Who is responsible for the evaluation and monitoring of vaccines (vaccine safety)?
In Germany, the Paul-Ehrlich-Institut is responsible for the authorisation of vaccines, i.e. the evaluation of quality, safety and efficacy as well as pharmacovigilance (drug safety) after authorisation.
The Standing Commission on Vaccination (Ständige Impfkommission, STIKO), located at the Robert Koch Institute (RKI), prepares vaccination recommendations based on data on the efficacy and safety of the respective approved vaccines so that vaccines can be used optimally. For this purpose, the STIKO incorporates the assessments of the Paul-Ehrlich-Institut on the safety of vaccines.
After a vaccine has been authorised, all reports of suspected adverse reactions or vaccine complications are continuously recorded and evaluated. The monitoring of side effects by the Paul-Ehrlich-Institut on the basis of suspected case reports of side effects and vaccine complications assists in the rapid detection of new risk signals for the use of vaccines and other biomedicines. The Paul-Ehrlich-Institut uses pharmacovigilance measures to not only quickly detect new risk signals, but also to take or initiate measures to reduce risks when needed. This is done both nationally and at European level.
The Paul-Ehrlich-Institut publishes on a regular basis safety reports on reported suspected cases in Germany following vaccination against COVID-19.
On how many people were the COVID-19 vaccines tested before they received marketing authorisation in Europe?
At the time that the COVID-19 mRNA vaccines Comirnaty and COVID-19 Vaccine Moderna were authorised for use in the EU, data on efficacy was available from around 14,000 to 18,000 people who had been vaccinated with the respective vaccine in the phase 2/3 trials. In total, more than 30,000 study participants per vaccine product took part in the pivotal (decisive) clinical trial.
At the time that the vector vaccine Vaxzevria (COVID-19 Vaccine AstraZeneca) was authorised for use, data on efficacy was available from around 6,000 vaccinated persons (around 12,000 study participants) from the phase 2/3 studies.
At the time that the vector vaccine COVID-19 Vaccine Janssen (now: Jcovden) was authorised for use, data on efficacy was available from around 19,000 vaccinated persons (around 39,000 study participants).
At the time of authorisation for the protein-based vaccine Nuvaxovid, data was available from approximately 17,000 vaccinees (approximately 25,000 study participants) for the primary efficacy analysis.
For the safety analysis of all the authorised vaccines, data from more than 20,000 study participants (including at least 8,000 fully vaccinated persons) was evaluated; this data covered a period of up to two months after the final dose.
How is the efficacy of a COVID-19 vaccine determined?
During the authorisation-related clinical trial of the safety and efficacy of a COVID-19 vaccine candidate, normally phase 3 or 2/3, the study participants are assigned randomly to one of two groups. One group is vaccinated with the vaccine candidate (the “verum group”), while the control group is given a placebo or another vaccine. Care is taken to ensure that both groups have a similar composition (e.g., in terms of age, gender etc.) and that there is a comparable risk of infection with SARS-CoV-2. The occurrence of a laboratory-confirmed symptomatic SARS-CoV-2 infection, i.e., illness with COVID-19, with effect from a specific point in time after vaccination is then recorded in both groups and the frequency is compared. A calculated efficacy of 90% means that the number of COVID-19 cases that occurred in the vaccinated group was reduced by 90% within a certain time compared to a non-vaccinated control group (e.g. n = 10 vs. 100 cases with groups of the same size).
How great is the efficacy of the COVID-19 vaccines?
The efficacy data underlying the conditional authorisation can be found in the product information of the respective COVID-19 vaccines. The product information can be found at http://www.pei.de/covid-19-vaccines in the right-hand column.
The efficacy studies completed in the authorisation process were conducted at a time when the Omicron virus variant was unknown and not yet widespread. Omicron currently dominates the SARS-CoV-2 infection situation in Germany. The previous studies show that the effectiveness of the COVID-19 vaccination is reduced against an infection with the Omicron variant and Omicron-induced COVID-19 compared to previous virus variants. However, it has also been shown that individuals are significantly better protected against illness caused by the Omicron virus variant after booster vaccination than persons after primary vaccination.
