Questions and answers on COVID-19 vaccines
The medicines agencies in the EU and around the world collaborate on the authorisation and monitoring of COVID-19 vaccines. Once the vaccines have been authorised, drug regulatory authorities follow up on them by monitoring side effects. Read more in our questions and answers on COVID-19 vaccines.
The vaccines’ efficacy
How effective are the vaccines?
Proof of the vaccines’ efficacy has been obtained in major drug trials with thousands of research participants, and that has led to the approval of the vaccines. The two vaccines used in the public vaccination programme in Denmark gave the research participants in the clinical trials a protection as high as 95 and 94 per cent, respectively. In other words, the vaccines protected 9 in 10 from falling ill with COVID-19. Gradually, the virus has mutated several times, and new variants have been added that are more contagious than the original virus. It has an effect on how high the vaccine's effect is. Besides protecting you against COVID-19 infection, the vaccines primary purpose is to protect you from severe illness and from death. So, if you are one of those who catch the coronavirus despite being vaccinated, you will be less ill with the vaccine than without it.
For how long does the vaccine protect against disease?
Researchers, vaccine manufacturers and the health authorities are constantly monitoring the duration of the vaccine effect. The European Medicines Agency (EMA) recommends that you be revaccinated with a 3rd injection after about six months after the basic vaccination to boost your immunity.
Is the protection the same for everyone?
How well the vaccine works varies from person to person. Your health and age play a part in the protection you will get from the vaccine. When we measure the vaccines’ efficacy to see for how long the protection lasts, we need to take into account which target groups have been vaccinated. Older people or people with a weakened immune system are likely to experience a lower effect compared to younger and healthy people.
Are people contagious after vaccination?
The likelihood of transmitting infection as a vaccinated person is considered to be significantly reduced compared to unvaccinated people.
People who have been fully vaccinated can - like unvaccinated people - pass on infection with new coronavirus via contact infection, eg via the hands, as a result of contact with unclean surfaces. Therefore, it is important to maintain good hand hygiene, whether you are vaccinated or not.
Although the vaccines against COVID-19 are extremely effective, there are no vaccines that protect 100 percent. Therefore, it may happen that a person becomes infected with COVID-19 even though the person has been vaccinated. It is called a breakthrough infection. Studies show that the vaccines provide a high level of protection against a serious course of the disease if you become infected even if you are fully vaccinated, but even though you probably have no symptoms or only mild symptoms - you can infect others. Therefore, it is important that fully vaccinated with symptoms or vaccinated who have had close contact with an infected person are still being tested.
Do the vaccines protect against other emerging virus variants?
The vaccines have so far proved to be resistant to the various emerging virus variants and mutations. New variants could be more contagious making them spread faster among unvaccinated people, but if you are vaccinated you are well protected – also against new variants. The vaccine manufacturers behind the mRNA vaccines are constantly working to adjust their vaccines so that they have the best possible effect against new variants.
Who can be vaccinated?
Should people with allergies turn down vaccination due to the risk of allergic reactions?
People with allergies can generally be vaccinated, unless they have a known allergy to the vaccine’s active substance or one or more of its adjuvants (“helping agents”). If you know that you are allergic to something, your doctor can help you decide if you should have the vaccine.
Allergic reactions to the COVID-19 vaccine occur in very rare cases. This is no different from other vaccines. That is why healthcare professionals are present when you are vaccinated and why you are asked to wait for 15 minutes before leaving the vaccine centre.
Should pregnant or breastfeeding women have the vaccine?
If you are pregnant or breastfeeding, you can have the COVID-19 vaccine. Data from vaccinated women show that the vaccine is just as effective and safe compared to people in the same age group. Pregnant women who catch COVID-19 have a higher risk of severe illness. If you are breastfeeding, you have the same risk of getting COVID-19 than other people in your age group.
The European Medicines Agency EMA and the Danish National Board of Health therefore recommend that pregnant women be vaccinated.
Find out more at the website of the Danish Health Authority.
Does the vaccine impair fertility?
There is no indication that fertility is affected by COVID-19 vaccination. Animal studies were undertaken for some of the vaccines. These studies showed that there were no vaccine-related effects, neither on the female animals’ fertility and pregnancy nor on the foetus’ development before or after birth. Read the summaries of product characteristics of the individual vaccines for further details.
Can people with a weakened immune system be vaccinated?
Yes, but the protection will be lower for some people with a weakened immune system. That is why the Danish Health Authority recommends a third dose for people with a weakened immune system. See the guidelines from the Danish Health Authority.
Are there any types of medicines that should be taken cautiously in connection with vaccination?
