How a vaccine is developed

Vaccines are among the greatest achievements of modern medicine. The development and research of a vaccine is usually a long process, usually lasting several years. A vaccine goes through these stages from development in the laboratory to being averted in vaccination centers and doctors' offices:

1. Pharmaceutical Quality:

First, the pathogen is analyzed. The components of the virus to which the human immune system reacts and forms antibodies are tested.

2. Preclinical development:

This results in the first vaccine variants, which are tested in cell cultures or even animal experiments for immunogenicity (ability of the antigen to trigger immunization), efficacy and safety.

3. clinical testing:

Only when, after extensive testing, it has been demonstrated that the vaccine is of the appropriate good quality, meets all high standards, and can be manufactured safely, do clinical trials on volunteer study participants:in three phases.

**Phase 1 usually involves between 20 and 100 healthy volunteers. Laboratory tests are used to determine whether the vaccine elicits the expected responses (immunogenicity). First and foremost, however, safety and tolerability are tested.

**Phase 2: If phase 1 is successful, several hundred volunteers will be tested to determine the best possible vaccine dosage for optimal protection and to determine what side effects may occur.

Phase 3: In the final phase of clinical testing, the vaccine is tested in several thousand (in the case of COVID-19 vaccines, several 10,000) volunteers in the target population. This trial will show how effective the vaccine is in protecting against the disease compared to a control group (e.g., placebo) and what, if any, side effects may occur and with what frequency.

4. peer review and approval:

The collected data and study results are reviewed by independent institutions and authorities as part of the approval process.

5. Large-scale production and delivery to vaccination sites

Safety first principle

Before a vaccine can actually be used, it must once again undergo a strictly regulated review process after clinical testing in order to receive regulatory approval. An official approval process is a prerequisite for a vaccine to be launched on the market. In the EU, and thus also in Austria, vaccines are subject to strict approval criteria. After all, the safety of vaccines is paramount. The national health authorities and the EU Commission ensure that all studies are scientifically sound and ethically correct. These include, for example, the European Medicines Agency (EMA) or, in Austria, the Federal Office for Safety in Health Care (BASG).

Permanent monitoring of vaccines

To ensure that vaccines remain safe over the long term, vaccines are continuously monitored even after they have been approved. And this is as long as they are on the market. Reporting suspected cases of adverse reactions or failure to achieve expected efficacy is a central pillar for assessing vaccine safety. Healthcare professionals are required to report such cases. Patients can also report suspected adverse reactions. In Austria, this information goes to the Federal Office for Safety in Health Care (BASG). All reports are collected throughout the EU. Analysis of this data makes it possible to identify a possible new risk, evaluate it and, if necessary, act accordingly.

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