Comparison of Covid-19 symptoms vs. vaccine side effects

Reactions and side effects have played a huge role in discussions since the first SARS-CoV-2 vaccines were developed. But how are we meant to classify the overload of information and headlines? What about the proportionality of the risks of getting seriously ill with Covid-19 on the one hand and suffering side effects stemming from the vaccinations on the other?A complete picture is only made possible through comparing the vaccine reactions and side effects side-by-side with the symptoms of Covid-19 disease. The choice between getting vaccinated or not is about a risk / harm-benefit calculation. What are the risks and harms of Covid-19 compared to the benefits and risks / harms of the vaccination?

The path to herd immunity takes time and patience. In order to reach the stage when un-vaccinated people are sufficiently protected by immunised people, many, many more need to achieve immunity, whether through vaccination or recovery from the virus. Even then, outbreaks are still likely to occur among the non-vaccinated or insufficiently immunised population. Professor Dr Claude Muller, virologist at the Luxembourg Institute of Health (LIH), describes it thus:

"A choice between the virus and vaccination"

"From my point of view, there is a choice between the virus and the vaccination. Of course, you could isolate yourself completely for a long time, stop travelling, and reduce personal contacts to an absolute minimum. But this does not seem practical to me, especially for the population of Luxembourg, who travel frequently."

We therefore asked the question: what happens statistically when a person is infected? And what happens when that person is vaccinated? Rather than focusing merely on percentages and probabilities, we compared 100,000 people sick with Covid-19, with the same number of people vaccinated against Covid-19.

The data situation is still complicated. A large number of sources were identified for this article and compared with one another. Although the data is expected to become more advanced as the vaccine rollout continues, the situation presented here is fairly clear already. Both the virus and vaccines present a certain number of risks, but it is apparent that the virus is more likely to risk serious illness than the vaccine. That said, more studies and data will be required to achieve even more precise figures. 

Overview of Covid-19 symptoms

The chart shows the proportion of 100,000 Covid patients who suffer from selected symptoms, as well as those who developed a serious illness, Long Covid, and Covid fatalities. The numbers vary depending on the examinations used.

Overview of vaccination reactions and complications

This chart depicts the number of people who experienced symptoms or complications following a SARS-CoV-2 vaccine (either BioNTech / Pfizer Comirnaty or AstraZeneca). The figures hail from the phase 3 studies used by the EMA for drug approvals. Blood clots in the brain are an exception. While there was nothing in the studies to suggest that any of the approved vaccines could cause such a clot, this link was evident during vaccinations with the AstraZeneca vector virus vaccine. However, just over 220 cases were registered from around 34 million vaccinations.

The figures depicted above are all averages. The risk varies according to age and prior medical conditions.Authors: Kai Dürfeld (Science RELATIONS ), Jean-Paul Bertemes (FNR)