The Robert Koch-Institut, which is responsible for epidemiology, regularly provides information in its frequently asked questions (FAQ) about the current state of knowledge on the effectiveness of COVID-19 vaccines against the currently circulating virus variants.
Have any safety steps been omitted during testing in order to speed up marketing authorisation?
For the marketing authorisation of the COVID-19 vaccines, all the tests relevant to an assessment of the safety of the vaccines were carried out. The quality, safety and efficacy of every single vaccine product must be ensured before a vaccine product can receive marketing authorisation.
The current authorisations for the COVID-19 vaccines are conditional marketing authorisations. This means that on certain dates after the marketing authorisation, additional data must be submitted by the marketing authorisation holder. The Committee for Medicinal Products for Human Use (CHMP) at the European Medicines Agency (EMA) has formulated criteria with regard to which conditions must be met before marketing authorisation can be issued for a COVID-19 vaccine.
Are the COVID-19 vaccines safe, even though they have been developed so quickly?
The short development time for the current COVID-19 vaccine candidates was possible thanks to a number of factors:
- Knowledge of the potentially protective antigen from previous work on vaccines for SARS-CoV in 2002/2003 and MERS-CoV
- Application and further development of new vaccine technologies
- Some otherwise preclinical trials were carried out in parallel to clinical trials
- Performance of overlapping phase 1/2 and phase 2/3 trials
- Regulatory guidance through intensive and in some cases repeated scientific advice
- Rolling review at the Paul-Ehrlich-Institut and at the European Medicines Agency (EMA)
- High level of focus and generous financial support from the German Federal Government, the European Commission and global charitable foundations which also enabled large-scale manufacture to commence prior to marketing authorisation
- Worldwide cooperation, e.g. at the level of the WHO and the International Coalition of Medicines Regulatory Agencies (ICMRA)
- For the marketing authorisation of the COVID-19 vaccines, data was evaluated from between 20,000 and almost 40,000 study participants. This allowed extensive information to be gained on the safety and efficacy of the vaccines.
The follow-up monitoring of the study participants does not end with marketing authorisation. They will be actively monitored over a period of up to two years as part of the ongoing clinical trials tied to the authorisation process. One of the reasons for doing this is to evaluate how long the efficacy of the vaccination will last.
In general, however, it is the case with COVID-19 vaccines, as with all other new vaccines and therapeutic medicinal products, that not all very rare adverse reactions can be recorded at the time of marketing authorisation. For this reason, the safety of vaccines, like that of other newly authorised medicinal products, continues to be checked after marketing authorisation. One element of this follow-up monitoring (surveillance) is, for example, the analysis of spontaneous reports of suspected adverse reactions or vaccination complications. For the pandemic COVID-19 vaccines, other studies are also being carried out, including active safety studies.
Do we need to fear long-term effects of vaccines that occur years after vaccination?
Decades of experience has shown that most vaccine side effects occur within a few hours or a few days after a vaccination. In rare cases, vaccine side effects occur or are recognised only after weeks or a few months.
The first available COVID-19 vaccines in Europe were authorised in late 2020 or early 2021 and have been in general use since. The first clinical trials began several months before authorisation. Since then, the vaccines have been administrated millions or even billions of times. These vaccines and their side effects are now well known - including very rare side effects.
What are long-term effects anyway?
There are two possibilities of what is meant by the term "long-term effects". Something that only occurs after a long time, or something that lasts over a long period of time.
A desirable long-term consequence of vaccination in the sense of a long-lasting effect is protection against infection or serious illness. For some people, this protection even lasts for life - for example, with the measles vaccination. For other vaccinations, such as against influenza - and according to the current status also against COVID-19 - booster vaccinations are necessary. Together, however, the vaccinations lead to continuous protection against the pathogen.
In individual cases, even very rare vaccination complications can last a long time, possibly years. However, this is the absolute exception. An example of such an extremely rare side effect with a long-term effect is the very rare occurrence of narcolepsy after vaccination against swine flu in 2009/2010 and is an absolute exception. Here, too, the first indications of this vaccination complication occurred only a few months after the start of the vaccinations.
Concerned citizens understand long-term consequences - often also called late effects - to mean side effects that occur only after a delay of many months or years after vaccination. These concerns are unjustified. We are not aware of such very late-onset side effects of vaccines.
