Reports of suspected adverse reactions to COVID-19 vaccines in Switzerland – update
Reporting period 01.01.2021 – 21.07.2021
4,319 reports evaluated – the overall positive benefit-risk ratio of the vaccines remains
Up to 21 July 2021, Swissmedic evaluated 4,319 reports on suspected adverse drug reactions (ADR) to COVID-19 vaccinations in Switzerland. The majority of the reports involved more than one reaction. At 2,782 (64.4 %), most of the reports were classified as not serious, while 1,537 (35.6 %) reports were classified as serious.
Evaluated reports on suspected adverse drug reactions
Total number of reactions
2,782 (64.4 %)
Reports classified as non-serious (for all COVID-19 vaccines)
1,537 (35.6 %)
Reports classified as serious (for all COVID-19 vaccines)
Vaccinated people with at least 1 dose (19.07.2021)
Most of the reports were submitted by medical professionals, while a relatively large number (1,109, or 25.7 %) came directly from those affected, i.e. the patients.
The average age of those affected was 60.2 years (range 16–101), with 25.7% aged 75 or over. In the cases classified as serious, the average age was 63.7 years, and for reports temporally linked to a death it was 80.5 years. In 128 serious cases, the people concerned died at differing intervals after receiving the vaccine. Despite a chronological correlation, there is no concrete evidence to suggest that the vaccination was the cause of death.
The majority of the reports concerned women and there were a few cases where no gender was specified.
Evaluations of individual vaccines
1,632 (37.8 %) reports involve Pfizer/BioNTech’s Comirnaty®, while 2,611 (60,4 %) are associated with Moderna's COVID-19 vaccine. In 76 (1.8 %) cases, the vaccine was not specified.
Number of reports by vaccine
of which non-serious
of which serious
Total number of reactions
COVID-19 Vaccine Moderna®
1823 (65,5 %)
45 (3 %)
1537 (100 %)
Number of doses of COVID-19 vaccines given in Switzerland and the Principality of Liechtenstein up to 19 July 2021
Total vaccine doses
Number of people who have received one vaccine dose
Number of fully vaccinated people
2 929 334
1 576 285
1 353 049
COVID-19 Vaccine Moderna®
5 664 149
3 144 602
2 519 547
Organ systems most frequently affected/ most frequent adverse effects
Overview of reported reactions for the vaccine COVID-19 Vaccine Moderna
Ranking of the 15 organ systems most frequently affected
General disorders and administration site conditions (10018065)
Nervous system disorders (10029205)
Skin and subcutaneous tissue disorders (10040785)
Musculoskeletal and connective tissue disorders (10028395)
Gastrointestinal disorders (10017947)
Infections and infestations (10021881)
Respiratory, thoracic and mediastinal disorders (10038738)
Vascular disorders (10047065)
Cardiac disorders (10007541)
Psychiatric disorders (10037175)
Blood and lymphatic system disorders (10005329)
Immune system disorders (10021428)
Eye disorders (10015919)
Metabolism and nutrition disorders (10027433)
Reproductive system and breast disorders (10038604)
Ranking of the 15 most frequent adverse effects
Reported prefered terms (MedDRA)
Injection site erythema (10022061)
Skin reaction (10040914)
Injection site pain (10022086)
Injection site swelling (10053425)
Injection site pruritus (10022093)
Herpes zoster (10019974)
The reports of adverse reactions received and analysed to date do not alter the positive benefit-risk profile of the COVID-19 vaccines used in Switzerland. This largely confirms their known side effects profile. Known side effects of COVID-19 vaccines are listed in the continually updated medicinal product information texts published on www.swissmedicinfo.ch.
The reports of suspected adverse drug reactions (ADR) to COVID-19 vaccinations are evaluated in collaboration with the regional pharmacovigilance centres and in particular with the Ticino reference centre (EOC cantonal hospital authority).
The next report of suspected adverse reactions of COVID-19 vaccines in Switzerland will be released on 13 August 2021.
Information on individual safety aspects
Reports of suspected myocarditis/pericarditis
International discussions are currently taking place regarding cases of myocarditis and pericarditis occurring in connection with the two mRNA COVID-19 vaccines used in Switzerland to date. Swissmedic announced the first reports of this kind in Switzerland on 4 June. Swissmedic and international experts now believe that these could be rare adverse reactions with a mild progression in most cases. Information to this effect will be added to the product information for the two vaccines.
Reports of suspected reactivation of herpes zoster (shingles)
In its regular updates, Swissmedic provided information on reports of reactivation of herpes zoster that occurred with a temporal link to the vaccinations. These individual cases have been carefully evaluated, and "observed-versus-expected analyses" carried out. These analyses allow us to further investigate whether the number of reported cases of a certain reaction or illness exceeds the number of cases that would be expected in a population group even without vaccination.
The investigations so far do not indicate any actual increase in reactivations of herpes zoster following a COVID-19 vaccination in Switzerland. It is therefore currently assumed that cases of herpes zoster are more likely to be coincidental rather than an adverse effect of the vaccines. Swissmedic continues to carefully monitor these reactions as well as international developments in this regard, and will provide more information should new aspects become apparent.
Reports of suspected effects on the menstrual cycle
Swissmedic has received reports of various forms of menstrual irregularity or menstrual cycle complaints following vaccination against COVID-19. Observations of this kind have been reported and discussed in the media and Internet forums both in Switzerland and internationally. Almost all of the reports from Switzerland came from the women affected themselves. Reports of these suspected effects continue to be carefully analysed.
The occurrence of menstrual irregularities in connection with infections or vaccinations, for example, can be a sign that the body is adapting to the – desired – activation of the immune system. These are temporary effects and do not pose any threat. It is important to point out that reactions such as spotting or post-menopausal bleeding can also be warning symptoms of diseases that need to be investigated and have occurred only coincidentally around the time of the COVID-19 vaccination. In such cases it is essential that patients obtain medical advice.
Given the methodology of the spontaneous reporting system, the following factors need to be taken into account when interpreting the data presented here:
The figures provided relate to suspected reactions reported to Swissmedic and entered in the database after being reviewed.
All the reactions reported are suspected cases. In individual cases it has not been ascertained whether the reported reaction was only observed in a temporal relationship with the vaccination or was actually caused by it.
The number of suspected cases for each vaccine can depend greatly on how many people received this vaccine in the period in question.The nu mber of vaccination reactions could be higher than the number of reports. Depending on the authorised use (e.g. age group, high-risk individual) and the latest vac cination recommendations, certain vaccines are more frequently administered to people with a serious preexisting condition.
This can influence the occurrence of certain reactions which, however, are only indirectly related to the particular vaccine.
The figures for suspected cases of vaccination reactions are just one of many elements used to monitor the risk-benefit profile of vaccines. Only a detailed scientific evaluation of all the available data will enable the correct conclusions to be made about a vaccine’s safety profile.