If you are on so-called immunosuppressive treatment (used in, for example, cancer and transplant patients and in some cases in patients with auto-immune disease), this could in some cases target that part of the immune system that should be responding to the vaccine. In these cases, individual specialist medical advice and a special vaccination procedure may be required. Certain medicines/treatments also imply that the person concerned cannot have injections into a muscle (e.g. strong blood-thinning treatments). If you have been told that you cannot have injections into a muscle, this applies also to the COVID-19 vaccine. If you receive ordinary blood-thinning treatment, you can have the COVID-19 vaccine.
Should the vaccine be avoided if you have had Botox?
Is it possible to get COVID-19 from vaccination?
No, this is not possible.
How do we know that the new mRNA vaccine technology is safe?
Prior to their approval, the mRNA vaccines were tested in at least 35,000 people, and the vaccines have subsequently been used by hundreds of millions of people. All vaccines are monitored globally just like all other medicines. This way the authorities can intervene in the unlikely event of emerging risks.
Do the vaccines cause side effects?
All medicines have side effects; the COVID-19 vaccine is no exception. But it is essential that the side effects caused by the vaccines are not worse than the symptoms and the disease that the vaccines are designed to prevent. This is being monitored carefully by drug regulatory authorities around the world.
What side effects have been observed for the vaccines?
The most common side effects of the COVID-19 vaccines are generally mild or moderate in nature and improve or disappear within a few days. These would include:
- Pain and swelling at the injection site
- Muscle and joint pain
As with all vaccinations, a small risk of extremely rare allergic reactions and so-called anaphylactic reactions were also observed for the COVID-19 vaccines. These reactions could be serious if they are not treated immediately. That’s why you are asked to wait for at least 15 minutes after your vaccination so that healthcare staff can take care of you should you develop a reaction.
The known side effects of the individual COVID-19 vaccines are listed in the product information (package leaflet and summary of product characteristics) for each of the vaccines.
The Danish Medicines Agency publishes statuses on the side effects reported in Denmark on a weekly basis. Read more about the side effects reported for the vaccines.
Who can report side effects?
Both healthcare professionals and people in general can report suspected side effects to the Danish Medicines Agency. Only a suspicion is needed to report. You can make a report even if you only suspect the symptoms to be caused by a vaccine – you do not have to be sure that it is related. It is not necessary to report it or contact your doctor about common mild and harmless side effects such as discomfort, redness at the injection site, mild fever and muscle soreness, but it is important that you do if you experience something serious or unexpected which cannot be explained by something other than the vaccine.
In the first two years after vaccine roll-out, doctors, dentists, prescribing pharmacists and midwives must report all suspected side effects experienced by their patients to the Danish Medicines Agency. After this period, the reporting obligation only applies to suspected serious or unexpected side effects.
How do you assess if a suspected side effect is caused by the vaccine?
We look at the entire disease course of the patient concerned and examine if the symptoms can be explained by other factors or if the vaccine is the most likely contributor to the symptoms. All reports are registered in a database of side effects. The database is used to assess if a certain pattern is beginning to show, for instance if many reports describe the same type of side effect.
What will the Danish Medicines Agency do if new side effects are identified for one of the vaccines?
If we spot a pattern pointing to changed risks of the vaccines, then we take action. The drug regulatory authorities can:
- Make the Pharmacovigilance Risk Assessment Committee of the EU start an investigation. This is known as raising a signal.
- Add new side effects or recommendations in the product information.
- Restrict who the vaccines are authorised for.
- Suspend the authorisation to pause the vaccine or withdraw the authorisation.
Could the COVID-19 vaccines cause side effects not presenting before a longer period of time?
Theoretically, it cannot be ruled out that unexpected side effects may emerge in the long term, but we know from other commonly used vaccines that almost all side effects occur within the first six weeks of vaccination and that it is very rare for side effects to occur later. For this reason, the drug regulatory authorities do not expect to see side effects emerging a long time after COVID-19 vaccination, but we will continue monitoring the vaccines for as long as they are on the market.
Is compensation available for people who may experience side effects or long-term effects?
As with other types of medicines, you may be entitled to compensation from the Danish Patient Compensation Association.
Do manufacturers of COVID-19 vaccines have the same liability towards European citizens as they have for other types of medicines?
The contracts on the procurement of COVID-19 vaccines negotiated by the European Commission with vaccine manufacturers on behalf of the EU member states are fully compliant with the Community legislation and the directive on product liability.
However, the rules on product liability does not affect the individual patient, the reason being that patients in Denmark have the right to compensation for rare and serious side effects regardless of whether the manufacturer is held liable for a product defect. It is the state that pays compensation to the patient, and the state can subsequently assess if it will file a product liability claim against the manufacturer to cover the costs of compensation.
The vaccines’ ingredients
Are eggs contained in the COVID-19 vaccines?
Do the vaccines contain aluminium?
Does the vaccine contain formaldehyde/formalin?
Do the vaccines contain preserving agents?
No, none of the four authorised vaccines contain preservatives.