What is the risk of mRNA vaccines integrating into the genome?
There is no discernible risk of mRNA integrating into the cell genome. The genome, which consists of DNA, is located in the cell nucleus, where vaccine mRNA does not normally reach. RNA itself cannot be integrated into the DNA genome. Therefore, the mRNA would first have to be transcribed into DNA in the cell in order to be integrated into the human genome. Theoretically, an integration of the mRNA into the genome of cells would only be possible in the presence of certain proteins, which could transcribe the vaccine mRNA into DNA, then transport this DNA into the cell nucleus and there in turn integrate it into the genome by means of a virus protein. This is an extremely unlikely and hitherto unobserved sequence of reactions in unmodified cells. Furthermore, the mRNA in the cells of a vaccinated individual is only temporarily present in the cells of the vaccinated person before it is degraded.
Why do the mRNA vaccines authorised contain lipid nanoparticles?
The currently authorised COVID-19 mRNA vaccines – Comirnaty and COVID-19 Vaccine Moderna – contain lipid particles in which the mRNA is encapsulated. On account of their size (< 100 nm), they are also referred to as lipid nanoparticles (LNPs). When using the term “particle”, however, it should be noted that these are not non-degradable solid particles (metals, plastics etc.), but rather fat globules that, like biological cell membranes, are made up of a phospholipid layer. They act as carriers and protect the otherwise unstable mRNA. Above all, however, they ensure that the mRNA is absorbed into the cells after vaccination (especially around the injection site) and is then released within the cell where the mRNA is to be transcribed.
What do we know about the safety of lipid nanoparticles in mRNA vaccines?
Lipid nanoparticles (LNPs) are similar to the liposomes (fat cells) that have been used for over 20 years as delivery mechanisms for medicinal products (e.g. Myocet liposomal, Caelyx pegylated liposomal, DaunoXome, AmBisome). In another authorised medicinal product, therapeutic RNA molecules are encapsulated in very similar LNPs (Onpattro). With these medicinal products, significantly higher amounts of lipids are administered intravenously compared to vaccination. There have also been authorised vaccines with a similar structure, called “virosomal vaccines”, e.g. Epaxal for hepatitis A or Inflexal for influenza. Virosomes are also phospholipid vesicles that carry viral envelope proteins on their surface. We have many years of experience with these vaccines and they have a good safety profile. At present, they are no longer on the market, but this is not the result of safety concerns.
As with biological membranes, the structure of LNPs is formed by phospholipids with cholesterol stored in them. The various LNPs also contain other lipid components that impart special characteristics. As all lipids are identical or very similar to the body’s own lipids, LNPs are considered to be “biodegradable”, i.e. it may be assumed that, similar to dietary lipids, they are broken down in the body enzymatically and are largely incorporated into the body’s own fat metabolism.
The potential toxicity of each of these novel vaccine preparations was tested in preclinical toxicity tests prior to marketing authorisation.
Do the vaccines contain microchips/nanochips?
Is it true that Comirnaty (BioNTech/Pfizer) and Spikevax (Moderna) use excipients that are not allowed in medicines?
The substances ALC-0315 and ALC-0159 in the Comirnaty (BioNTech/Pfizer) vaccine and SM-102 in the Spikevax (Moderna) vaccine are pharmaceutical excipients. Pharmaceutical excipients can be produced by the pharmaceutical manufacturer itself or purchased from other companies. Such substances are sometimes offered as laboratory chemicals for a wide variety of applications. The manufacturer usually provides the product information on these laboratory chemicals with a warning that they are not suitable for use on humans. This can lead to the erroneous assumption that they generally cannot be used in humans.
As soon as such substances are used in medicinal products, their suitability for use in humans must be carefully examined and evaluated by the manufacturer and within the framework of the marketing authorisation, e.g. by the Paul-Ehrlich-Institut. A marketing authorisation application contains corresponding information on quality and production. The above-mentioned testing was also carried out as usual for the approval of mRNA vaccines.
How is the safety of the vaccines monitored after marketing authorisation?
