vaccine and that they might feel unwell for a few days after vaccination.

The population survey will be repeated every three months until further notice.

Why we ask the Danes about COVID-19 vaccines

The population survey is intended to help members of the public, media, professionals and authorities to ensure that we all get the necessary information about the risk of COVID-19 and the vaccines’ efficacy and side effects, so that each person can make their own choice on an informed basis.  

Read the survey: ‘What Danes know about the efficacy and side effects of COVID-19 vaccines’