Two recent studies have explored the adverse reactions associated with COVID-19 vaccines. The initial study determined that prevalent side effects include inflammation at the injection site, discomfort, and lethargy, with a higher frequency among women, individuals between 25-35 years of age, and those who had contracted COVID-19 previously. The subsequent study revealed that 30% of menstruating women noticed alterations in their menstrual cycles post-immunization, although a causal link has not been definitively established.
Following their inoculations against COVID-19, Danish citizens reported experiencing mild symptoms such as general unease, increased body temperature, and fatigue. Severe reactions like facial paralysis and allergic incidents are uncommon. Additionally, 30% of women who menstruate indicated changes in their menstrual cycles post-vaccination.
Two studies investigating the adverse reactions to COVID-19 vaccines have recently been published by Aarhus University.
Both pieces of research are predicated on the Danish BiCoVac cohort, a large-scale database enabling the investigation of a broad section of the Danish populace. One of the studies focused specifically on the immediate adverse reactions following COVID-19 immunization.
The most commonly observed adverse reactions after the initial injection in the deltoid muscle are localized redness and discomfort, experienced by 20% of vaccine recipients. Subsequent doses led to reported fatigue in 22% and 14% of recipients after the second and third doses, respectively.
The findings have been disseminated in the scientific journal Vaccine. The research disclosed that frequent symptoms like malaise, fever, and fatigue are among the most commonly reported adverse reactions post-COVID-19 immunization in Denmark. More severe reactions such as facial paralysis and allergic episodes are relatively rare.
Research assistant Kristoffer Torp Hansen and Ph.D. candidate Christina Bisgaard Jensen are credited with publishing studies on the adverse reactions post-immunization against COVID-19. Credit: Simon Byrial Fischel/AU
Kristoffer Torp Hansen, the lead author and research assistant at the Department of Public Health, stated that “Women, individuals aged 25-35, and those who had previously contracted COVID-19 reported experiencing adverse reactions more frequently than men, older individuals, and those who had not previously contracted the virus.”
The data also indicate that immediate adverse reactions differ according to the brand of the vaccine administered.
Recipients of the AstraZeneca vaccine reported a higher number of side effects following the first dose compared to those who received other vaccines.
Conversely, individuals who were administered the Moderna vaccine observed more adverse reactions following the second and third doses, as compared to those who received the Pfizer-BioNTech vaccine.
Several variables influence the reporting of menstrual cycle changes.
The second research study revealed that 30% of women who menstruate noticed modifications in their menstrual cycles after receiving the COVID-19 vaccine.
Upon further investigation, the researchers found correlations between commonly known factors that influence menstrual changes—like stress, age, and tobacco use—and the menstrual alterations reported post-vaccination.
Christina Bisgaard Jensen, a Ph.D. student at the Department of Public Health and the lead author of the study, stated that “Those women who had reservations about the COVID-19 vaccine, had suffered from severe COVID-19 infection, or reported multiple reactions to the vaccine were more likely to report menstrual changes.”
She further clarified that “Although changes in the menstrual cycle are not uncommon, we cannot definitively assert that these reported changes occurred solely due to vaccination.”
“Further research is necessary to ascertain causal relationships and the clinical implications of self-reported menstrual changes,” Jensen concluded.
References:
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“Immediate adverse reactions following COVID-19 vaccination among 16–65-year-old Danish citizens” by K. Torp Hansen, et al., published on 23 June 2023 in Vaccine. DOI: 10.1016/j.vaccine.2023.06.069
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“Prevalence of and risk factors for self-reported menstrual changes following COVID-19 vaccination: a Danish cohort study” by C. Bisgaard Jensen, et al., published on 12 July 2023 in Human Reproduction. DOI: 10.1093/humrep/dead144
The financial backing for both studies was provided by TrygFonden.
Table of Contents
Frequently Asked Questions (FAQs) about COVID-19 Vaccine Side Effects
What are the main findings of the two new studies on COVID-19 vaccine side effects?
The two studies, published by Aarhus University, focus on different aspects of adverse reactions to COVID-19 vaccines. The first study highlights that common side effects include redness at the injection site, pain, and fatigue. These effects were reported more frequently among women, individuals aged between 25-35, and those who had contracted COVID-19 before. The second study reveals that 30% of menstruating women noticed changes in their menstrual cycles post-vaccination, although a causal link has not been confirmed.
Who is more likely to experience side effects from the COVID-19 vaccine?
Women, individuals between the ages of 25-35, and those who had previously contracted COVID-19 reported experiencing side effects more frequently compared to men, older individuals, and those who had not previously had COVID-19.
Are severe side effects common after receiving the COVID-19 vaccine?
No, severe side effects such as facial paralysis and allergic reactions are relatively rare according to the studies.
Do the side effects vary depending on the type of COVID-19 vaccine administered?
Yes, the studies indicate that people vaccinated with the AstraZeneca vaccine reported more side effects after the first dose, whereas those who received the Moderna vaccine reported more adverse reactions after the second and third doses compared to those who received the Pfizer-BioNTech vaccine.
Is there a link between COVID-19 vaccination and changes in menstrual cycles?
The second study revealed that 30% of menstruating women reported changes in their menstrual cycles post-vaccination. However, the study could not establish a direct causal relationship between vaccination and menstrual changes, stating that further research is needed.
Who funded the studies on COVID-19 vaccine side effects?
Both studies were financially backed by TrygFonden.
Where were the studies published?
The first study was published in the scientific journal “Vaccine,” while the second study appeared in the scientific journal “Human Reproduction.”
What is the Danish BiCoVac cohort?
The Danish BiCoVac cohort is a large-scale database that enabled the research on a broad section of the Danish populace. Both studies are predicated on data from this cohort.
More about COVID-19 Vaccine Side Effects
- Immediate adverse reactions following COVID-19 vaccination among 16–65-year-old Danish citizens
- Prevalence of and risk factors for self-reported menstrual changes following COVID-19 vaccination: a Danish cohort study
- Aarhus University Research Publications
- Danish BiCoVac Cohort Study
- Vaccine Journal
- Human Reproduction Journal
- TrygFonden Funding for Research
7 comments
I like how they looked at different vaccines. My husband had Moderna and felt worse than I did with Pfizer. Now i get why.
Found it interesting that women and folks 25-35 are more likely to have side effects. I’m in that age group and experienced fatigue after my shot.
solid research, good to see this kinda detail out there. helps to be informed, especially in times like these.
Wow, these studies r pretty revealing! Makes u think twice about the vaccine, tho it’s good that severe effects are rare.
Are these side effects the same everywhere or just in Denmark? Seems like it’s based on Danish population, so maybe it’s different in other places?
gotta say, reading stuff like this makes me more comfortable about getting the jab. The more u know the less u fear, right.
So the menstrual changes aren’t confirmed to be because of the vaccine? I hope they do more studies on that, it’s important for women to know.