General information on COVID-19 vaccines
Here you can read about the COVID-19 vaccines; how they have been developed, how they were approved, and not least how the authorities monitor their safety and possible side effects very closely.in general
Read here about the COVID-19 vaccines that have been authorised in the entire EU and granted a so-called conditional marketing authorisation. More information on efficacy, side effects, the results of the trials based on which the vaccines were authorised, the package leaflet, the summary of product characteristics and questions and answers on the vaccine is available on this page.
These two vaccines are authorised throughout the EU and are included in the Danish COVID-19 vaccination programme:
Two other EU-authorised vaccines were also used in the beginning in the Danish vaccination programme but they were subsequently taken out of the programme.
Information from other authorities
The authorities’ joint website:
Danish Health Authority’s COVID-19 theme page:
Danish Health Authority
Statens Serum Institut (SSI):
Monitoring of COVID-19 (in Danish only)
When the pandemic broke out in 2019, all stops were pulled out to develop vaccines as fast as possible, but without compromising the requirements for documentation of efficacy and safety.
Vaccine development is a complex and lengthy process normally taking up to 10 years. But because of the way in which COVID-19 affected our society, the development took place much faster than normal.
Here you can read more about the development of COVID-19 vaccines.
Development in the EU
The European Medicines Agency (EMA) has mobilised extra resources and assessed COVID-19 vaccine candidates. So-called rolling reviews are done in which the authorities review the companies’ documentation before all trials have been completed. In this way, a vaccine can be ready faster than normal. Read more about how corona vaccines are assessed with a view to obtaining a potential authorisation.
The objective of the EU member states has been – through a concerted effort – to develop, assess and potentially authorise vaccines as fast as possible, with due regard to the same high standards and legal requirements for pharmaceutical quality, safety and efficacy as apply to all other medicines and vaccines.
From idea to authorisation
Once an idea for a vaccine has formed, numerous tests must be conducted before the first dose of an authorised vaccine can be given. In vaccine development, there are different phases that researchers and companies must go through before the potential authorisation of the vaccine.
The researchers must first develop their vaccine candidates, which must then be tested in clinical trials. The more certain researchers become of the vaccine’s efficacy and side effects, the more people are given the vaccine for testing. You can read more about the clinical trial phases here. The phase 3 trials of the corona vaccines were very large and involved tens of thousands of trial subjects globally.
Vaccine development is a complex and lengthy process normally taking up to 10 years. However, due to the extreme effects of the COVID-19 pandemic on the world community, researchers from all over the world, vaccine manufacturers and governments have pulled out all stops in an unprecedented effort to develop COVID-19 vaccines much faster.
Tens of thousands of trial subjects have right until the authorisation tested the COVID-19 vaccines in trials all over the world. All trial subjects have been monitored closely during the trials and have subsequently been monitored for at least one year after the trials ended.
In the EU, independent experts from the EU member states, appointed by the individual European member states, assess the documentation from the vaccine manufacturers’ new trials of COVID-19 vaccines. Once the EMA experts on the Committee for Medicinal Products for Human Use have finished assessing a vaccine candidate, the EMA will recommend the European Commission to authorise the vaccine and issue a conditional marketing authorisation.
Ongoing assessment of trial data
The EMA has initiated an emergency plan according to which the EMA experts can fast-track their review of the documentation of the COVID-19 vaccines’ efficacy and safety without compromising the authorisation requirements.
This is done through a so-called rolling review according to which the vaccine manufacturers submit their data for assessment by the EMA experts as soon as they become available. In the normal authorisation procedure, the companies submit all data together after all tests have been completed. The rolling review means that the procedure can be completed in about 70 days compared to normally 210 days because the companies do not wait for all tests to have finished before submitting their data.
Accelerated Authorisation process for COVID-19 vaccines
The vaccine manufacturers are responsible for ensuring that the design of trials is such that it provides sufficient documentation of the vaccines’ efficacy and side effects. How significant the documentation is considered to be depends, among other things, on the number of trial subjects and the duration of the trials. The trial subjects are also monitored after vaccine authorisation.
