Most vaccine reactions are mild and harmless — but especially for sensitive or anxious clients, they can still cause worry. This blog post is meant to provide some guidance: Which side effects are normal? When should you pay attention? And how can you best handle physical symptoms and inner restlessness? Let’s answer these questions together.

What are common side effects after vaccination?

First, it’s worth distinguishing between a vaccine reaction and a vaccine complication. What we commonly refer to as “side effects” are usually part of the intended vaccine reaction — normal, expected responses of the body to the vaccine. They are usually mild and disappear within a few days.

Why do symptoms occur after vaccination at all? Vaccines contain weakened or inactivated parts of pathogens. They “trick” the body into thinking there’s an infection, which activates the immune system. This is essentially a form of training, so that in a real infection, the immune system can respond quickly and effectively. This activation can cause short-term symptoms.

The most common reactions include local pain, redness, and swelling at the injection site, as well as tiredness and headaches. These usually appear within the first 24 hours after vaccination and typically go away on their own within one to three days.

These reactions are not dangerous — on the contrary, they show that the immune system is responding to the vaccine. Importantly: even without noticeable reactions, the vaccination still works.

Some people also react to medical procedures with a brief fainting episode. This in itself is harmless but can cause falls. That’s why we always administer vaccines while seated or lying down. We also ask our clients in advance whether they’ve ever experienced such a reaction. In these cases, it’s advisable to wait a moment before standing up after the vaccination.

When is it not just a ‘normal’ vaccine reaction?

Mild reactions after a vaccination are completely normal and show that the immune system is working. Severe reactions or lasting vaccine damage, on the other hand, are extremely rare. Still, anyone who notices unusual or intense symptoms should not hesitate to seek medical advice.

When should you be cautious?

Certain signs may indicate a serious allergic reaction. These include:

• Difficulty breathing

• Dizziness or loss of consciousness

• Rapid heartbeat

• Swelling of the face, lips, tongue, or throat

• Widespread rash

These symptoms may indicate a severe allergic reaction that can occur in rare cases — usually within minutes to a few hours after vaccination. This so-called anaphylaxis affects fewer than one person per million vaccine doses but can be life-threatening. In such cases, immediate medical attention is required, and the emergency number (144) should be called.

For this reason, some individuals — especially those with known or uncertain allergies or strong fear of vaccination — remain under observation for 15 to 30 minutes after receiving their shot.

Other reactions are usually harmless

Not everyone needs to worry when they notice changes after a vaccination: apart from allergic reactions, other, usually harmless symptoms may appear.
Local reactions such as swelling, redness, or pain at the injection site are common and harmless. Cooling the area and taking paracetamol can help. Concerning signs include severe or increasing swelling and redness of the injection site accompanied by fever or pus formation. These may indicate an infection at the injection site and should be promptly assessed by a doctor. However, such infections are extremely rare and can be treated if necessary.

Also rare — but worth mentioning for completeness — are heart-related issues such as myocarditis or pericarditis, neurological symptoms such as paralysis or confusion, or persistent high fever (>39°C).

Good to know:

Vaccinations are administered only by trained professionals who know exactly how to respond in an emergency. All vaccination centers and medical practices have immediate access to medical support, and if anything unusual occurs, a doctor is called in right away. This ensures you are well protected even in the very rare case of an emergency.

What to do if you experience side effects

Whether it’s a normal reaction or something more serious can often be judged by the type and duration of symptoms:

• Mild reactions (e.g., pain at the injection site, headache, fatigue) can be treated with over-the-counter medication such as paracetamol.

• If symptoms persist for more than three days, we recommend contacting the clinic where you were vaccinated, your GP, or — for children — your pediatrician.

As a general rule: it’s always better to ask once too often than to worry alone.

When worries take over: the role of the mind

It’s not always the physical reactions that cause distress after vaccination. The mind often plays a big role too. People who are more sensitive to bodily sensations or especially anxious about potential side effects tend to perceive vaccine reactions more intensely — or interpret harmless sensations as something dangerous.

Typical signs of vaccination anxiety or stress reactions include:

• Heart palpitations or rapid heartbeat

• Dizziness, weak knees, or shortness of breath

• Trembling or tingling sensations

• Strong fatigue or tension

These symptoms are real — but they are usually the result of inner tension. Many patients feel relieved when they learn that this is completely normal and will pass on its own.