At the time of the first marketing authorisation, our knowledge of the safety of the COVID-19 vaccines is naturally incomplete, because in clinical trials both the duration of the follow-up monitoring and the number of vaccinated persons are limited. It is possible that not all the rare or very rare adverse effects associated with administration of the vaccine have been identified in the clinical trials. They are, however, of great importance for the overall evaluation of a new vaccine. In general, new knowledge about the safety of vaccines, especially with regard to very rare occurrences, can be obtained even a long time after marketing authorisation – as is the case with all vaccines. For this reason, experts in the safety of medicinal products (pharmacovigilance) never stop monitoring the vaccines, even after marketing authorisation.
Routine pharmacovigilance measures after marketing authorisation include the recording and evaluation of reports of suspected vaccination complications or adverse reactions to vaccination. These reports are recorded and evaluated centrally both at the Paul-Ehrlich-Institut and in the EudraVigilance database for the whole of Europe. In this connection, the marketing authorisation holder must regularly prepare safety reports, which are assessed jointly by the various marketing authorisation agencies in the European Union. As part of marketing authorisation, the marketing authorisation holder must submit “risk management plans”, which summarise what is known – and what is not yet known – about the safety of the vaccines. In addition, it must describe precisely the measures that will be used to fill the remaining gaps in knowledge – e.g. further studies after marketing authorisation – and in what timeframe this will be achieved. These gaps in knowledge may, for example, relate to safety in particular groups of people who were not represented sufficiently in the clinical trials.
In the case of the COVID-19 vaccines, the Paul-Ehrlich-Institut is also carrying out additional studies. This includes a study using the SafeVac 2.0 smartphone app, which will be used to further investigate the tolerability of the individual COVID-19 vaccine products. Participation in the app-based study is voluntary.
When does vaccination protection begin with the authorised COVID-19 vaccines?
In the clinical trials for the marketing authorisation of the respective vaccines, complete vaccination protection against COVID-19 was detected seven to fifteen days after the second vaccination or two weeks after the single vaccination with COVID-19 Vaccine Janssen. However, with all the vaccines a certain level of protection against COVID-19 was already evident after the first vaccination.
Which vaccination reactions may occur after a vaccination with the authorised COVID-19 vaccines?
The safety of the vaccines is examined intensively both during and after the authorisation process. Information on the frequency and type of side effect(s) observed and vaccine complications can be found in the relevant technical information (section 4.8).
Possible expected vaccine reactions and knowledge about possible rare vaccine complications are also stated in the information leaflet that is given to people receiving the vaccine before vaccination for the respective vaccine as part of the information they receive (see further information).
Should allergy sufferers be vaccinated?
According to current knowledge, allergy sufferers or people who have already experienced a severe allergic reaction (anaphylaxis) can be vaccinated against COVID-19 with all authorised vaccines. There is no increased risk of serious adverse effects. An exception is a pre-existing allergy to an ingredient of the specific COVID-19 vaccine or a severe intolerance reaction to previous administration of the COVID-19 vaccine. In this case, allergological clarification is recommended and it is usually possible to switch to another COVID-19 vaccine.
As a general rule, severe allergic reactions can occur in very rare cases with all vaccines. Therefore, each person should be observed for 15 minutes after vaccination so that they can receive appropriate medical treatment in the event of an allergic reaction. If the person to be vaccinated has a history of anaphylaxis or severe allergic reactions following administration of medication or other vaccines, the observation time will be increased to 30 minutes if necessary.
It is not recommended to take anti-allergic drugs before vaccination, as a possible allergic reaction could be delayed and occur outside the monitoring period of 15 or 30 minutes.
In the rare case of a severe anaphylactic reaction after the first or second dose of vaccine, a further dose should not be administered.
Can COVID-19 mRNA vaccines affect fertility?
There is no evidence from the non-clinical studies of the authorised mRNA-COVID-19 vaccines that vaccination could lead to impairment of female or male fertility (fertility).
As required for any drug approval in the EU, various animal toxicity studies were conducted prior to human use. Potential adverse effects of repeated vaccinations on fertility, pregnancy and embryonic development were each investigated in a special, very large study in female rats conforming to international guidelines (so-called ‘DART(Developmental and Reproductive Toxicity) study’). These studies show no evidence of impairment of female fertility caused by the vaccines. Furthermore, in the toxicity studies with repeated administration of an increased vaccine dose (so-called ‘repeat-dose toxicity study’), no vaccine-related changes in female or male reproductive organs (ovaries or testicles) were observed in the subsequent comprehensive fine-tissue (histopathological) examinations.
