There are many reports of the unusual cases of severe blood clots in combination with low platelet counts that have occurred following the Astra Zeneca vaccine in a small number of people.
It is still being investigated whether these events can be counted as side effects to the vaccine, and they are too unusual in Sweden to be included in the Medical Products Agency's statistics.
Fever, headache and chills are known vaccine side effects that usually go away within a few days.
In the statistics on such side effects of the covid vaccine, Astra Zeneca's vaccine, Vaxzevria, is overrepresented by thousands of cases.
It is not entirely certain what Astra Zeneca's overrepresentation is due to, but a partial explanation could be the tendency of the vaccinated to report, according to Ebba Hallberg, unit manager at the Medical Products Agency.
- Many of those vaccinated with Vaxzevria are younger people than those vaccinated with the other two vaccines.
This means that you are more digitally savvy to report.
You are younger and healthier simply than if you may be multi-sick, over 80 years old, live in special housing and may never have used a computer, she says.
Most of those who received the Astra Zeneca syringe work in healthcare.
- It probably increases the tendency to report, because you are more medically knowledgeable and aware of the possibility of reporting suspected side effects, says Ebba Hallberg.
Underreporting is common
There could be a number of side effects with the other covid vaccines.
- In general, there is an under-reporting that is generally known, absolutely.
This does not only apply to the covid vaccine.
The older vaccines against, for example, TBE and seasonal flu can also have side effects, but they are so well known that there is probably a lower tendency to report them.
You are more alert to report side effects of the covid vaccine, says Ebba Hallberg.
- These new vaccines are new drugs under a very large societal focus, which probably increases the tendency to report suspected side effects.