The World Health Organization announced the development of recommendations due to a new strain of the corona virus. The document will be presented in December. As told to RIA Novosti by an international organization, the work is carried out by a technical advisory group, which meets periodically to update materials on the composition of vaccines. It will publish recommendations on strain PJ.2.1 next month. Information on genetic evolution and epidemiology, as well as data on antigenic characteristics, will be analyzed.