With this data situation, the best possible safety for the exclusion of damage to reproductive organs and of an impairment of reproduction in humans is guaranteed within the framework of a drug marketing authorisation.
The studies conducted and their evaluation can be found in the published European public assessment report (EPAR) of the European Medicines Agency (EMA). The EPARs can be found in the right-hand column at http://www.pei.de/covid-19-vaccines. The Robert Koch-Institut reports on further studies in their report (German only): “Does COVID-19 vaccination make men or women infertile?”
Is there a risk that the DNA from vector vaccines can be integrated into the human genome?
The COVID-19 vaccines Vaxzevria from Astra Zeneca and COVID-19 Vaccine Janssen consist of viral vectors from adenoviruses (cold viruses). The genome of the adenovector was modified in such a way that virus propagation in human cells is not possible and, at the same time, the gene with the antigen blueprint (immunoreaction-causing pathogen component) is transferred into the cell. After the adenoviral gene transfer, the optimised surface protein of SARS-Coronavirus-2, the spike protein, is produced in a few body cells and presented to the immune system. Adenoviral vectors are generally considered as non-integrating vectors. This means that they do not integrate their genome into the cell genome. Like the genome of other adenoviruses, the genome of the COVID-19 vector vaccines on the basis of non-replicable adenoviruses will remain outside the human DNA (extrachromosomal) in the cell nucleus.
Also, against the background that the adenoviral vectors – unlike natural cold viruses – cannot replicate in the vaccinated person, due to genetic changes, and are rapidly eliminated in the body, there is – based on the current state of the art – no risk of the adenovirus vector DNA integrating into the human genome.
Can COVID-19 vaccination with an mRNA or a vector vaccine cause damaging cell fusions?
The answer is clearly no.
In the meantime, it is known that the spike protein of Coronavirus SARS-CoV-2, when in contact with human cells, causes the cells to fuse with neighbouring ones and partly die. Such fused cells were found in lungs of patients who had died of COVID-19.
With these findings, the question arose whether vaccines causing the formation of spike proteins might also cause such membrane fusions.
When the COVID-19 vaccines available in Germany (mRNA vaccines or vector vaccines) are used, few body cells receive foreign genetic information at one single time. This information consists of mRNA (mRNA vaccines) or DNA transmitted by harmless cold vaccines (vector vaccines). The genetic information is translated into protein by the cells affected. The cells generate the spike protein of Coronavirus SARS-CoV-2. Since the vaccines do not replicate, unlike the Coronavirus SARS-CoV-2, the amount of spike protein will remain small and local. No clinical effects can be expected, because the number of cells, into which the genetic information for the formation of the spike protein is inserted by the vaccination, is so small.
Clinical studies in tens of thousands of vaccinated study participants have proofed the safety of the vaccines. The regular public safety updates by the Paul-Ehrlich-Institut do not include any evidence of such vaccination complications either.
Membrane fusion is a natural process used by the cells to transport material such as hormones, neurotransmitters, and waste to the desired destination. Viruses also use this process to enter new cells.
What are infection-dependent antibodies (ADE)?
Infection-enhancing antibodies (Antibody-Dependent Enhancement, ADE) bind to the surface of viruses but do not neutralise them. Instead, they facilitate the uptake of the virus into the cell and enhance the infection.
The possibility of ADE formation is generally addressed early in vaccine development in both non-clinical trials and clinical trials.
One viral infection in which ADE is occasionally observed is the dengue virus infection. After an initial infection that usually runs uncomplicatedly, the second infection occasionally leads to a severe course that is attributed to ADE. Such amplifications of infection by antibodies can also be induced by the dengue vaccine Dengvaxia when vaccinating people who have no previous immunity to dengue viruses. Therefore, the vaccine is only authorised for use in people who have been infected with dengue virus in the past and live in endemic areas.
Are infection-amplifying antibodies (ADE) a potential problem with COVID-19 vaccines?
