On the opposite - if this is true Russia has reached the level of collective immunity and the Russians are the least dangerous people in the world coronavirus wise because it is contagious only the first few days of the illness.
I have read the herd immunity was at 70% (sorry I don't have the source), I don't know how it was calculated and how true it was. Nevertheless, any % more people immunised tends to lowers the risks; although it may prove different for people vaccinated or equipped (in the CoViD 19 case) specifically to target zones of the spike protein and not the whole virus, because new variants (particularly the South African and the Brazilian variants; the three variants, having heavily mutated on this protein and not elsewhere, may have been "selected", involuntarily of course, either by vaccine trial or by a treatment both a mutagen and targeting this protein, like on this poor Boston patient who produced several mutations along his illness) may not be as much hampered as the viruses taken as bases by pharmaceutical companies.
And with the ADE and ERD effects, which may be the cause of the higher virus shedding by people who get the flu in spite of being vaccinated (and is likely to happen with CoVid though a little part of it have been addressed), it becomes really difficult to get an idea of what will happen. This article is very interesting, plus nearly all comments and links which complete it, particularly since tests about the new variants :
https://blogs.sciencemag.org/pipeline/archives/2020/12/18/antibody-dependent-enhancement
Among the links provided, I found these two among the most useful :
https://www.nature.com/articles/d41586-020-00502-w
https://www.biorxiv.org/content/10.1101/2020.12.18.423358v1.full
About shedding 6x more virus (flu case) :
Lack of human data on influenza virus aerosol shedding fuels debate over the importance of airborne transmission. We provide overwhelming evidence that humans generate infectious aerosols and quantitative data to improve mathematical models of transmission and public health interventions. We...
www.pnas.org
To sum up, we don't really know what will be the effects (positive or negative) on numbers of contamination, either of widespread natural antibodies from earlier contamination, or of widespread vaccination or antibody production device. Prudence is really key for everybody, this while the UK variant has 2,4x more affinity to ACE than previous ones and models of recombination between it and South African or Brazilian variant may have 13,5x more, which would make them really very contagious.
Plus, the 50% was for Moscow only, the most affected area, not for the rest of Russia (though all possible Russian Worlds skaters come from Moscow or St Petersburg I think?)