When is the documentation of efficacy and safety sufficient?
The vaccine manufacturers are responsible for designing vaccine trials that can provide enough documentation to demonstrate if the vaccine works and what side effects the vaccine causes to make it possible for the drug regulatory authorities to authorise it.
If, for example, a group of 20,000 people are given the vaccine and another group of 20,000 people are given a placebo, it is possible to compare the number of COVID-19 infected individuals in the vaccinated group and placebo group, respectively, to learn more about how well the vaccine protects against infection.
It requires a certain number of COVID-19 infected individuals distributed between the vaccinated subjects and the subjects receiving a placebo to be sufficiently sure about the vaccine’s efficacy.
The COVID-19 vaccines consist of protective ingredients and helping agents which make the body switch on its immune system and produce the antibodies, which the body uses to attack coronavirus. The vaccines also contain stabilisers.
The protective ingredient consists of mRNA. The body produces the so-called spike protein based on the vaccine’s mRNA. This protein then stimulates our immune system to produce antibodies to fight the targeted disease – in this case COVID-19.
In the summary of product characteristics that is supplied with all authorised vaccines, you can read more about the ingredients contained in the vaccine – read more at www.produktresume.dk.
It usually takes many years to develop new medicines, but in connection with the COVID-19 pandemic, it became possible to develop COVID-19 vaccines very fast. We were able to do so because the global community was well prepared in terms of research and preparedness when the pandemic broke out.
The last twenty years have seen a number of serious outbreaks and pandemics caused by viral diseases around the world. In 2002, 29 countries were affected by the SARS outbreak, another coronavirus disease. 2009 saw the outbreak of the H1N1 swine flu pandemic, which is believed to have claimed as many as 200,000 lives; 2012 saw the MERS outbreak (another coronavirus disease) in the Middle East; 2013-2015 saw the Ebola epidemic in West Africa; and 2013-2015 saw the Zika pandemic affecting 86 countries according to the WHO.
The numerous outbreaks have raised the health authorities’ and pharmaceutical companies’ awareness of the need for being able to establish fast emergency responses and measures to control future pandemics. Likewise, the past many years have been focused on developing new vaccine technologies to use for new, unknown viral diseases, and when the pandemic broke out in December 2019, experience had already been made with developing vaccines against similar coronavirus diseases (SARS and MERS).
Success with new vaccine technologies
Several of the COVID-19 vaccines are based on new technologies developed over the past 20 years as part of emergency response efforts to target new pandemics in the future.
One is the mRNA technology used in the Pfizer/BioNTech and Moderna vaccines, two vaccines included in the Danish vaccination programme, another is the adenovirus vector-based technology used, for example, in the vaccines from AstraZeneca and Johnson & Johnson.
These technologies had already been developed before the COVID-19 pandemic broke out but had not before been used in authorised vaccines – except for in the adenovirus vector-based Ebola vaccine, which was authorised in the USA in 2019 and in the EU in 2020.
One of the great advantageous of using mRNA technology is that it makes it possible to very quickly update the vaccine to target it against new corona variants without having to develop a new vaccine from scratch.
Other vaccine technologies in the pipeline
Additional new COVID-19 vaccines are currently being developed and authorised based on various other technologies; for the COVID-19 pandemic is not over but expected to hit us in seasonal waves in much the same way as the seasonal flu.
A new and likely development in the future is vaccines that not only protect us against disease but also against transmission. We can also expect to see vaccines that provide a better cross-protection against several virus variants at the same time, and combination vaccines with protection against corona and influenza in one. Work is also being done to develop, for example, vaccines in spray form and tablet form that might be more suitable to use with young children and other groups who would benefit from these alternative forms rather than vaccine jabs.
In future, the new vaccine technologies could also be used against other types of virus outbreaks and pandemics, and the success of the mRNA technology also paves the way for developing vaccines for other serious contagious diseases in addition to a number of cancer diseases.