So far, there is no evidence of the presence of ADE-induced amplification of infection, either in animal models of SARS-CoV-2 infection, in COVID-19 recovered people or in SARS-CoV-2 infected people. Scientists, including those in the clinical field, continue to closely monitor SARS-CoV-2 infections in vaccinated and recovered individuals. From the beginning of COVID-19 vaccine development, the question of ADE development has been under intense investigation, as there was evidence of ADE development in the preclinical development of vaccines against other beta coronaviruses - SARS-CoV-1 and MERS. There has been no evidence of ADE in any of the COVID-19 vaccines authorised in Europe, either in preclinical development, clinical trials or post-market use.
What is VAED?
VAED stands for Vaccine-Associated Enhanced Disease. On the one hand, it can be caused by the occurrence of so-called infection-enhancing antibodies (Antibody-Dependent Enhancement, ADE). On the other hand, it can be caused by vaccine-associated hypersensitivity (VAH). These processes involve a shift in the balance between different immune cells, the so-called type 1 and type 2 T helper cells, which in turn has consequences for the release of important messenger substances of the immune system.
VAED arose in context with the development of a vaccine candidate against pneumonia in children caused by the respiratory syncytial virus (RSV) more than 50 years ago (1967). There, increased RSV disease with signs of inflammation in vaccinated individuals was noticed in the clinical trials. The development of the vaccine was stopped early for these reasons.
Is there any evidence for the development of VAED (Vaccine associated enhanced disease) with the COVID-19 vaccine?
No. There is no evidence of enhanced COVID-19 disease in vaccinated individuals, either in clinical trials with COVID-19 vaccines or in the context of the now widespread use of COVID-19 vaccines in the general population. Also, studies in animals of different species infected with SARS-CoV-2 after vaccination have shown no evidence of VAED.
Is it possible that quality defects in individual batches (production units) could cause adverse events and vaccination complications and would this be detected?
Samples from each vaccine batch are experimentally tested by a European Official Medicines Control Laboratory (OMCL). The Paul-Ehrlich-Institut only grants national batch release for the German market if the samples meet the criteria and specifications stated in the marketing authorisation documentation. This ensures a high level of quality for each batch of the vaccine products. To date, there is no evidence that individual batches were associated with a higher number of adverse events or any specific adverse events.
Where can I find information about the substances contained in vaccines?
The Summary of Product Characteristics (SmPC) is one place where information on the substances contained in a vaccine can be found.
The "Guideline on Summary of Product Characteristics (SmPC)" from the European Medicines Agency (EMA) specifies what must be stated in each medicinal product's SmPC (see below under "Further Information").
Detailed information is listed under the following points:
- Section 2: Qualitative and quantitative composition:
The active substance(s) are mentioned here. The information is to be provided qualitatively and quantitatively, i.e. in terms of type and amount.
In the case of vaccines, section 2 also includes adjuvants. Adjuvants are by definition excipients (see section 6.1). However, full qualitative and quantitative details for excipients listed in the "Annex to the European Commission guideline on ‘Excipients in the labelling and package leaflet of medicinal products for human use’" must also be provided under section 2 of the Summary of Product Characteristics (see below under "Further Information").
- Section 4.3: Contraindications:
Circumstances in which the medicinal product should not be given for safety reasons are listed in this section. The list includes a warning for hypersensitivity to the active substance or to any excipients. For example, components that can lead to allergic reactions are mentioned in this section.
- Section 6.1: List of excipients:
The excipients are listed here. According to the European Pharmacopoeia (Ph. Eur.) 10.7, an excipient is any substance contained in a medicinal product other than an active substance (examples: adjuvants, stabilisers, antimicrobial preservatives, diluents, antioxidants). Adjuvants are listed under section 2 (see above).
Residues from production or impurities need not be reported if they do not pose any identifiable risks.
Residues with which a risk could be associated, such as traces of antibiotics or traces of egg whites, must be reported due to possible anaphylactic reactions (severe immune reactions). These substances must also be mentioned under section 2 (qualitative, not quantitative). For such substances, there is a warning in section 4.4 as a precautionary measure to reduce the risk during use.
Elemental impurities in pharmaceuticals (e.g. metal traces) are considered acceptable up to certain limits. This is regulated in the ICH Q3D Elemental impurities guideline.
