SARS-CoV-2 vaccines and reaction of the immune system. Cantheepidemic spread of the virus be prevented by vaccination?

Abstract

Since the end of 2019 a new coronavirus, SARS-CoV-2, first identified in Wuhan, China, is spreading around the world partially associated with a high death toll. Besides hygienic measurements to reduce the spread of the virus vaccines have been confected, partially based on the experiences with Ebola virus vaccine, based on recombinant human or chimpanzee adenovirus carrying the spike protein and its ACE2 receptor binding domain (RBD). Further vaccines are constructed by spike protein coding mRNA incorporated in lipid nano vesicles that after entry in human cells produce spike protein. Both vaccine types induce a strong immune response that lasts for months possibly for T-cell immunity a few years. Due to mutations in the coronavirus genome in several parts of the world variants selected, that were partially more pathogenic and partially easier transmissible - variants of concern (VOC). Until now vaccinees are protected against the VOC, even when protection might be reduced compared to the Wuhan wild virus.An open field is still how long the vaccine induced immunity will be sufficient to prevent infection and/or disease; and how long the time period will last until revaccination will be required for life saving protection, whether a third vaccination is needed, and whether revaccination with an adenovirus-based vaccine will be tolerated.