Side effects and safety monitoring
Like all medicines, the COVID-19 vaccines can cause side effects. The decisive point is that the vaccine’s potential side effects must not be worse than the symptoms and the disease that the vaccine is intended to prevent. These two concerns are weighed up by independent experts of the European Medicines Agency when they assess if vaccines can be authorised.
If you are vaccinated against a disease, side effects such as discomfort and redness at the injection site, fever and muscle soreness are common. Serious side effects could occur in rare cases. The authorities are keeping a close eye on the vaccines’ safety both before and after authorisation.
The known side effects of an authorised COVID-19 vaccine will appear from the summary of product characteristics and the package leaflet.
Monitoring of the vaccine’s safety after authorisation and roll-out
The monitoring of a vaccine continues for as long as the vaccine is in use. This applies to all medicines. Monitoring already takes place in early laboratory testing and in animal trials, and it is intensified when the trials with human beings begin. Trials with humans, also called clinical trials, are divided into three phases so that the safety can be monitored closely and in a responsible manner.
The Danish Medicines Agency registers, monitors and assesses reports of suspected side effects in Denmark on an ongoing basis. Reports concerning new medicines and vaccines are monitored particularly closely. This also applies to COVID-19 vaccines, and the Danish Medicines Agency is especially prepared for this because many have been vaccinated within a short period of time.
In the first two years after vaccines or other new medicines have been put in use, doctors, dentists, prescribing pharmacists and midwives must report any suspected side effects for patients they are or have been treating to the Danish Medicines Agency (except for suspected side effects caused by medication errors). After this period, the reporting obligation only applies to suspected serious or unexpected side effects.
Other healthcare professionals, patients and relatives can report all suspected side effects to the Danish Medicines Agency. This applies to all medicines, including the COVID-19 vaccines.
Healthcare professionals can report suspected side effects to the Danish Medicines Agency via this page:
Vaccines are monitored throughout the EU
In the monitoring of the safety of COVID-19 vaccines, the Danish Medicines Agency collaborates with the national drug regulatory authorities in the EU/EEA, the European Medicines Agency (EMA), the World Health Organization (WHO) and others.
The drug regulatory authorities and the vaccine manufacturers report suspected side effects to the EMA, from where access is provided to reports of suspected side effects seen in the entire EU/EEA and reports of suspected serious side effects seen in third countries. The Danish Medicines Agency monitors and assesses in collaboration with other European drug regulatory authorities if there are signals of new or changed risks of the vaccines in the European database of side effects.
Joint European assessments of the safety of the vaccines are also made in connection with the periodic safety update reports that vaccine manufacturers are obliged to submit at regular intervals. Here the experts from the drug regulatory authorities in the EU member states assess if there is any new information that calls for changes to the package leaflet. The European Commission then considers the next steps.
When you are vaccinated for COVID-19, you reduce your risk of contracting COVID-19 and falling ill.
At present, there is no scientific evidence that the authorised COVID-19 vaccines may lead to late sequelae in the form of side effects occurring a long time after vaccination. Nor has a signal been raised with the EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) on possible late sequelae in the form of side effects occurring a long time after vaccination.
What to do after vaccination
Mild transient side effects are common after any vaccination and most often completely harmless. This could be discomfort and redness at the injection site, fever and muscle soreness. There is no need to contact your doctor if you experience any of this. If you develop a mild fever this is a sign that your immune system is reacting.
Contact your doctor if you have serious symptoms
If you experience serious symptoms after vaccination, you should contact your doctor. This could be allergic reactions such as breathing difficulties or a rash. Your doctor can assess if the symptoms are caused by the vaccine or other conditions.
Your doctor has an obligation to report suspected side effects of COVID-19 vaccines to the Danish Medicines Agency. Remember that you can always ask your doctor if you are not sure whether the symptoms you have are side effects of the vaccine.
You or a relative can report suspected side effects to the Danish Medicines Agency via a Danish reporting form found here: