Dead vaccine
A dead vaccine is a vaccine that does not consist of replicable pathogens , but of individual components.
properties
Toxoids , inactivated pathogens (whole-particle vaccines), conjugate vaccines , split vaccines and subunit vaccines are used as dead vaccines . A borderline case between dead vaccines and live vaccines is the modified vaccinia Ankara virus , which can infect cells in the vaccinated but is not replicated in these cells. In contrast to dead vaccines, live vaccines consist of pathogens that can still replicate or at least infect (e.g. smallpox vaccines ).
Different live vaccines or inactivated vaccines can be administered simultaneously. However, live vaccines can induce interferon , which suppresses further infection. Therefore, live and dead vaccines should be given at the same time. If vaccination is not carried out at the same time, the interval between two live vaccinations should be at least four weeks. This does not apply to dead vaccines or a combination with them.
Toxoid vaccines
Toxoid vaccines are made by fixation of toxins . The toxin loses its toxicity , but the change is small enough that an immune reaction is generated that also acts against the non-fixed toxin in the event of a later infection. Examples of toxoid vaccines are the diphtheria vaccine , the pertussis vaccine and the tetanus vaccine and the combined DTP vaccine .
Inactivated vaccines
Inactivated whole particle vaccines are created by fixation of purified pathogens. Examples of inactivated vaccines are the cholera vaccine , the hepatitis A vaccine , the rabies vaccine, and the polio vaccine .
Split vaccines
Fissile vaccines are created by fixing and dissolving the lipid bilayer with surfactants or polar organic solvents . Examples of split vaccines are some influenza vaccines .
Subunit vaccines
Subunit vaccines consist of purified antigens , some of which are produced recombinantly . Examples of subunit vaccines are some influenza vaccines , the HPV vaccine, and the hepatitis B vaccine .
Conjugate vaccines
Conjugate vaccines consist of a purified antigen, which is then coupled to another carrier molecule. The toxoid of diphtheria toxin , the toxoid of tetanus toxin or the capsule material of Neisseria meningitidis are used as carrier molecules . An example of vaccination with a conjugate vaccine is HIB vaccination , some pneumococcal vaccines, and some meningococcal vaccines .
Mode of action
Inactivated vaccines can be broken down quickly, so that multiple vaccinations must be given in order to induce a strong immune reaction. Therefore, after the first vaccination, you vaccinate repeatedly and at certain intervals (booster vaccinations).
During the primary vaccination course, the B lymphocytes produce IgM antibodies with low affinity using T helper cells (CD4 + T cells) . The proportion of specific IgG antibodies then increases continuously. T cells form an immune memory, and when the antigen is presented again through booster vaccinations, a booster effect (greatly accelerated immune response) is made possible. If an immunological memory is built up using T and B cells, disease can be prevented with the same antigens.
By activating the B-lymphocytes and T-helper cells, a humoral immune response is generated, but not a cellular one, as is the case with a live vaccination .
Inactivated vaccines contain immune-stimulating adjuvants - mostly aluminum adjuvants - in order to sufficiently maintain the immune response to the antigens contained in the vaccines. Here, the antigen is absorbed on, for example, aluminum hydroxide , MF59 or AS04 . In the past, inactivated vaccines also contained preservatives such as thimerosal or thimerfonate . As a result of technical progress, aseptic production has been improved so that single-dose formulations such as children's vaccines can be produced without preservatives.
pregnancy and breast feeding period
According to the current recommendations of the Robert Koch Institute responsible for this in Germany , due vaccinations with dead vaccines can be administered to expectant mothers in the second and third trimester of pregnancy without hesitation; vaccination against influenza is particularly recommended. In the first third , on the other hand, in order to rule out any risk to the child, only those vaccinations that are urgently indicated for the individual should be carried out . During the subsequent breastfeeding period , vaccinations with dead vaccines are generally possible without restrictions.
Experimental dead vaccines
In the course of vaccine development , peptide vaccines , DNA vaccines and viral vectors are investigated. Peptide vaccines are mostly peptides produced by peptide synthesis . DNA vaccines mostly consist of plasmids that encode the antigen. Viral vectors are based on viral particles that deliver the vaccine gene into a cell.
literature
- Charles Janeway , et al .: Immunobiology . 6th ed. ISBN 0-8153-4101-6 . The 5th English edition is available online on the pages of the NCBI Bookshelf (online) .
- Stanley A. Plotkin, Walter A. Orenstein, Paul A. Offit: Vaccines. Elsevier Health Sciences, 2008. ISBN 9781416036111 .
Individual evidence
- ↑ Lothar Rink, Andrea Kruse, Hajo Haase: Immunology for beginners. Edition 2, Springer-Verlag, 2015. ISBN 9783662448434 . Pp. 138-139.
- ↑ Herbert Hof, Rüdiger Dörries: Medical Microbiology . 5th edition. Georg Thieme Verlag, Stuttgart 2014, ISBN 978-3-13-125315-6 , p. 731 .
- ↑ a b c d Herbert Hof, Rüdiger Dörries: Medical Microbiology . 5th edition. Georg Thieme Verlag, Stuttgart 2014, ISBN 978-3-13-125315-6 , p. 726 .
- ↑ a b Can I be vaccinated during pregnancy and breastfeeding? Robert Koch Institute , April 17, 2015, accessed on February 2, 2020 .