How we support anxious patients at the Travel Clinic UZH

It is extremely important to us that every client feels taken seriously — whether their concerns are physical or emotional. That’s why we take time for questions, explain procedures carefully, and offer support throughout the process.

Those with a fear of needles can also use a numbing cream or — even more conveniently — a numbing patch (such as Emla) applied to the skin at least one hour before vaccination. This numbs the skin surface and can slightly reduce discomfort at the injection site, although the injection into the muscle may still be felt.

Please inform us in advance if you have a needle phobia. This allows our team to take special measures to make your visit as calm as possible. For a long-term solution, we also recommend professional treatment with a psychologist, as there are very effective therapies available today.

Tips for coping with vaccination anxiety

Here are a few strategies that can help reduce tension:

• Don’t forget to breathe: slow, deep breaths have a calming effect.

• Distract yourself: listen to music or start a conversation with the staff.

• Eat and drink enough: a stable circulation helps prevent dizziness.

• Bring someone along: a familiar person can provide reassurance.

• Avoid Googling symptoms: online searches often create more anxiety than clarity.

• Keep in mind: vaccinations are routine procedures performed safely millions of times every day.

Safe and supported

Vaccinations are among the most effective and safest medical measures available. The vast majority of side effects are mild, temporary, and simply signs that the immune system is active. Serious reactions are extremely rare, and we are always prepared to act immediately if needed.

Just as important as physical safety is emotional wellbeing. Fear or nervousness doesn’t make you weak — it makes you human. That’s why our motto is: Better to ask once too often than to worry once too much.
At our clinic, we want you to feel not only protected, but also cared for.

Still not convinced?

Here are some testimonials from our clients, straight from Google Reviews:

“I am an anxious patient and was very tense before my appointment. Ms. Kiefer gave me my vaccination, and I want to express my great appreciation to her — she was fantastic, compassionate, and took plenty of time for me. I really value that and am very grateful for such caring staff.”*
* Translated from German

 “I visited Travel Clinic with my children for their vaccinations twice, and I couldn't be more impressed with the care we received. The nursing team was absolutely wonderful. My children were quite anxious about getting their shots, but the staff went above and beyond to make them feel at ease. They were so patient and kind, explaining everything in a way that helped ease my children's fears. 

When my son felt a bit dizzy after his vaccination, the staff quickly ensured he was comfortable and monitored him closely until he felt better. Their professionalism and genuine care made all the difference during our visit.
A big thank you to the amazing team!”

«Dear Ms. Kiefer, once again, many heartfelt thanks for taking the time and, with your wonderful manner and great empathy, helping our daughter overcome her fear of vaccinations. She was truly terrified of needles and pain, and it was a very challenging experience for us. It’s wonderful that there are people like you who do their job with passion and go the extra mile when needed. Thank you so much for that! Our holiday in Thailand was amazing :-)
Best regards,
P. Studer”

* Translated from German

References

aha! Allergiezentrum Schweiz. Anaphylaxie (Allergischer Schock). Verfügbar unter: https://www.aha.ch/allergiezentrum-schweiz/allergien-intoleranzen/anaphylaxie-allergischer-schock (Accessed on 30.09.2025).

Bundesamt für Gesundheit (EDI). [Impfschäden in der Schweiz]. Available at: https://backend.edi.admin.ch/fileservice/sdweb-docs-prod-edich-files/files/2024/11/07/0a4c926d-abbe-4b88-89f1-b03eb066d4d8.pdf (Accessed on 30.09.2025).

Bundesamt für Gesundheit (EDI). [Übersicht: Schwerwiegende unerwünschte Impferscheinungen]. Available at: https://backend.edi.admin.ch/fileservice/sdweb-docs-prod-edich-files/files/2024/11/07/fdbdf473-1fb6-40af-b279-2e3392af09a1.pdf (Accessed on 30.09.2025).

Bundesamt für Gesundheit BAG. Impfungen & Prophylaxe. Available at: https://www.bag.admin.ch/de/impfungen-prophylaxe#Wie-wirken-Impfungen (Accessed on 23.06.2025).

Swissmedic. Patient:innen – Meldung von Nebenwirkungen / Pharmacovigilance. Available at: https://www.swissmedic.ch/swissmedic/de/home/humanarzneimittel/marktueberwachung/pharmacovigilance/patienten-innen.html (Accessed on 23.06.2025)