Overview of Corona vaccines in Europe

Marketing Authorization Requirements for Covid-19 Vaccines:

The European Medicines Agency (EMA for short) is responsible for the approval of Covid-19 vaccines in EU member states. However, the authorities of the countries also cooperate in the approval process.

Just as for the U.S. Food and Drug Administration (FDA), the safety of Covid 19 vaccines is a top priority for the EMA. To be able to guarantee this, large clinical studies are to be conducted on the individual vaccines. The FDA requires an efficacy of at least 50%. In order to combat the further spread and mutation of the viruses, the EMA is prioritizing all approval processes for Covid 19 vaccines and, under a so-called "rolling submission", is offering the possibility for companies to submit some aspects of the marketing authorization application for further processing while the Phase III trial is still ongoing.

Together with the FDA and other drug regulatory authorities, the EMA has agreed that several thousand study participants (also older than 55 years) are needed for the Phase III trials. The trials will mainly enrol people who have not yet been infected with the SARS-CoV-2 virus. Nevertheless, the potential vaccine will also be tested in participants who have already recovered from an infection. All Phase III trials should include interim evaluations to show any risks or nonsignificant effect.

Vaccine types:

Research institutes and companies are working on different types of vaccines. The most common studies involve one of the following three mechanisms of action:

mRNA vaccines:

In this process, a specific gene of the virus is extracted in the form of so-called messenger RNA (mRNA for short), which carries the genetic information for building a protein, and is encased in lipids. After injection, the body reacts with an immune response, whereby the mRNA causes the formation of (harmless) viral proteins. Consequently, this triggers the build-up of immune protection. The advantage of the mRNA vaccine is that a large number of injection doses can be produced very quickly.

Vector vaccine (live vaccines):

Similar to the measles vaccine, harmless viruses serve as the starting point for the production of this vaccine. Without causing disease, these so-called vector viruses multiply in the human body. In the process, researchers attach one or more genes of the surface proteins of SARS-CoV-2 to the vector viruses, which consequently are "clothed" with the virus. Some vector viruses can thereby trigger an immune response in the human body. Other vector viruses do not resemble the SARS CoV-2 virus, but can still cause the production of CoV-2 proteins in cells in which they have invaded. In both cases, immune protection can be built up, which should also ward off a true infection.

Viral proteins (dead vaccines):

Such types of vaccines contain either specific viral proteins or the whole substance of inactive SARS-CoV-2 viruses. Similar to vaccines for hepatitis B or influenza flu, this dead material causes an immune response in the human body, allowing immune protection to build up.

Vaccine Type - Monocomponent Vaccine:

Monocomponent vaccines are vaccines that (unlike the so-called combination vaccine) contain only antigens or toxins of one pathogen of a disease. Therefore, such vaccine types are used to induce a targeted immune protection against one pathogen.

Overview of the relevant vaccines in Europe:

Current information on other patient groups:

Children and adolescents:

For a vaccine to be licensed for minors, it must also be tested with them. Most manufacturers do not start this until results suitable for approval have been confirmed in the phase III study with adults. BioNTech/Pfizer - as the only manufacturer at present - has also tested participants from 12 to 18 years of age in the very first Phase III study. However, the results of this study have not yet been fully evaluated.

Pregnant women:

According to WHO, the available data on BNT162b2 and AZD1222 for pregnant women are not sufficient to assess the vaccine's efficacy or the risks associated with the vaccine during pregnancy. However, WHO adds that it should be noted that the BioNTech vaccine is not a live virus vaccine, the mRNA does not enter the nucleus and is rapidly degraded. For AstraZeneca's AZD1222, WHO adds that this vaccine is non-replicating. Animal studies have been unable to show any effects in pregnancy. Further studies in pregnant women are planned in the coming months.

WHO recommends that BNT162b2 and AZD1222 not yet be used in pregnancy unless the benefits of vaccination outweigh any potential risk of vaccination.

Breastfeeding women:

WHO expects the efficacy of the BNT162b2 and AZD1222 vaccine in breastfeeding women to be similar to that in other adults. However, no data are yet available on the safety of COVID-19 vaccines in breastfeeding women or on the effects of mRNA vaccines at BioNTech for breastfed infants. According to WHO, because BNT162b2 is not a live vaccine and the mRNA does not enter the nucleus and is rapidly degraded, it is biologically and clinically unlikely to pose a risk to the nursing infant. For AstraZeneca's AZD1222, it is currently unknown whether the vaccine passes into breast milk. Because the AZD1222 vaccine is a non-replicating vaccine, it is unlikely to pose a risk to the nursing infant, according to WHO. WHO does not recommend discontinuing breastfeeding after vaccination.

HIV-infected individuals:

No differences in safety risks were reported among participants in phase 2 or phase 3 of the BNT162b2 clinical trial with well-controlled HIV. According to WHO, the available data on the administration of the vaccine are currently insufficient to assess the efficacy or safety of the vaccine for people with HIV who are not well controlled on therapy. AstraZeneca did not include people living with HIV in the primary analyses of the trials. Evaluations of safety in subgroups of HIV-positive subjects are currently awaited for AZD1222

According to the health organization, it is not necessary to test for HIV infection prior to vaccine administration.

Immunocompromised individuals:

Available data are currently insufficient to assess the efficacy of the vaccines or the risks associated with the vaccines in severely immunocompromised individuals, according to WHO. It would be possible that the immune response to the vaccine is reduced, which would alter the efficacy.

Individuals with autoimmune diseases:

Currently, according to WHO, no data are available on the safety and efficacy of BNT162b2 or AZD1222 in individuals with autoimmune diseases, although these individuals would be eligible for inclusion in the clinical trials.

Individuals with current acute COVID-19:

WHO recommends that vaccination of persons with acute symptomatic SARS-CoV-2 be delayed until they have recovered from acute illness and the conditions for quarantine termination have been met. There are currently no data to strengthen a recommendation of a minimum interval between symptom onset and vaccination.

Status: 11.03.2021