COVID-19 vaccines are safe

In a matter of just a few months, biotechnology companies round the world developed a whole range of COVID-19 vaccines. Read on to find out why they are safe despite the very short time involved.

It usually takes years for a new vaccine to be developed and approved. But in the case of the COVID-19 vaccines, things happened – and are happening – far faster. When the pandemic broke out, it soon became clear that vaccines would be the most effective way to control the spread of infection and protect people from catching the disease. This realisation led to the processes involved in developing vaccines being made more efficient and to experts working more closely together around the world. Processes were optimised and development times were shortened, but without compromising in any way on safety.

Available COVID-19 vaccines

The COVID-19 vaccines currently approved for use in Europe are categorised into three vaccine types: mRNA vaccines, vector-based vaccines and protein-based vaccines. Other vaccines currently in the approval process contain components of the spike protein found on the surface of SARS-CoV-2 viruses or the dead virus along with various adjuvants (effect enhancers).

COVID-19 vaccines in use in Germany

The EU has approved five COVID-19 vaccines so far. Other promising vaccine candidates are currently in the final phases of clinical trials. These include vaccines for which documentation has been provided to the European Medicines Agency (EMA) as part of the approval process or for which an initial application for approval has been submitted.

Good to know: All approved COVID-19 vaccines provide a reliable level of protection against a severe COVID-19 infection requiring hospitalisation – a booster vaccination significantly increases the level of protection provided. COVID-19 vaccinations are available throughout Germany free of charge.

Five COVID-19 vaccines approved

How the COVID-19 vaccines work

All vaccine candidates are based on the same underlying principle. They introduce a characteristic of the coronavirus (antigen) to the immune system or trigger the body to produce one, thereby forcing it to produce antibodies and defence cells against the antigen and so against the virus. This generates a protective immune response.

Vaccine effectiveness confirmed in studies*

In the example of the mRNA vaccine from BioNTech/Pfizer In the approval study conducted by BioNTech/Pfizer, participants were divided into two groups. One group received a placebo, the other the vaccine from BioNTech/Pfizer. None of the participants knew if they had received the placebo or the vaccine. In the course of the study, researchers observed how many participants contracted a COVID-19 infection. It was shown that of the individuals who were found to have a COVID-19 infection, 95% had received the placebo and only 5% had the BioNTech/Pfizer vaccine. This leads to the conclusion that vaccination using the COVID-19 vaccine from BioNTech/Pfizer had prevented infection in 95% of cases. In other words, it showed a vaccine effectiveness of around 95%.

Strict safety standards in the EU

All vaccines must be harmless, safe, effective and thoroughly tested before they receive market authorisation in the EU or in Germany. Pharmaceutical companies must provide such proof primarily in the form of pre-clinical studies and clinical trials. Consistent quality of a vaccine and the associated product process also play important roles. The study programme takes in three phases.

The three-phased study programme in developing COVID-19 vaccines

Phase I studies: In initial clinical trials, safety and tolerability of new vaccines candidates are tested on humans in a small study population of less than 100 healthy adults. Tests are also conducted to see if a desired immune reaction can be triggered. During the COVID-19 pandemic, several hundred subjects were enrolled in the studies and combinations were linked with clinical trials in Phase II.

Phase II Studies: This phase usually involves studies on dose finding, immunogenicity and tolerability of a vaccine in a larger number of subjects (several hundred). The aim is to further investigate the knowledge gleaned on tolerability and immune response (formation of antibodies and cellular immune response) for specific doses. Combinations with clinical trials in Phase III were included with several thousand participants.

Phase III Studies: Clinical trials to prove the level of protection against COVID-19 infection and also the vaccine’s safety are conducted on several thousand to several tens of thousands of subjects in different age groups.

In Germany, a vaccine is only approved if all three phases of the clinical study programme are successfully completed and a positive risk-benefit ratio can be proven. As with all vaccine candidates, both national and international quality standards apply – also when approving a COVID-19 vaccine.

During the pandemic, the evaluation procedure that is part of the approval process was accelerated by means of a rolling review approach in order to protect the population against serious illness faster. The requirements regarding the quality, harmlessness and effectiveness of COVID-19 vaccines all apply unchanged.

Potential adverse effects

Theoretically, adverse effects from vaccines (side effects) can occur with all vaccinations, regardless of the pathogen or vaccine involved. The situation is the same with COVID-19 vaccines. Pain at the injection site or flu-like symptoms (also as a vaccination reaction) often occur following vaccination and are usually nothing to worry about. In fact, they are a sign that the immune system is reacting as it should. The following chart shows typical vaccination reactions that can occur shortly after a COVID-19 vaccination and which usually disappear in a matter of few days.

For Germany, as soon as a vaccine has been approved, the Paul Ehrlich Institute (PEI) keeps a central record of all reported adverse effects (side effects) irrespective of the manufacturer. By evaluating both national and international reports, the participating authorities and pharmaceutical companies ensure that extremely rare risks are also documented that only become visible after a very large number of vaccinations have been administered. The vaccines are also monitored following approval in order to gain ongoing knowledge of their safety in differing population groups and to be able to react as appropriate.

This article on Vaccine Reactions and Side Effects after Coronavirus Vaccination provides more information about vaccination reactions and who to contact if you suspect you have a vaccine complication.

Prof. Kremsner from Tübingen University Hospital on the safety of COVID-19 vaccines

How likely it is that previously unknown adverse effects will be detected in long-term studies?

“It’s highly unlikely that long-term effects will be detected. While they can’t be completely ruled out, we usually see adverse effects shortly following vaccination. These can be well documented as they are seen at an early stage in the approval studies, in the Phase III trials and then shortly after the vaccine has been widely administered. So far, we’ve seen nothing to give cause for concern and we’ve been monitoring the first vaccinations for the past six months. Things are looking good. Approvals have not been rushed everywhere as they were in some countries like Russia and China, or the US and the UK for that matter where things went even faster. In the EU, the European Medicines Agency (EMA) has taken its time to really study and evaluate the vaccines. I think we can rely on that process.”

Why vaccination is important

COVID-19 vaccination is an important tool in paving the way out of the pandemic and in saving people’s lives. The more people that are vaccinated against COVID-19, the harder it is for the virus to spread – and the more infections involving severe and fatal cases can be prevented.

The number of people who have already decided in favour of COVID-19 vaccination is recorded in a continuously updated database – the Impfdashboard – maintained by the Federal Ministry of Health. The map of Germany shows the places around the country where vaccinations can be received.