Tables A.2.1 and A.2.2 in the document show the PDE values (permitted daily exposure) in micrograms (μg)/day for different elements.
Quantities in excess of these values shall be justified by the applicant in exceptional cases. A level of elemental impurities above the specified PDE value (see Table A.2.1) may be acceptable in certain cases. These cases include intermittent (temporary) administration, short-term administration (i.e. 30 days or less), special indications (e.g. life-threatening diseases, unmet medical needs, rare diseases).
If doses of a vaccine batch (production unit) contain concentrations of elemental impurities that are too high and do not fall under the exceptions mentioned above, the vaccine batch does not receive a federal batch release for Germany from the Paul-Ehrlich-Institut.
The term "Post-Vac Syndrome" is used in connection with certain symptoms observed after COVID-19 vaccination, some of which are similar to Long COVID symptoms.
Currently there is no internationally recognised, standardised case definition for Post-Vac Syndrome. The causes of both Post-Vac Syndrome and Long COVID are unknown.
The recording and categorisation of suspected cases is carried out according to the internationally agreed codes of the "Medical Dictionary for Regulatory Activities" (MedDRA). This creates an electronic, standardised record of all reports corresponding to these codes.
The Paul-Ehrlich-Institut carried out evaluations of international suspected cases from 36 countries using the adverse reaction database (EudraVigilance database) at the European Medicines Agency (EMA). The Paul-Ehrlich-Institut searched for suspected cases of Chronic Fatigue Syndrome, Postural Orthostatic Tachycardia Syndrome, Post-Acute COVID-19 Syndrome and Post-Vaccination Syndrome. In view of the large number of vaccinations that have been carried out, the number of suspected case reports is not unusually high, and a risk signal has not yet emerged on the basis of national and international reports.
Experience with COVID-19 vaccinations, some of which number in the billions, has been gained worldwide in very different healthcare systems (Scandinavia, USA, Asia, Israel, etc.). Therefore, it can be assumed that new risk signals would be detected very quickly. Examples of these are the very rare (<1/10,000) side effects:
- anaphylactic reactions,
- thrombosis with thrombocytopenia syndrome (TTS) after vaccination with adenovirus-based vaccines, in particular in persons under 50 years of age,
- myocarditis, mainly occurring in subjects under 30 years of age after the second dose of mRNA vaccine and
- Guillain-Barré syndrome (GBS) after vaccination with adenovirus-based vaccines.
In addition, there are now studies that suggest that COVID-19 vaccines can protect against Long COVID.
For example, in a study conducted by the Office for National Statistics in the United Kingdom (UK) in which patients were interviewed, the risk of Long COVID was lower in vaccinated individuals who experienced SARS-CoV-2 infection after vaccination than in unvaccinated infected individuals.
In order to scientifically classify and evaluate "Post-Vac Syndrome", further methodologically robust investigations or studies are necessary. Such studies are the only way to gain reliable insights into the possible causes of Long COVID and Post COVID-19 after infection, as well as the reactions currently referred to as Post-Vac Syndrome after COVID-19 vaccination, which has very similar symptoms to Long COVID.
How do the Omicron BA.1 variant-adapted, bivalent mRNA vaccines Comirnaty Original/Omicron BA.1 (BioNTech/Pfizer) and Spikevax Bivalent Original/Omicron BA.1 (Moderna) differ with regard to the efficacy and tolerability to the previous mRNA vaccines?
Both vaccines show a tolerability comparable to that of the previous vaccines. There is no evidence of new, previously unknown side effects.
Both booster vaccines increase the blood levels (titres) of neutralising antibodies compared to the original SARS-Cov-2 variant (Wuhan) and the Omicron virus variant BA.1 along with other Omicron subvariants including BA.4/5.
In accordance with the authorisation requirements for the respective variation of the monovalent vaccine Comirnaty (BioNTech/Pfizer) or of the monovalent vaccine Spikevax (Moderna), a higher immunogenicity (meaning higher neutralising antibody levels) against the Omicron variant BA.1 was observed in clinical trials of the Omicron-adapted bivalent booster vaccine with BA.1 component as was observed after booster vaccination with the respective monovalent COVID-19 vaccine with the original virus antigen (Wuhan).