Information about vaccination are evolving over time. The more experience with vaccination we have and the more vaccinated people can be observed and regularly examined, the more data usable in practice we have. Vaccines that have been gradually developed in Czechia and the whole world were thoroughly tested before they were put on market. Every pharmaceutical company was, of course, testing exclusively its own developing vaccine and based on its research set the most appropriate immunization schedule that it stated in the summary of product data. Only later on, when more vaccines were available, it was possible to launch studies focusing on their potential combining. The results of such studies start to be gradually available. The most ideal for revaccination seem to be so called mRNA vaccines (Spikevax/Moderna, Comirnaty/Pfizer) for their high effectiveness and easier modification in relation to other new coronavirus variants. For now, these two vaccines are the only ones allowed for revaccination, on the basis of a special measure by the Ministry of Health. Combining vaccines is also possible in case of uneven distribution of vaccines in Czechia. Those are especially situations when a person interested in booster dose does not have a close vaccination centre offering vaccine with which he or she was previously vaccinated with near their place of living. However, for the basic vaccination it is still preferred to get vaccinated by the same vaccine.