Currently 48 vaccines against corona infection are in clinical development, three of which are close to approval. For health care systems, including those of other countries, the distribution of vaccine doses is the greatest challenge to ensure that as many people as possible can be vaccinated in a short time to be protected from the SARS CoV-2 virus. Covid-19 disease cannot then break out in the first place or at least take a milder course. Accordingly, all Covid 19 vaccines are most commonly divided into four vaccine groups:
1. live vaccines: contain the pathogen in a weaker form so that it cannot cause illness. Examples of live vaccines are the Measles Mumps Rubella Immunoprotection. Live vaccines are currently still in pre-clinical phases.
2. dead vaccines: contain killed pathogens or only fragments of the viruses. They too cannot cause illness and are usually provided with so-called active agents. They usually have fewer side effects than classic vaccines because virus components are produced artificially or are separated from the virus with „molecular scissors“. However, they are also expected to produce weaker immune responses. A vaccine from the US manufacturer Novavax is currently in Phase III trials. Others are still in development.
3. vector vaccines: The basis for these vaccines are so-called vaccine viruses that are harmless to humans. These attenuated vector viruses have the task of introducing genetic material from the SARS-CoV-2 pathogen into human cells so that an immune response can be triggered, as the example of the Ebola vaccine shows. There is a good research basis for vector vaccines. They stimulate the immune system of the vaccinated person well, but the tests for application in the human body are complex and intensive.
4. RNA vaccines: RNA stands for ribonucleic acids, which are administered intravenously to a patient as a solution. in human cells, the genetic material, the so-called messenger RNA (mRNA), is then recognized as the enemy. With the help of the nucleic acids and a viral protein produced in the body, an antigen is constructed against which the human body is now able to produce antibodies. The advantage of this method is that a rapid production of such vaccines in large quantities is possible. However, not a single manufacturer has yet received approval. However, Biontech/Pfizer are close to approval, so that the vaccine may be ready for use in vulnerable groups in December.
What all vaccines have in common is that parts of the virus, the attenuated virus itself or other active ingredients produced by pharmaceutical companies help the human organism to form defense cells, i.e. antibodies, which can act against the antigens. Like other viruses, the SARS-CoV-2 virus requires a host cell to multiply and uses specific receptors on the surface of the host cells to dock. Vaccines, however, try to stop this multiplication by preparing the body of the vaccinated person for contact with the enemy „virus“ by initiating the production of antibodies.